Plant Genetic Resources and Their Management in Bulgaria
Dimitar Stoyanov
Summary
The Bulgarian flora includes many local varieties and wild relatives of cereals, forage grasses, legumes, and temperate fruits. Due to its geographical situation and climatic and edaphic variability, Bulgaria is also a secondary center of diversity for most of the cultivated plants introduced from other centers of origin. Over many ages, environmental conditions and selective pressures in Bulgaria have allowed an enormous diversity of tomatoes, peppers, beans, tobacco, melons and watermelons, corn, and other crops to develop.
The importance of plant genetic resources for the development of Bulgarian agriculture was first recognized at the beginning of this century. The collection, study, conservation, and use of the existing genetic diversity began in this period, focusing at first on local populations of bread and durum winter wheat, beans, and the basic vegetable crops. These were given priority due to the major role they play in providing livelihoods for the Bulgarian population. Bulgarian scientists quickly realized the importance of the ideas of the Russian scientist Vavilov, and active studies of the local plant resources began in the early thirties. A Department of Plant Introduction and Plant Resources was created within the Institute for Plant Genetics and Breeding in Sofia.
In 1978, the National Institute for Plant Genetic Resources was founded in Sadovo, allowing scientists to undertake more detailed field and laboratory studies to characterize the germplasm and to conserve it through long-term storage. The collection of local cultivated plants and their wild relatives has had priority in the last several years. Most accessions are characterized according to international descriptor lists. The information is being computerized and made available for use. The publication of catalogs and inventories now allows people who need this information to locate it more easily. The research program is directed toward the conservation of germplasm as a way of preserving genetic diversity. Specimens with characters valuable for the breeding programs - for example, resistance to drought, cold, disease, and other stress factors - are being conserved in the collections.
This report gives information about the accessions of local crops and their wild relatives from different floristic regions of the country. It also includes conclusions regarding gaps in the national program for the conservation and use of germplasm. Endemic species and varieties requiring special attention are noted. Attention is also given to areas rich in species diversity that should be studied in greater detail and included in the national network of protected areas. These areas should receive special protected status as areas devoted to in situ conservation. In view of global climatic changes and other changes that will inevitably occur in agriculture, some local species are being seen as potential new crops. A new scheme to manage plant genetic resources in response to social and economic changes in the country is proposed.
Historical Review
A national network of Agricultural Experimental Stations and Universities began to be built immediately after the liberation of Bulgaria from Turkish rule. The research programs followed in the experimental stations included studies on the improvement of the more important economic crops. Thus, at the end of the last century and into the beginning of this century, the conscientious and purposeful study of the plant germplasm in Bulgaria began.
K. Malkov (1906) described local wheat varieties and began research on their improvement. That same germplasm later became - in fact remains - part of the genetic composition of modern varieties. Bulgaria is a primary center for many cereal and grass and legume forage species. The importance of the country as a secondary diversity center for other plants introduced from distant geographic regions very quickly became evident. Such is the case, for example, with the rich diversity of local bean accessions described by Gradinarov (1939) and local pepper accessions described by Popov (1940). These two papers are still important works in the field.
Intensive collection and evaluation of local varieties began in the 1920s and 1930s. The adaptations of these varieties to local edaphic and climatic conditions was highly appreciated, as was the necessity of their use in breeding programs. However, the lack of facilities for preservation of collected materials and, most important, the lack of a general national policy for the management of plant genetic resources, led to the dispersal of most of the collected material.
The collaborative work of D. Kostov and the well known Russian geneticist N. I. Vavilov presented an important opportunity for Bulgaria. Most of Kostov's research and educational activities were devoted to exotic germplasm and its importance in transferring certain characters and qualities to the cultivated plants. After his return to Bulgaria, Kostov spent most of his time trying to build up a Department for Plant Genetic Resources in the Central Experimental Institute for Agriculture. Thus was created the first centralized body for plant genetic resource management. The department would later be expanded as part of the Institute for Breeding and Genetics, but its work initially emphasized the introduction of germplasm from other countries.
From this period until 1982 there were no facilities for the long-term storage of the accessions. This led to their frequent regeneration. With the continuous increase of the collections and the lack of suitable preservation facilities, the period between successive regenerations became longer and most of the accessions were extensively damaged.
In 1977 the Department for Plant Genetic Resources moved to Sadovo where, together with the Agricultural Experimental Station and the Experimental Station for Variety Maintenance, it became part of a new large-scale center for plant genetic resources. The Bulgarian government and the United Nations Food and Agriculture Organization (FAO) through a collaborative project of the United Nations Development Programme provided the necessary conditions for research in the field of plant genetic resources. A seed storage facility for the long-term preservation of the accessions, with equipment for the study and evaluation of the accessions, was built. This allowed the research program to improve considerably. Priority species have since been identified and a plan for systematic collecting missions in the country developed.
For 20 years Bulgaria has been an active participant in the United Program of the East European Countries, directed by the Central Experimental Institute for Agriculture (VIR) in Saint Petersburg. In the Scientific Council of the program, problems concerning working methods are discussed. Commissions are established and descriptor lists for some of the most important crops created. The participating countries cooperate in organizing expeditions to collect valuable germplasm. Results from these studies are periodically published.
Bulgaria has participated in the European Cooperative Program since its inception, and has taken part in the ECP's effort to create a crop network. Our country is also a member of the FAO Commission for Plant Genetic Resources. After the creation of the Institute at Sadovo, Bulgaria adopted an open policy concerning its plant genetic resources. During this period, Bulgaria has collaborated with the International Centre for Agricultural Research in the Dry Areas (ICARDA), the International Board for Plant Genetic Resources (IBPGR), and the United States and other countries.
A number of steps have recently been taken to improve the management of plant genetic resources in Bulgaria. An important study of the collections has been initiated. A catalog of the accessions in long-term storage was published. Records of newly received accessions are published annually. A data base comprising the results of accession evaluations has been created, and is at the disposal of the users. The data base will be used to create catalogs and to participate in international data networks as they are created.
Major Gaps in Knowledge
Although the program of field and laboratory evaluation of accessions has been more active over the last 10 years, it is satisfactory only for local varieties. Thorough information about the wild relatives of cultivated plants is lacking, as are (even more importantly) evaluations of bioclimatic characteristics and of resistance to winter, cold conditions, and economically important diseases and insects. For some species and varieties, it is important to know their capacity for improving soil fertility, their ability to grow on acid soils and soils of low productivity, and their other soil protection capabilities.
In the case of legume species, only seeds have been collected. The failure to collect the specific root bacteria characteristic for each species and habitat is an omission. As a result, regeneration and cultivation of some of the most promising species has been difficult.
We lack knowledge from prebreeding studies on the best and most effective methods for transferring genes responsible for the expression of desirable characters and qualities. Neither have studies evaluated the possibility of distinguishing spontaneous interspecies hybrids that could be used as natural bridges in breeding programs.
Methods of pollination control when regenerating accessions and their influence on narrowing the genetic base of populations of cross-pollinated plants have also been inadequately studied. Expansion of these studies will make it possible the choose the most suitable method for each species.
Information is lacking on the potential for cryopreservation of pollen, tissues, and whole plant parts, both of vegetatively propagated plants and of seed-propagated plants that are difficult to preserve by orthodox methods.
The use of in vitro techniques of preservation has been studied only for a few species (potatoes, vines, chrysanthemum). Little is known about the influence of in vitro preservation conditions on the genetic integrity of the accessions.
