The methodologies worked out by N.I.Vavilov and his associates for evaluating varieties in geographic experiments and for developing an agro-ecological crop classification helped to issue "Methodological guidance directories for studying the VIR's collections" (1973). Descriptor lists were developed for different crops. When the descriptor lists were issued, the Institute commenced the work on computerization of the collection of the passport data. At the same time, the Institute initiated to resume the publication of the "Reference catalogues" containing results of studies on certain genera and species for many years.

N.I.Vavilov's investigations in the sphere of phylogeny and genetics proper of cultivated plants have been continued. Results of these and other continuous studies of genetic potential of cultivated crops and their wild relatives have been processed by the VIR's researchers into volumes of the "Cultivated flora" and monographs devoted to separate crops. Many of them contain taxonomic descriptions of genera and species of cultivated plants and their wild relatives, updated or revised on the basis of new data on genetics, cytology and molecular biology. The publication of the Institute represent an encyclopedia of crop genetic resources. VIR sends the above publications to numerous research institutions within the USSR and to many foreign countries.

Following the major objective of developing N.I.Vavilov's concepts, fundamental research has been broadened, and the methodological work on genetics, physiology, immunity, biochemistry and molecular biology intensified at the Institute.

Investigations by Acad. V.F.Dorofeev (1972) resulted in determining that the focus of type-formation and evolution for Triticum was located in the Transcaucasus; Prof. R.A.Udachin proved N.I.Vavilov's thesis of coincidence in Middle Asia of the centres of origin, type-formation, and specific diversity of Triticum aestivum L. and T. compactum Host. He also described a new endemic species T. petropavlosky Udacz. et Migusch. Prof. A.I.Ivanov (1980) explored Middle Asia (Uzbekistan, Kirgizstan, Turkmenistan and Tajikistan) and Kazakhstan and found there large foci of introgressive hybridization in wild alfalfa, determined areas of distribution for the species with different ploidy, and described the geography of plant characters having value for breeding. Prof. N.K.Lemeshev (1992) identified foci of origin of wilt-resistant long-fibre forms of cotton in Yucatan province and other regions of Mexico. Intensive explorations in Western, Central and Southern parts of Africa resulted in identification by Prof. S.N.Bakhareva (1988) of two independent centres of origin and diversity of cultivated plants and their wild relatives: the West African and Central African centres.

Applying the botanico-geographical methods devised by N.I.Vavilov, the Department of Tuber Crops headed by Acad. S.M.Bukasov and Acad. K.Z.Budin studied the geography and phylogeny of South American potatoes, improved taxonomy of this important crop, identified a centre of the maximum specific diversity and centres of the most intensive type-formation, areas of concentration of the traits valuable for breeding.

Researchers from the Vegetable Crops Department (Boos et al, 1990; Sazonova et al., 1990) have specified centres of origin and intensive type-formation for cabbage, onion, beet, carrot, radish and melon. Hypotheses concerning the evolution of these crops have been made, and intraspecific taxonomy developed (Cultivated Flora, 1971, 1978, 1984, 1985, 1988, 1994).

Fruit experts (Vitkovsky, 1984) from the Institute studied the intraspecific polymorphism in separate crops, determined foci of maximum concentration of wild pomegranate, pistachio, almond, stone-fruit crops and grapes, specified altitude limits for fig and sour cherry, determined areas of distribution of arid plants, and carried out other research programs supporting and augmenting N.I.Vavilov's work (Cultivated Flora, 1983).

With the aim of summarizing the genetic potential of germplasm, the Institute began to publish a series of volumes on "Genetics of cultivated plants" in the 1980’s.-1990’s Four volumes have been published, namely "Wheat, barley, rye" (1986), "Maize, small grains, oats" (1988), "Legumes, vegetables, melon crops" (1990), "Flax, potato, carrot, leaves vegetables, gladiolus, apple, alfalfa" (1998).