Another gap is the use of Restriction fragment length polymorphism (RFLP) analysis for the study of different species. Though isozyme and storage protein analysis has been undertaken in the last few years to determine the diversity and duplication of accessions, the information is still inadequate.
Another basic gap is the lack of research on in situ conservation sites - especially as concerns the size of the populations within them, the relations of the species they contain, and the influence of the local climatic and edaphic factors.
Up until now, collections have been created to distinguish certain characters, but in the future attention should be given to the separation of genetic sources as donors of specific characters.
Assessment of Present Conditions
The importance of plant germplasm for the success of breeding programs, for the development of modern agricultural systems, and for the status of ecological conditions has become more greatly appreciated. For the last few years - since the establishment of the Institute for Plant Genetic Resources in 1978 - clearly defined priorities for the study of plant genetic resources have been followed. Attention is again being paid to the exploration of local plant diversity. A program defining the collecting missions for the period 1978-1988 was created. Expeditions were constantly active in the field, with the goal of enriching the collections and preserving existing biological diversity.
Because of structural changes in agriculture and the constant adoption of new crop varieties, the diversity of local varieties of maize, wheat, chick-pea, lentil, barley, apples, pears, plums, tomatoes, pepper, onion, and other crops was doomed to vanish as their acreage became more and more limited. Many interesting plants, including some very rare species and some wild forms endemic to Bulgaria, are now dangerously decreasing and even vanishing due to promiscuous gathering by amateurs, tourists, and herb-collectors without corresponding effective measures to assure their propagation and preservation.
The foundation for the organized and scientifically based collection and study of plant genetic resources in Bulgaria was laid in 1939 by the aforementioned D. Kostov. In the early 1960s the Department for Plant Genetic Resources organized seven expeditions, allowing a certain proportion of the species and varietal diversity of local forms to be collected. Priority in the collecting missions was given to local forms of field, vegetable, and fruit crops. These old local ecotypes had developed important regional advantages due to the long period of selection and primitive breeding. Their characters and qualities made them valuable as donors in the breeding programs. Some of them may eventually be used widely in agriculture, either directly or after a certain period of prebreeding.
In the case of cereal and legume species, attention was directed toward old local varieties and populations of garden and field beans, maize, lentil, broad beans, vetch, wheat, rye, and oats. Other old local forms were found in the vegetable group - tomatoes, cabbage, cucumbers, watermelons, melons, pumpkins, spices, and others. Special attention in this program was paid to the horticultural regions around Gorna Oryahovitsa and Tirnovo. In the Blagoevgrad district, Kyustendil, Strandzha-Sakhar, and Loudogorie, efforts focused on collecting the diversity of garden, field, and binding beans. For diversity of watermelons and melons, collecting work focused on the regions around Pleven, Vidin, Razgrad, Shumen, Yambol, and Svilengrad. In the cooperative and private gardens, researchers looked for old local varieties and clones of seed and stone fruit varieties, vines, and nut-bearing species. Special attention was given to the "spur" type accessions: those characterized by slower growth, earlier fruit formation, differential ripening, good taste, and other horticultural qualities, including the length of preservation under normal conditions, and superior resistance to diseases and insects.
The second priority in these expeditions was the collection of local wild or semi-wild plants possessing useful qualities and characters, including high content of valuable compounds, cytoplasmic male sterility, capacity to restore soil fertility, high degree of disease and insect resistance, and resistance to extreme meteorological conditions.
Three types of expeditions have been carried out: complex, specialized, and individual. One specialized expedition undertook to review and collect the diversity of fruit species in the areas of the Rila, Rhodope, and Strandzha Mountains, the Stara Planina from the western border to Cape Emine on the Black Sea, and the afforested belts of northeast Bulgaria and the mountainous regions of Malashevska, Konevska, Osogovska, Ograzden, Belasitsa, and Pirin. Another specialized expedition reviewed and collected the diversity of wild vines and old local varieties along the southern Black Sea coast, the rivers Kamchia, Ropotamo, and Veleka in the Strandzha region, the Petrich-Sandansky region, Konevska, Osogovska, Ograzhden, Belasitsa, and Pirin Mountain. A third specialized expedition encompassed the cereals, legumes, and ornamental plants in the Rhodope Mountains, along the Black Sea coast, in the Sredna Gora, and in Strandzha-Sakhar region.
Three collecting groups were formed to gather local varieties over the whole territory of Bulgaria. Their attention was directed more toward areas along the boundaries and in the sub-Balkan settlements where varieties have changed much more slowly.
For financial reasons this program was not fully completed. Over 2,300 accessions were gathered during its active collecting phase. In the case of the fruit species, the accessions were only marked and a very insignificant part of them (mainly the walnuts) were collected. The collected materials were subject to complex study for identification and agronomic evaluation. These data provided a basis for card-indexing areas deserving of more detailed study for in situ conservation of the wild relatives of the cultivated plants.
The complex study of the collected Aegilops accessions indicated that they were highly unique. Some of the Aegilops triaristata showed resistance to powdery mildew and brown and yellow rust. Most of the Ae. biuncialis, Ae. ovata, and Ae. triuncialis accessions are resistant to brown rusts. Some of the Ae. triaristata and 70% of the Ae. ovata accessions are resistant to yellow rust. Complete immunity to powdery mildew was shown in all Ae. triaristata and Ae. ovata accessions, and 50% of the Ae. biuncialis accessions. Complex field resistance to the above mentioned diseases was evident in 7 accessions of Ae. ovata, 3 accessions of Ae. triaristata and one accession of Ae. triuncialis.
The collection of forage legumes includes seed legumes (pea, vicia, vetch, lupine) and annual and perennial legume grasses (clover, alfalfa, sainfoin, and others). All cultivated species of this collection have relatives in the Bulgarian flora. That is to say, Bulgaria is one of the centers of diversity for the above mentioned forage legume species.
Most widely represented in the wild flora of the Trans-mediterranean zone (the plain and semi-mountainous part of southern Bulgaria) is the family Fabaceae, followed by Compositae and Gramineae (Stoyanov, 1922, 1930). Within the Fabaceae, the genus Trifolium has the highest species diversity (55 species). In the Trans-mediterranean zone from 0 to 600-700 m a.s.l., the most widespread group is the annual clovers (31 species), which are very well adapted to the dry climatic conditions of southern Bulgaria. The Bulgarian flora offers significant possibilities for new forage species, not only as initial breeding material for our own agricultural use, but also for that of other countries. Together with ICARDA (based in Syria), the Institute of Food and Agricultural Sciences (IFAS, based in Gainesville, Florida, USA) and the AMGRC (based in Adelaide, Australia), collecting missions for legume and cereal forage grasses were conducted in 1988, 1989, 1990, and 1992. As a result, ex situ collections of Trifolium, Medicago, Vicia and other legumes were established.
The gradual study of these collected materials and their ecological plasticity (especially among the annual species) has revealed their important potential as forage genetic resources. This potential falls into several categories.
1. Species suitable for dry conditions, especially stony and hilly areas that cannot be irrigated. Alfalfa, a basic forage in Bulgaria, does not do well under dry conditions, and its use in dry areas and periods is not advisable. The dry climate, especially during the last few years, oblige us to use the wild plants best adapted to these conditions as a contribution to solving the forage problem. Thus it can be said that the historical process of transforming wild plants into cultivated ones continues, and will continue as long as the plant genetic resources in nature exist.
2. Species and forms suitable for eroded soils. In addition to alfalfa, clover, and sainfoin, species of the genus Astragalus could be used. They have creeping stems and are suitable for slopes.
3. Forms and species suitable for unfertile soils and for improving soil fertility.
4. Species suitable for initial breeding material (alfalfa, white and red clover, vetch, lupine).
Difficulties related to germination, seed formation, and regeneration and reproduction exist for some of the wild species. Research is now being directed toward the identification of accessions that germinate more easily, have better seed formation, and are easily adapted to environmental conditions.
The predominant local cereal grass accessions are those of the species Dactylis glomerata, Festuca rubra, Lolium perenne, Bromus inermis, Phleum pratense, and Poa pratensis. Old local accessions of the legume crops, maize, sweet sorghum, broom corn, bean, and fruit species can still be found. There are 850 local maize accesions in long-term storage. One thousand and thirty-three accessions of durum wheat, collected in the early 1960s from the southeast and southwest part of Bulgaria, are being preserved. The best represented group is the legume crops, with a total of 1954 local accessions.
Many of the local tomato, pepper, melon, bean, and pumpkin accessions are being used in breeding. As a result of a complex study, valuable accessions of tomatoes with high dry matter content, biologically active substances, and resistance to economically important diseases have been identified. Two new tomato varieties, Vihren and Trapezitsa, have been created, based on local germplasm. Through individual selection in populations of the collected garden beans, the varieties Trakiyski and Ilinden have been created. They are characterized by early maturity, high productivity, and tolerance to bacterial diseases. In the last few years breeding lines developed in different breeding programs have been enlisted in the national gene bank. Very often these possess certain characters and can be used as genetic sources.
The diversity of relatives of the fruit crops is great. Endemic species typical for some of the floristic regions are to be found here also. The genus Pyrus L. (pears) is represented by P. pyraster Burgsd., P. amigdaliformis Will., P. eleagrifolia Pall., P. nivalis Jacq., and P. sativa or P. communis subsp. sativa Stiy. et Stef. In addition to P. eleagrifolia, a subspecies bulgarica typical for the southern Black Sea coast, the slopes of the eastern Stara Planina Mountains, and Strandzha Mountain, has been established. It is resistant to drought and cold and is suitable as a genetic source for stock breeding.
A great diversity of clones of local varieties exists. They differ in terms of growth strength, form and size of fruits, taste and structure of fruit flesh, maturity rate, disease resistance, and other characteristics. The Malus Mill. genus (apples) is represented in the Bulgarian flora by M. sylvestris Mill., M. dasyphylla Borkh., M. praecox, and M. domestica or M. pumila var. domestica Schneider. The genus Prunus (cherries, apricots, peaches, plums) is best represented and is found throughout Bulgaria. Most of the collected and card-indexed accessions are of P. spinosa L., P. cerasifera Shrh., P. insititia, and P. domestica L. The genus Cerasus Juss is represented by C. mahaleby (L) Mill., C. avimu (L) Moench., C. fruticosa (Pall) G. Woron, and C. vulgaris Mill.
The genus Amygdalus originated in southwest Asia and North Africa, from which different varieties of A. communis were introduced long ago. It is grown in small gardens alone or with vines, as well as in single plantings in yards and along roads. Its density is greater along the Black Sea coast, in northeast Bulgaria, on the Danubian plain, and in the eastern Stara Planina Mountains.
Significant areas of forestland were planted with seeds of Juglans regia, Persian (or English) walnut, in the period 1950- 1965. These plantings represent an extremely fortunate circumstance for the collection of valuable genetic material for this species.
A great diversity of tree- and bush-type hazelnut, Curilus avelana, exists in the mountainous areas.
During the last several decades, fruit production in Bulgaria was collectivized and large orchards were created in which only a few varieties of a given species were grown. This fact placed before us the problem of accepting and realizing a program to collect, study, and protect the old local varieties. According to that program, active collection activities were carried out throughout the country. These activities were directed mainly toward regions affected by industrialization, tourism, active wood cutting, and other pressures.
In accordance with the areas of distribution of the different fruit species and the specialization of the research centers, several ex situ collections were created: for the apples, pears, cherries, morellos, and peaches at the Fruit Growing Institute in Plovdiv; for apricots at the Apricot Experimental Station in Silistra; for plums at the Plum Experimental Station in Dryanovo; and for almonds and peaches at the Experimental Station at Pomorie.
An inventory program for the fruit tree collections has been carried out in several stages: development of a passport and evaluation form to gather information on incoming varieties; filling in of information gaps; and the computerization of collected information in the so-called National Register and card index. Nine hundred and eighty varieties are enlisted in the National Register. As the planned program is realized, it offers the possibility of creating a National Information Bank for the country's existing fruit species genetic resources, with constant updating of the National Register and centralization of the work on these resources. Unfortunately, this work has been hindered due to financial difficulties, and remains incomplete. Only 120 nut accessions have been collected in the ex situ collection. The rest are marked, and the financial prospects are such that they may be collected in the next few years.
The gene bank in Sadovo maintains three types of collections from the point of view of conservation: short-term storage, an exchange collection, and long-term storage. The accessions for long-term storage are kept in the basic collection. In short-term storage are the accessions that are being studied, regenerated, or reproduced. In the exchange collection are the accessions intended for international exchange.
The technology for long-term storage is based on the ability of most species to sustain dehydration and cooling, with temporary slowing or termination of physiological processes, thus slowing down the very process of aging. The first experiments in long-term storage began at the National Institute for Plant Genetic Resources in 1981. After three years of testing, a technique suitable for 192 species of cultivated and wild plants was adopted. This involves storage in hermetically sealed glass vessels and, in the last few years, in special three-layered folio envelopes. Storage is carried out at -18°C after an initial treatment of the prepared accessions at 8°C and 0°C (to eliminate the hydrothermal effects of quick cooling). During the storage period, the temperature in the chambers, the hermeticity of the package, the seed humidity, and the viability of seeds are controlled. Checks of the accessions are performed once every 3-4 years. Every check includes measurement of the temperature of the seeds and dehermetization in a drying chamber. Information about the storage program is computerized.
Results from control checks of more than 6,000 accessions are positive. With the exception of several accessions, no lowering of seed viability was detected over a period of 10 years. There are currently 25,831 accessions in long-term storage.
The management of data and documentation of plant genetic resources is connected to the computerization of the passport and evaluation information. The passport information is relevant for plant resources that arrive at the institute through international exchange, collecting missions, and exchanges with Bulgarian breeding institutions. Each of these files includes passport data characteristic of the different plant accessions, in accordance with international classifications. Data from the characterization and evaluation of the accessions in the field goes into the evaluation data files for the different crops. These data files include information on 60-80 characters, depending on the crop.
Historical, Present, and Potential Threats
The constant threats to the survival of the plant genetic resources of Bulgaria are associated mainly with human activities and global scale changes in the climate and the soils. At the beginning of the century, the plowing of pastures and meadows, the draining of swamps, and the clearing of woods had a strong influence. In some areas, overconcentration of cattle brought about abnormal conditions for the regeneration of some species, limiting the size of their populations and even leading to their extinction.
Intensive agriculture and the constant pressure from new varieties gradually pushed out the old local varieties. Pressure was first exerted upon the wheat, barley, and maize varieties that were grown on larger areas. The process was speeded up by the collectivization and consolidation of land after World War II, and reached its apex in the period 1950-1965.