In order to standardize the work with the collection and its computerization, special descriptors of the crops are developed and include the international descriptors of COMECON countries.

The studies of the preserved germplasm diversity performed in the field by the Departments of Plant Resources have been intimately connected with the research conducted by Fundamental Laboratories of VIR. For example, under the leadership of Professor V.I.Krivchenko, the Institute has been developing theoretical bases, methodological principles and techniques of fungus disease resistance diagnostics in various crop species, the system of assessment of the collection for disease resistance, resistance breeding strategies in different crops, the problems of genetic uniformity of crop plantings and their role in aggravating epiphytotics (Krivchenko, 1984).

The Institute’s scientific staff continued N.I.Vavilov’s works in studying the hereditary nature of the plant species on the rich biodiversity of VIR’s germplasm collections and succeeded in realizing his principles of practical utilization of the results of the research carried out by the Institute. Works (Merezhko, 1994b; Rigin, 1994; Mitrofanova, 1994) in genetics and comparative genetics of the major species of cultivated plants and their wild relatives are combined with solving evolution, taxonomic and breeding problems as well as meeting the demands of agricultural production. Such an approach made it possible to outline a fundamental pattern for genetic studies of plant germplasm for breeding purposes(Merezhko, 1984). It comprised the following phases:

1. Establishing collections of plant species according to the range of variation in characters;
2. Identifying genotypic differences in the studied characters between plant accessions;
3. Studying genetic control of plant characters and determining the number of potentially useful alleles to plant breeding;
4. Identification of the alleles;
5. Established characterized genetic collections.

Special methods were developed to determine the number of genes controlling minor quantitative characters (Merezhko, 1994c). These have helped in discovering new genes of value for breeding, develop methods to search for or create donors of such genes, and transfer them into the genotypes of commercialized cultivars. For the first time, genes for cytoplasmic sterility and a dominant form of dwarfness were discovered by Prof. V.D.Kobylyansky in rye, thus initiating new trends in rye and triticale breeding (Kobylyansky, 1982, 1994). A model of eco-genetic organization of complex quantitative characters has been formulated for the development of new efficient breeding technologies towards higher productivity, resistance and quality (Dragavtzev et al., 1995).

The Law of Homologous Series in Variation and the problem of species formulated by N.I.Vavilov have found reflection in the studies on molecular biology by Acad. V.G.Konarev. Genetics of the characters of intraspecific diversity is a high priority among other aspects of comprehensive study of plant genetic resources (Konarev et al., 1993). Storage proteins analyze was refined to solve genetic resources problems. These and other approaches have given a possibility of identifying the plant genome, realizing genomic analysis of allopolyploid species of cultivated plants and their relatives, evaluating the genomic relationship between species in polyploid complexes of wheat, potatoes, rice, cereal grasses and cruciferous species, discovering the ways of cultivated plant genome origin, to determine the degree of relationship and crossability between cultivated and wild species, and controlling genome reconstruction, polygenome composition, and introgressions in allopolyploid selection (Konarev, 1998; Konarev et al., 1996).

For various crops the Institute's scientists have studied the mechanisms of plant adaptation to stress, developed, modified and developed efficient screening methods.

Following N.I.Vavilov's concept of developing initial material for breeding, researchers of the Institute study plant genetic resources for characters possessing value for this purpose. As a result of primary evaluation, during 1990 and 1991 around 4,000 sources of useful to breeding characters were selected, and genetical studies revealed 77 sources, including 27 resistance to pathogens of wheat, barley, oats, peas, etc., 9 forms of early maturing for Russian condition of oats, maize and sunflower. Fifty-one new sources have been created. VIR specialists and breeders from the breeding centres are always in close contact, working together within the framework of the breeding programmes. Breeders come to VIR to get acquainted with new material obtained for the collection, while VIR researchers go to the breeding centres to study breeders's needs and requests for breeding material. In addition, special field workshops are organized at VIR experimental stations and breeders are invited to participate. At these workshops breeders get acquainted with new accessions in the field and decide together with the VIR specialists which of the accessions are more promising for breeding programmes. As a result of such cooperation, more than 60% of commercial varieties have been bred using material from the VIR world collection. In cereals, 95% of all cultivars bred in the recent period were based on germplasm stored in the collection of VIR. Using materials from VIR's collection the breeders of the USSR have developed over 2,500 cultivars of various agricultural crops. In the 1990’s many of them are commercially cultivated occupying over 60 million hectares (Sazonova et al., 1994). Collections of such important crops as wheat, barley, rye, oat, maize, pea, soya, potato, tomato, cucumber, apple, cherry, plum, strawberry, alfalfa, etc. have been used most intensively.