Intensive development along the Black Sea coast also disturbs the environment and threatens some delicate plant communities, including some with rare species that are relatives of cultivated plants. The building of roads makes even the most remote parts of the country more easily accessible to cars and people. For many years industrial quantities of herbs have been collected from their natural habitats, without care for their regeneration. Pastures are improperly used in the same way.
Gradual climatic changes pose a potential threat to Bulgaria's plant genetic resources. Global warming and frequent droughts over the last ten years have contributed to the expansion of dry areas into zones where some of the rare species belong. Some species have disappeared in the last 10 years. In particular, the species in the family Fabaceae are extremely sensitive.
Increased soil acidity is another great problem, as it hampers the symbiotic relationship of plants and nitrogen-fixing azotobacter. The drying out of the Mediterranean-type vegetation along the rivers of south Bulgaria brought about the disappearance of binding vegetation, especially the wild vines. When whole forests are cut - a phenomenon that still occurs - unique Prunus species are destroyed. With the restitution of the land, orchards and vineyards are being destroyed, some of which harbor old local varieties. The same mistake was made when these lands were first collectivized. In many places, however, mainly in the foothills and mountainous regions, small gardens with old varieties still remain.
Storage itself, if it is not performed properly, can be a potential threat and lead to a loss of genetic diversity. This should be kept in mind when new technologies for long-term storage are considered. When suitable conditions for long-term storage are lacking, frequent and improperly conducted regenerations pose a potential threat to genetic diversity.
Recommendations
In order to provide more efficient management of plant genetic resources, it is advisable that a National Council for Plant Genetic Resources be established. Its duty should be to define a total conservation policy based on priority principles, addressing all problems connected with the collection, study, conservation, and use of plant genetic resources for breeding and other purposes.
There should be, connected with the National Council, working groups for the different crops that carry out projects concerning the collections. These groups should include as members the national curators from the Institute in Sadovo, breeders, botanists, and representatives of non-governmental organizations.
Following the example of other countries, the assistance of non-governmental organizations in attracting the attention of farmers, gardeners, students, and others for participation in the collection and preservation of germplasm should be more actively sought.
A special effort should be made to draw the attention of farmers from different parts of the country to the need for regeneration of old local varieties and even for the propagation of some of them on larger areas. The non-governmental organizations could be in charge of the informational activities, bringing in funds and sponsoring conservation activities.
To improve conditions for ex situ conservation of seeds in the gene bank, drying conditions should be improved and provisions made for safer packing.
For better conservation of the vegetatively propagated and fruit species, a National Repository affiliated with the National Institute for Plant Genetic Resources in Sadovo should be built up.
It is important to secure financial means to develop cryopreservation techniques in the next few years.
More attention should also be paid to in situ conservation through serious study of several unique areas. Special attention should be given to the medicinal plants, and a thorough agronomic study should be undertaken to determine the potential for their cultivation outside the natural habitats. An extension program, focusing on the protection of biodiversity and social and economic development, should be created for the people in these areas.
In order to implement a complete program for biodiversity protection, it is also important to have a system of modern information technology. This is a key factor in the conservation and use of plant genetic resources.
Table 1. State of the Collection
Crops Total No. of Access Access in Long Term Storage No. of Eval Access No. of Domestic/Local from total access 1 2 3 4 5 1. Cereals: 18,155 16,689 11,074 2,297 Bread wheat 5,749 5,355 4,380 67 Durum wheat 1,675 1,491 1,290 1,033 Triticale 662 618 60 Barley 3,386 3,386 1,275 49 Maize 3,155 3,268 1,804 850 Oat 1,340 1,244 1,311 12 Sorgo 736 589 168 29 Millet 157 97 80 Rye 315 278 306 7 Rice 98 43 49 Wheat sp. 503 268 230 Aegilops 379 52 121 250 2. Food and forage legumes: 9,264 4,345 3,314 1,954 Forage pea 1,942 313 400 41 Pea 781 111 781 15 Soybean 917 689 80 Vetch 1,218 1,013 150 390 Lentil 381 195 237 23 French bean 1,500 388 780 1,250 Dry beans 1,120 520 228 152 Faba bean 543 459 518 25 Chick pea 238 203 26 Lupin 136 68 90 2 Other sp. 478 386 50 30 3. Forage grasses: 1,049 596 306 702 Alfalfa 411 127 61 151 Clover 522 18 72 223 Sainfoin 170 50 63 20 Dactylis 236 211 51 218 Brome grass 62 59 50 3 Other perennial 265 181 72 87 4. Oil and industrial crops: 3,013 2,354 1,733 109 Sunflower 577 313 421 42 Raps 283 235 260 2 Sesame 150 116 145 Flax 1,057 943 467 Tobacco 151 141 Brown nut 322 241 320 Poppy 123 123 120 Beta 36 36 Others 360 242 29 5. Vegetables: 4,274 1,638 3,425 1,165 Tomatoes 713 484 682 174 Pepper 615 110 464 264 Cucumbers 1,014 274 960 10 Water mellon 255 93 45 158 Mellon 273 68 128 244 Salad 480 224 410 2 Cabbage 412 65 385 6 Squash 312 122 117 260 Other sp. 418 198 234 47 6. Flowers: 1,034 219 638 50 Temperate fruits 1,950 719 523 Wine grapes 2,050 1,000 268 Total: 40,729 25,831 22,209 7,068 Table 2. Wild Relatives of Cultural Plants in Bulgaria
Legend: * - rare species ** - endemic plant Crops Genus Wild Species Important Species Lupine Lupinus 3 angustifolius*, albus* Lentil Lens 2 ervoides*, nigricans* Chickpea Cicer 1 montbretii* Pea Pisum 1 elatius* Grass pea Lathyrus 27 sativus, cicera, hirsutus Vetch Vicia 32 sativa, grandiflora, pannonica, incisa*, narbonensis, tenuifoli, pisiformis, villosa, ervilia Alfalfa Medicago 16 varia, falcata, carstiensis*, rhodopea**, lupulina, polymorph, arabica, orbicularis, rigidula, minima Clover Trifolium 55 pratense, repens, hybridum, frag, ferum, medium, pannonicum, alpes, subterraneum, resupinatum, nigscens, vesiculosum, retusum*, incarnatum, hirtum, canstantinopolinum* Sainfoin Onobrychis 9 arenaria, lasiostachia, gracili Sweetclover Melilotus 5 albus, officinalis Other legumes Ornithopus, Lotus, Astragalus, Glycyrriza, Coronila 46 O. compressus, L. corniculatus, G. glabra*, C. varia Grasses Dactylis, Lolium, Bromus, Poa, Festuca, Arrena-therum, Phleum, Alopecurus, Agropyron 78 D. glomerata, L. perenne, B. inermis, F. rubra, F. pratense, P. pratensis, Arr. elatius, Ph. pratensis, Al. pratensis, Ag. pectinatum Wheat Triticum 1 aegilopoides: var. aegliopoides, var. boeoticum Goatgrass Aegilops 9 ovata, triuncialis, cylindrica, speltoides, comosa, biuncialis Elymus Elymus 1 sabulosus Rye Secale 2 rhodopeum**, silvestre Oat Avena 9 fatua Beta Beta 2 trigina, maritima Raps Brasica 1 rapa, alba Sinapus Sinapus 5 nigra, alba Other oils Cartamus
Camelina
Crambe3
5
4lanatus
sativa
maritimaCarrot Daucus 3 Lettuce Lactuca 9 Onion Allium 28 schoenoprazum, proliferum, cepa var. aggregatum, victoorialis, atropureum, nigrum, multibulbosum, cyrilly, ursinum, atroviolaceum, ampeloprasum, scorodoprasum, rotundum, sphaerocephalon, margaritaceum, gutatum, amethystinum, oleraceum, rhodopaeum, flavum, vebii, pacloscianum, carinatum, cirrkozu Mint Mentha 7 viridis, nigricans Lemon balm Melissa 1 officinalis Valerian Valeriana 1 officinalis Lavender Lavandula 3 vera Plums Prunus
Cerasus
Amigdalus4
4
4divaricata, spinosa, cerasifera, insititia, domestica
mahaleb, avium, fruticosa, vulgaris
sativa, vebii, nanaApple Malus 4 silvestris, dasyphylla, praecox, domestica (pumila) Pear Pyrus 5 pyrastar, communis, amygdaliformis, elaea-grifolia, sibs. bulgarica, nivalis, sativa Medlar Mespilus 1 germanica Nut Juglans 1 regia Chestnut Castanea 1 sativa Grape vine Vitis 1 sylvestris Blackberry Rubus 11 idaeus Strawberry Fragaria 3 vesca Rosa Rosa 23 canina Hops Humulus 1 lupulus Bibliography
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Preservation of Livestock Genetic Resources in Bulgaria
Tsvetan Dimitrov, Ivana Dimitrova, and Dimitar Vassilev
Introduction
Animal breeding has ancient roots in Bulgaria. Although our country is relatively small in territory, it is characterized by a great diversity of livestock species. This reflects the particular breeding conditions of different regions. In addition, the ethnographic traits and traditions of the people in the different regions have played an important role. This geographic and cultural diversity is a crucial prerequisite for the development of farm animals typical for each region, differing not only by choice of breed but quite frequently by choice of species as well.
The persistence up to the present of such a large variety of livestock could be related to the fact that animal breeding was one of the basic occupations of the population for centuries. As a consequence, various breeds of cattle, sheep, goats, buffaloes, pigs, fowl, horses, and other domestic animals have been preserved and are being bred within the country.
Forage Base and Livestock Breeding Techniques
The arable land in Bulgaria totals 4,649,979 hectares, 83% of which consists of fields, 7% natural meadows, and 7% perennial plants. The remaining area is occupied by artificially cultivated pastures. Of the total area of arable land, 1,955,413 hectares are used for forage production: 47% for fresh forage and 53% for corn forage. In addition, there are 2,035,000 hectares of uncultivated natural pastures, located mainly in the mountainous and semi-mountainous districts. The use of these grasslands is extensive and the amount of forages cropped is limited. Basically these areas are used for free pasturing of sheep and for cattle breeding.
The artificial pastures are owned by state farms and occasionally by research units. Research related to grassland areas is carried out mainly by the Institute of Mountain Agriculture and Animal Science near the town of Troyan. The entire program of research and development for grassland maintenance and farming is concentrated there.
With the exception of some local beef farms, cattle are raised without using free pastures. Grassland farming is more typical for in raising sheep and goats. The breeding of other species - mostly fowl and pigs - is concentrated in large breeding units close to the larger cities. Fifty-nine percent of the pigs and 40% of the fowl are bred on such farms.
Structure and Numbers of Livestock
Data on livestock numbers by species over the last 5-6 years are presented in Table 1. The major decline in livestock numbers during the last two years is due to the ongoing process of land restitution and reorganization. For example, the total number of cows has recently declined about 22%, although their number in the private sector had increased 52% by the end of 1992. The trend is similar for other farm animals.
Table 1. Total number of farm animals in Bulgaria by 1 October 1992
Animal species Total Total compared to 1987 total (%) Female animals of reproductive age Cattle 1,113,949 -33.9 526,980 Sheep 5,079,938 -76.1 3,821,094 Swine 3,214,339 -37.5 283,393 Goats 599,836 +22.0 470,424 Water buffalo 23,273 -17.2 12,626 Poultry 24,198,600 -51.4 10,291,150 Genetic Resources of Livestock
Efforts to conserve the genetic resources of local breeds involve primarily state-owned farms and experimental research stations. Concern about the preservation and development of these breeds led to the establishment of the National Service for Selection and Reproduction in Animal Breeding (NSSRAB), supervised by the Ministry of Agriculture. This state unit has branches in all major regions of the country. It includes six stations for artificial insemination, located in Sofia, Sliven, Varna, Veliko Turnovo, Shoumen, and Pleven.
Indigenous Cattle Breeds
The Grey Iskar and Rhodope Short-Horned are of interest among cattle breeds for some unique genotypes that have been discovered by researchers. The Grey Stepland is an indigenous cattle breed that has spread to neighboring Balkan countries.
The Rhodope Short-Horned is the smallest representative of this species in Europe. These animals are descended from the craniological type Bos Taurus Brachiceros. However, some particular characters indicate that it closer to peat cattle than to cultured brachiceros breeds. This breed represents the last remnants of the prehistoric cattle in Europe. Along with the Albanian, South-Montenegrian, Ilirian, and Georgian Brachiceros cattle, it originated in Asia.
The Rhodope Short-Horned is distributed throughout the western and middle Rhodope Mountains, and also in the southern and eastern Rhodopes. These are forest lands 1800 m above sea level. The animals are small and their height at withers is about 97 cm. The coat color of this breed varies from light to dark brown; some can even be found with black coats. The horns are thin, soft, and crumbly, pale with dark tips, and about 15 cm in length. The hooves are dark and strong. Body weight varies between 160 and 220 kilograms. Newborn calves weigh 14.6 kilograms on average. The milk yield of cows is between 966 and 1133 liters with 4.5 to 4.6% fat (34, 27). The animals are not particular about farming and feeding conditions. In the summertime they feed on grasslands and in winter mostly on hay and forest-leaf forage (35).
Table 2. Total number of cattle in aboriginal breeds by 1 January 1993
Breed Area of distribution Number Ownership Grey Iskar cattle Dragana
Troyan
Shumen
Chiflika75
6
30
20Private sector
State sector
State sector
State sectorTotal Grey Iskar 131 Grey cattle Grudovo
Studena, Svilengrad
Ustrem30
50
100
50State farm
State farm
State farm
Private sectorTotal Grey cattle 230 Rhodope short-horn cattle Khamzovo, Smolyan
Smolyan80
70State sector
State sectorTotal Rhodope short-horn cattle 150 Total number of aboriginal cattle 511 Genetic research on transferrin and erythrocytic antigens (Table 3) (6, 7) shows that the frequencies of transferrin types Tf A and Tf D of this breed are close to those of the Brown Brachiceros breeds in Germany and Switzerland. In addition, the very rare transferrin allele Tf F has been discovered in this breed. This allele is found in almost no European cattle breeds, but is found, though rarely, in local Asian and African strains. The presence of the Tf F allele allows us to confirm the hypothesis of other researchers (4) that this breed originated in Asia.