The comprehensive study and use of new initial material made it possible to considerably broaden breeding programs involving the major crops. Materials from the collections served as a basis for developing sunflower cultivars with high oil content; the first national heterotic hybrids of maize; potato cultivars possessing resistance to Phytophthora, aggressive biotypes of potato canker, and nematodes; high-yielding cultivars of cereals and vegetables. A new trend in breeding dwarf wheat and rye was started; wild cotton species have been used in breeding for caducousness in order to exclude pre-harvest defoliation, and to serve as sources of gossypol-free seed; tomato forms possessing genes necessary for creating cultivars and hybrids with an increased fruit keeping ability have been used; cytoplasmic male sterile lines of sugarbeet and other vegetable crops have been introduced into breeding programs.

Upon selecting appropriate sources, it became possible to start rice breeding for semi-dwarfness, of peas for leaflessness and non-shattering of pods, and of soya for resistance to nematode. On the basis of studies of the world plant diversity, researchers of the Institute have included new aspects in breeding; for example, nitrogen fixation ability when breeding leguminous crop cultivars of intensive type, resistance to mechanical damage in potato varieties. A new cereal crop, Triticale has been created and successfully introduced into cultivation by VIR specialists (Sazonova et al., 1994).

The number of publications summarizing results of studies of the collections has reduced. At the same time, preparation of the second edition of the "Theoretical bases of breeding" was started in 1990. In 1993 the volume entitled "Molecular biology aspects of applied botany, genetics and breeding", in 1994 another one, "Physiological aspects of applied botany, genetics and breeding" was published, and in 1995 - "The genbank and breeding of grain legumes" was prepared for the press. At present, new volume of Cultivated Flora devoted to soya is underway. Some reference catalogues with list of identified genes controling of main characters were published(Merezhko, 1994d, Loskutov et al., 1997).

Sufficient use of the world's plant genetic resources is linked with the success of plant breeding, thus keeping the priority in the list of the Institute's objectives for collecting of global plant genetic diversity.

From 1946 to 1965, the Institute carried out 130 collecting missions in various regions of the Soviet Union. With the objective of wide-scale and systematic exploration and collecting plant genetic resources in the USSR, in 1966 the Institute established collecting missions planning group: European, Caucasian, Kazakhstanian, Middle Asian, West Siberian and Far East ones, and since 1976, the East Siberian mission.

From 1966 to 1993, the Institute's scientists performed botanical and geographical surveying and collected plant germplasm from the territories stretching from the Kola Peninsula to the Black Sea Coast of the Caucasus, and from Belorussia to the Kurils. As a result, over 60,000 seed accessions and planting materials of agricultural crops and their wild relatives were added to the Institute's collection, while the herbarium was enlarged by approximately 100,000 specimens (Mesherov et al., 1981; Kobylyanskaya et al., 1990; Zoteeva et al., 1996).

Every year 30 to 40 collecting teams were annually engaged in collecting plant genetic resources in the USSR. A collecting trip usually lasted from 15 to 45 days. These missions had narrow specializations, each focusing on collecting species of Triticum, Aegilops, Hordeum, Linum, Pisum, fodder crops, vegetables, fruit trees, etc. As some of the collecting sites were far away and hard to reach, each group was staffed with specialists in various crops who were able to collect all plant materials to be found in the wild areas of a particular region. During explorations each collecting group gathered from 50 to 300 accessions and, if possible, herbaria specimens (Bakhareva, 1994).