The Grey Iskar is a local cattle breed related to the Grey Stepland breed, which has spread to other parts of Europe. The craniological class of animals of this breed is between Bos T. Primigenius and Bos T. Brachyceros, which distinguishes it from the Grey Stepland (6). Traditionally the Grey Iskar Cattle was distributed in north-central Bulgaria, by the Iskar, Vit, Osam, Skat, and Rositsa River valleys (35). At present, the limited number of animals of this breed are located mainly near the town of Sevlievo. A few are kept on private farms. The coat of the Grey Iskar breed is grey of different shades. The muffles and eyelids are black. Horns are U-shaped, pale with black tips. The body is proportion-ate, with strong legs. Its height at withers is about 115-120 cm. Its body weight is between 300 and 350 kilograms. Calves at birth weigh about 20-22 kilograms. The average milk yield is 1200-1300 liters with 4.1 to 4.2% fat. In herds with better farming conditions, milk yields may reach 1947-2648.9 liters (39, 24, 35). The length of the lactation period is 256-282 days. Animals of this breed show resistance to unfavorable climatic conditions and diseases.
The Grey Iskar breed has been an object of genetic research on different blood serum components: albu-mins, transferines, hemoglobin, amylase, etc. Some of the more interesting results are presented in Tables 4, 5, 6, and 7. The hemoglobin alleles in this breed differ significantly from the widespread European cultivated breeds, with very low values of Hb B allele frequency (9, 36). The presence of Akp D allele is rare, and has attracted the interest of geneticists. In analyzing these results, it is worth noting that, as with the Rhodope Short-Horned, the transferrin allele Tf F is found in the Grey Iskar breed. These studies prove the unique genetic status of the breed when compared to other European cattle breeds.
Table 3. Transferrin allele frequency in the Rhodope short-horn cattle
Number of test animals Allele frequency Reference Tf A Tf D Tf E Tf F Tf B 124 0.230 0.710 0.046 0.020 - Makaveev, 1966 Table 4. Albumin allele frequency in the Grey Iskar cattle
Number of test animals Allele frequency Reference Alb A Alb B 184 0.636 0.364 Makaveev, 1980 Table 5. Hemoglobin allele frequency in the Grey Iskar cattle
Number of test animals Allele frequency Reference Hb A Hb B 275 0.984 0.016 Makaveev, 1970 189 - 0.071 Makaveev, 198 Table 6. Alkaline phosphatase allele frequency in the Grey Iskar cattle
Number of test animals Allele frequency Reference Akp F Akp S Akp D 190 0.161 0.818 0.021 Makaveev, 1980 Table 7. Transferrin allele frequency in the Grey Iskar cattle
Number of test animals Allele frequency Reference Tf A Tf D Tf E Tf F Tf B 215 0.404 0.448 0.146 - Makaveev, 1965 373 0.417 0.458 0.115 0.010 - Makaveev, 1970 Indigenous Sheep Breeds
In numbers and diversity, the local indigenous sheep breeds and strains in Bulgaria significantly exceed other farm animal species (Tables 8 and 9). In contrast with cattle, sheep breeds are distributed throughout the many different districts of the country - in lowlands, semi- mountainous, and mountainous regions. Some of the breeds (e.g., Pleven Black-Face and Sakarska), although valuable as a specific genetic resource, will not be described in detail, since they are not threatened with extinction.
Indigenous Sheep Breeds in Lowlands and Semi-Mountainous Areas
The Karnobatska sheep breed is a local strain of the Red-Brown sheep that has been bred in Eastern Bulgaria for ages. It is supposed that this breed's origins have much in common with those of the Tzigay sheep and Asia Minor sheep breeds (33). At present there are 650 Karnobatska ewes bred on a state-owned farm.
The animals of this breed are small and compact, with well built bodies. Rams have heavy, whorled horns, while ewes are polled. Their fleece is mostly red and brown and very rarely pale. Their height is 50-55 cm, their length about 60 cm. The body weight of ewes averages 31 kg, of rams 38-40 kg. The body weight of newborn lambs is about 3 kg. Karnobatska is a dual-purpose breed, with equal emphasis placed on its production of meat and wool. The meat possesses good eating qualities, since it is fattened only on open grazing lands. Fleece weight is about 2.4 kg, exceeding all other indigenous sheep breeds in the country. Staple length is 18 cm. Average milk yield per ewe varies between 40 and 50 liters for 150 days of lactation. Milk fat is 8.4-8.97%; casein - 3.98%; lactose - 5.47%. Studies of hemoglobin alleles show that animals of this breed have the very rare allele Hb A with a frequency of 0.07 (9).
The Copper-Red Shoumen breed is distributed mainly in northeastern Bulgaria in regions with moderate continental climate conditions from 0 to 800 m above sea level. Representatives of this breed are medium-to-large, with an average body weight of 43-45 kg. Their bodies are compact, with an average height of 59 cm and length of 64 cm (3, 31). The fleece is rusty-red, though individuals with black coats can be found. Ewes are polled, rams have twisted horns. They usually have a well covered body and legs free of wool. Twining rate is about 25-30%. The milk yield per lactation period is 48 liters on average, with 7.32% fat. Wool production per ewe is about 2.6 kg (16). The results of polymorphic analyses of blood serum proteins are shown in Table 10 (12, 13). The presence of some alleles - Tf G, Alb F, Alb S, Alb W - is rare compared to the available allele pool in the Balkans.
The Starozagorska breed is the most typical of the indigenous sheep bred in the Bulgarian lowlands. It is found in valleys around the city of Stara Zagora, peculiar for their moderate continental climatic conditions. It is supposed that the breed developed by crossing Tzigay and Zackel sheep. The animals are large; the body weight of mature ewes is up to 60-70 kg. The weaning weight of lambs is 4.3 kg. The height is 64-65 cm, the length about 70 cm. The fleece is white. Sheep of this breed have an elongated head, sagging ears, long neck, and levelled back. The face, belly, and legs are free of wool (31). Milk yield is 165 liters, with 6.09% fat and 5.92% proteins (2). Wool production is about 3.7 kg (31). Due to its high productivity and adaptability to local conditions, the Starozagorska breed is used to improve crosses with cultivated sheep breeds. Genetic research (22) indicates the presence of the rare hemoglobin allele Hb A at a high frequency of 0.470.
Table 8. Productive lines in sheep-breeding according to the number of animals
Productive line Relative share (%) Thin-fleece 43.5 Semithin-fleece 18.1 Tsigai 23.4 Milk 13.4 Meat 0.2 Aboriginal breeds 1.3 Table 9. Number of sheep of aboriginal breeds by 1 January 1993
Breed Area of Distribution Number Ownership 1 2 3 4 Black-head Plevenska Pleven
Pleven
Dobrich
Russe
Sliven
Stara Zagora
Vratsa10300
6000
800
700
500
500
9000Public sector
Private sector
Public sector
Public sector
Public sector
Public sector
Public sectorTotal Black-head Plevenska 27800 Karakachanska 12 Lovech
Smolyan
Sofia
Shumen450
200
200
140Total Karakachanska 12 990 Starozagorska 3 Stara Zagora 1200 Public sector Sakarska 15 Stara Zagora, Haskovo 2400 Public sector Kotlenska 8 Sliven
Kotel680
300Private sector
Private sectorTotal Kotlenska 8 980 Replyanska 11 Vidin
Michailovgrad1300
1600Public sector
Private sectorTotal Replyanska 11 2900 Copper-red Shumenska 2 Shumen 430 Private sector Bresnishka 7 Bresnik 490 Private sector Marishka 4 Plovdiv 350 Private sector Dabenska 6 Plovdiv 370 Public sector Svishtovska 5 Svishtov
Pleven240
200Private sector
Private sectorTotal Svishtovska 5 440 Karnobatska 1 Karnobat 650 Public sector Strandjanska 9 Sliven 750 Public sector Tetevenska 13 Teteven 450 Private sector Staroplaninska 14 Pleven district
Sofia district800
600Private sector
Private sectorTotal Staroplaninska 14 1400 Srednogorska 10 Pirdop, Koprivshtitsa 920 Private sector Total number of aboriginal sheep 42680 The Marishka breed is found mainly on private farms by the valley of the Maritsa River near the cities of Plovdiv and Pazardzhik. Three hundred and fifty individuals of this breed are registered. They are multipurpose animals, with an emphasis on meat, wool, and milk. Average milk yield per lactation is 120 liters. The wool is semi-coarse, white, levelled, and lustrous. Average fleece weight is about 2.4-2.8 kg. Sheep of this breed are large, long-legged, and light-shouldered with a long body, light bone system, and strong hooves. Rams and ewes are polled. Ears are large and sagging. Their height is about 65 cm. Average body weight is 40 kg. Twining rate varies between 16 and 30% (37, 31).
The Svishtovska breed is found mainly on private farms located in the lowlands between the rivers Danube, Yantra, and Osam. A moderate continental climate is typical for these regions. According to some studies (30), this breed is an intermediate strain between the Tzigay and Zackel breeds. The Svishtovska sheep is one of the largest indigenous breeds in Bulgaria. Animals are 68 cm high and 70 cm long. Body weight is 42-44 kg. The body is well covered with white wool. Very often the face, poll, ears, and legs are black or spotted. The animals have strong muscular body constitu-tion and are resistant to hard climatic and feeding conditions. Milk yield is comparatively high: 90-100 liters with 8.2% fat. Fleece weight ranges up to 2.7 kg. Ewes mature early and lambs gain weight rapidly.
The Dabenska sheep breed is found throughout the lands around the town of Karlovo. At present this breed numbers 370 animals, bred on a state-owned farm. The animals are large: 65-67 cm high and 68-70 cm long. Body weight is 40 kg (20). The body is well covered with wool. This sheep is typically long in the tail. Ewes mature late, while lambs gain weight slowly. The wool is semi-coarse and well levelled. Fleece weight is 2.5 kg. Milk yield is high - 94 liters (20). Results of blood polymorphic analyses are presented in Table 10 (23, 10).
The Breznishka sheep numbers about 500. It is bred on private farms near the towns of Breznik, Radomir, and Tran. Animals are medium-to-large with black spots around the eyes and nose. Legs are white, black, or spotted, and the tail is long. Ewes are polled, while rams are sometimes horned. Average body weight is 40 kg, and height 60 cm. Milk yield of ewes is about 110-150 liters. Fleece weight is 2.0-2.6 kg and the wool is semi-coarse. Results of blood polymorphic analyses are shown in Table 10 (1).
The Kotlenska sheep breed is found in the semi- mountainous regions of the eastern Stara Planina. Animals are medium-to-large with strong bodies. The body is well covered with wool, which is relatively short but well levelled and milder than in mountainous sheep breeds. Wool production is 2.3-3.0 kg. Milk yield is low: 40 liters per lactation. Individuals of this breed are very adaptable. The Kotlenska breed differs from other sheep breeds located on the Balkan Peninsula by the frequency of some alleles of the transferrin and albumin polymorphic systems (11, 13). This breed is a carrier of some very rare alleles: albumin Alb T and transferrin Tf
Indigenous Sheep Breeds in Mountainous Areas
The Strandzhanska sheep breed is found throughout the highlands of Strandzha mountain. Animals are very well adapted to local conditions and more resistant to the piroplasmosis disease than other breeds in the region. Individuals are among the smallest in the country, having a body weight of about 30 kg. Height is 50-54 cm. Lambing weight is 3.0-3.5 kg. Twining rate is very low. The wool is coarse and fleece weight is 2.1 kg (38). Purebred animals are raised on state farms in the Sliven region. The valuable genetic resources of the Strand-zhanska breed are often used in crosses with other sheep breeds in the region in order to improve their adaptabil-ity and endurance.
Table 10. Polymorphous erythrocytic enzyme and protein systems and allele frequencies
System Allele Allele frequency by breed Copper-red Shumenska Bresnishka Kotlenska Dabenska 1 2 3 4 5 6 Hemoglobin Hb A
Hb B0.354
0.6460.209
0.7910.149
0.8510.117
0.823Catalase Cat F
Cat S
0.8230.211
0.7890.583
0.413Diaphorase - 1 Dia 1A
Dia 1B
0.4130.546
0.4540.598
0.413Diaphorase -2 Dia 2A
Dia 2B
0.4130.587
0.4130.404
0.596Carboanhydrase Ca F
Ca S
0.5960.014
0.986-
1.000X - protein X A
X a
X X
X x
0.285
0.7150.258
0.742
0.211
0.789Alkaline phosphatase Akp B
Akp O0.442
0.558Glutathione GSH H
GSH R0.474
0.526Albumin Alb F
Alb S
Alb V
Alb W
Alb T0.010
0.051
0.909
0.030
--
-
0.848
0.130
0.022Transferrins Tf E
Tf A
Tf B
Tf C
Tf D
Tf M
Tf G-
0.091
0.212
0.551
0.010
0.015
0.1210.016
0.221
0.284
0.337
0.079
0.005
0.0580.016
0.199
0.309
0.111
0.365
-
-The Srednogorska sheep breed is raised by private farmers on the slopes of the Sredna Gora and Stara Planina Mountains near the town of Pirdop. This is a small sheep breed, with a body weight of 35-38 kg. Body height is 60-65 cm and body length 59-62 cm. Animals have compact, well built bodies. Ewes are polled, rams have nicely whorled horns. Lambing weight is about 3 kg. Over 70% of the population has pale wool containing some red fibers. The face, ears, and legs are usually black. Individuals with white, red-spotted wool occur rarely. Wool is mild and fine compared to other indigenous breeds, but with very low fleece weight (1.3 kg). Milk yield of ewes is 45-47 liters with 8.09% fat. Fertility is low - about 90-100% - although ewes have unusual maternal abilities (37, 31).
The Replyanska sheep is typical of the coarse wool breeds. It is found in the western part of the Stara Planina Mountains. The Replyanska breed is relatively small with a compact and vigorous body. Extremely tenacious animals, they are very well adapted to mountainous farming and feeding conditions. Body weight is 34 kg on average. Height is 58 cm and length about 65 cm. Over 95% of the animals have white fleece. The whole body, including the belly and legs, is well covered with wool. The wool is coarse, with varying qualities. Fleece weight is about 2.0-2.2 kg. Milk yield is 90-100 liters per lactation. Results of studies of the polymorphic erythrocyte enzyme and protein systems are shown in Table 11 (1).
The Karakachanska sheep breed is found throughout the mountainous areas of Bulgaria. The number of purebred individuals of the indigenous Karakachanska sheep breed is very small. In different parts of the country there are larger numbers of crosses with other breeds. In the past the breed was one of the most wide-spread in the Balkans. Animals are small, vigorous, strong-boned, and short-legged, lively, and resistant to unfavorable climatic and feeding conditions and diseases. Hooves are hard. Rams have long, heavy whorled horns. The head profile is bowed. Face, ears, legs, and nose are black. The greater part of the population has pigmented wool - grey-to-black, sometimes brown. Wool is predominantly coarse. Fleece weight is 1.5-2.5 kg. Body weight of the ewes is 25-30 kg; of the rams 40-45 kg. Body height of the animals is about 57 cm. Body length is 62-69 cm. Belly, legs, poll, and face are covered with wool. Milk yield is 40-55 liters with 6.5- 8.0% fat. The allele frequency of some polymorphic systems of Karakachanska sheep breed are presented in Table 11 (1, 8).
Indigenous Pig Breeds
The Eastern-Balkan (Iztochno-Balkanska) pig breed is located in the mountainous areas of eastern Bulgaria. It belongs to the group of small European primitive pig breeds with short pricked ears. This local breed originated from the domesticated European pig (Sus Skrofa Domestica). At later stages in its development this breed was obviously influenced by Asian pig breeds (Sus Skrofa Palustris Rutt) as well. Proof of this hypothesis lies in the short legs and levelled back of the individuals (32).
These pigs are raised in herds in the forests. The basic food are pannages. Animals are virtually free of diseases and can reach 15-16 years of age. Anatomically the pigs of this breed are similar to wild boars. The head is very big with elongated muzzle, having a slightly bowed nose and short strong frontal bones. The profile length of the skull is about 31.5 cm and the width of the frontlet is 9.8 cm. There are 7 cervical vertebrae, 14 thoracic (with 14 pairs ribs), 5 lumbar, 4 sacral, and small knitted caudal vertebrae. Animals are of medium size. At the age of 3 years carcass length is 110-120 cm and height is 70-80 cm. Within the natural environment its body reaches its maximal weight of 80-120 kg weight at age three. Occasionally one finds animals as large as 180 kg in body weight. The body is compact, with heavy strong shoulders, short neck, slightly bowed up back, and a skewed rump. The coat is sleek over the whole body. Under stress, it will raise hard bristles on its back. Ears are short, pricked, and move easily.
The most prevalent coat color is black (which is dominant), but there are individuals with spotted, and very rarely white, coats. Sows farrow twice per year. The gestation period is 112 days. Average litter size is 4 to 7 piglets, but sometimes reaches 10. Sows have unusual maternal abilities. The suckling period lasts about 3 months. In terms of meat production capacity, the pigs of the Eastern Balkan breed defer to those of the contemporary cultivated breeds. Slaughter analyses show significant contents of intra-muscular fat and low (32%) carcass meat yields.
Investigations of stress resistance using the Hallotane test (21) showed that only 7.2% of the treated group had a positive reaction. This provides evidence for the claim that pigs of this breed have extraordinary adaptive abilities. Research on blood group antigen composition has shown a significant difference when compared with other pig breeds. In this breed one can find two very rare blood group antigens - Bb and Lf (5). Other studies (28, 14) confirm that the Eastern Balkan pig differs from other big breeds in its transferrines, amylase, 6-phosphogluconate dehydrogenase and phosphohexisomerase. One study (6) discusses the discovery of phosphohexisomerase allele PHI C, on the basis of which the presence of genotype AC - not common in any other pig breed - is determined. These results are confirmed in another work (15) that also indicates that there are two unique genotypes of this breed: AC and AB. All of these studies prove that the Eastern-Balkan pig is unique in terms of genetic diversity and is of extraordinary interest for preserving as a valuable genetic resource.
Table 11. Polymorphous erythrocytic enzyme and protein systems and allele frequencies
System Allele Allele frequency by breed Replyanska Staroplaninska Karakachanska 1 2 3 4 5 Hemoglobin Hb A
Hb B0.400
0.6000.208
0.7920.202
0.798Catalase Cat F
Cat S0.323
0.6770.329
0.6710.360
0.640Acid phosphatase Acp A
Acp B0.414
0.5860.657
0.3430.548
0.452Diaphorase - 1 Dia 1A
Dia 1B0.786
0.2140.517
0.4830.615
0.385Diaphorase - 2 Dia 2A
Dia 2B0.432
0.5680.347
0.6530.245
0.755Carboanhydrase Ca F
Ca S0.005
0.995-
1.0000.014
0.986X - protein XA
Xa0.390
0.6100.308
0.6920.337
0.663Arlysterase EsA +
EsA -0.130
0.870Alkaline phosphatase Akp B
Akp O0.293
0.707Albumin Alb A
Alb B
Alb C
Alb D0.020
0.030
0.740
0.210Transferrins Tf A
Tf B
Tf C
Tf D
Tf E0.200
0.110
0.180
0.460
0.050Indigenous Local Buffalo Breeds
The Bulgarian Mediterranean Buffalo is a local breed. It origins can be traced to the Wild Asian Buffalo (Bubalos Arnee). There are over 23,000 buffaloes spread throughout the lowlands of southern and northern Bulgaria. The present population was developed by crossing the local Mediterranean breed with breeds imported from the Indian subcontinent. As a consequence the number of purebred animals of the local buffalo breed is limited to 1 or 2% of the whole population. Small herds are bred in some state farms near the town of Shoumen, while larger ones are raised in the private sector, mostly in the northern part of the country.
The Bulgarian buffalo is a large animal, 570 kg in body weight, with strong bone structure and well developed muscularity. Its height at withers is about 130 cm. The coat is black or brown-black. Its horns are long, heavy, and grey-black in color. The age of first calving of buffalo heifers is about 36-38 months. Pregnancy lasts 315 days (58). Calving weight is about 34 kg. Milk yield is between 1500 and 1700 liters with 7.4-7.7% fat (3, 19, 17). Lactation period is 263 days.
Research on the characteristics of buffalo milk were carried out in the immediate aftermath of the Chernobyl disaster in 1986-1987. Compared to the other treated milks (dairy cattle, sheep, and goat), buffalo milk was found to have had the lowest rate of radioactive contamination (519 Bq/l). These studies also showed that buffalo milk had the lowest content of such radionucleotides as Iodine 131, Cesium 137, and Cesium 134 (3).
Conclusions and Possibilities for the Protection and Utilization of the Local Indigenous Livestock Breeds in Bulgaria
In conclusion, it is worth emphasizing again the large variety of genetically valuable local livestock breeds in Bulgaria. Some belong to rare genotypes that are increasingly important resources in the effort to preserve genetic diversity within different populations of farm animals. One way to preserve this precious genetic resource is to design and apply a program for the development and improvement of small populations of farm animals and for the promotion of gene banks. There are some ex situ programs that emphasize deep freezing of semen and embryos. This has been applied mainly in breeding cattle and buffalo breeding, and is practiced for the most part in the Research Institutes where the necessary equipment and experts are available.
Most of the local indigenous animal breeds are under the control of the National Service for Selection and Reproduction in Animal Breeding (NSSRAB). Although such animals are bred mainly on state-owned farms, the problems involved in protecting local breeds often stem from the fact that some of them belong to private farmers.
Preservation is also becoming complicated by the fact that these animals have lower productive capacities than the cultivated breeds, which makes raising them less competitive. In this situation, reasonable financial support and preferences for the private owners of local breeds will be indispensable. The need for such support is even more pronounced due to the fact that much of this livestock is located in the so-called "hard" regions in the mountainous parts of the country.
By preserving the genetic resources of the indigenous local breeds of farm animals, we will retain options for future use of their valuable adaptations in developing animal husbandry suited to these ecologically distinct regions of Bulgaria.
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