The aggravated tension in international relations and other political troubles made it almost impossible for foreign scientists to carry out explorations and collecting in the USSR, as well as for Soviet scientists to conduct collecting missions abroad. Only in the early 1960's Soviet and American scientists established contacts in the sphere of joint collecting and studying plant genetic resources under the Soviet-American joint Commission for Cooperation in Agriculture with the Ministry of Agriculture of the USSR and USDA.

After the activities that had taken place in the 1980's, in the end of 80's VIR expanded bilateral cooperation with various genebanks and international organizations on collecting cultivated plants and their wild relatives. For such purposes VIR organized joint missions with foreign scientists over the territory of the former USSR. Most of these explorations were financially supported by the foreign participants (more see publication of IPGRI).

The germplasm collection of the N.I.Vavilov Institute was annually enlarged by 2,000-3,000 accessions collected within former the USSR. For example, 136 scientists participated in collecting missions in 1989; VIR specialists explored 59 areas of the country and collected 2,100 accessions.

The centres of origin described by N.I.Vavilov were not only visited by Soviet collecting missions. Collecting missions were also arranged by the United States, Australia, India, Italy, Japan, Germany and other countries. During the period from the first publication of N.I.Vavilov's concept of centres of origin and 1970 U.S. scientists carried out 101 collecting missions, 75 of which were sent to centres of origin. From 1967 to 1976 Australian scientists undertook 58 germplasm collecting trips, 45 of which explored the centres of origin of cultivated plants (Kobylyanskaya, 1989).

In 70-s COMECON member countries enhanced and systemized the exchange of plant genetic resources between them. The first decade of joint research brought positive results: national collections of the member countries were enlarged by nearly 200,000 accessions of various crops. The next step in the cooperation of the COMECON countries was the establishment of the Scientific and Technical Council (STC) on wild and cultivated plant collections with the membership of the collaborating institutes. Working conferences of specialists were also held on a yearly (in 70-s-80-s) basis with the purpose of solving individual problems, exchanging experience and discussing the jointly developed descriptors.

Joint expeditions were organized through out the territories of the USSR and East European countries and germplasm exchange was carried out systematically based on the requests of the countries.

From the middle of the 1970's, when VIR was most active in establishing an international plant genetic resources network, its germplasm collecting activities became ever wider. The Institute organized expeditions to all continents, thus recognizing N.I.Vavilov's instruction that explorations of the same territories, especially in the centres of crop origin where the process of plant type formation was most dynamic, should be performed every 5 or 10 years.

In Europe the Institute's scientists concentrated on the Mediterranean centre of origin and diversity of cultivated plants and their wild relatives. They also undertook trips to a number of countries in Western and Eastern Europe, where the level of breeding practice was high, with the purpose of obtaining new plant breeding materials and information on modern breeding trends.

In Asia the first collecting missions were sent to several countries. From Yemen, a unique region in the Arabian Peninsula, drought-resistant forms of wheat, barley, sorghum and African millet were brought to the collection and of practical value were extremely early forage grasses and drought-resistant samples of cowpea, lentil and beans. Aboriginal forms of various agricultural crops from Laos and Burma are also worth mentioning.

During these years the Institute continued the exploration of new areas in the African continent. From there, large collections of tropical plant species and genera were delivered to the Institute together with samples of traditional crops adapted to Africa and having traits of breeding value such as disease resistance, drought resistance, heat tolerance. In Zaire and Zambia, the native countries of some Sorghum and Gossypium species, drought-, disease- and pest- resistant landrace populations of small grain, industrial, leguminous, and vegetable plants were found. Drought-resistant wheat, barley and sorghum were obtained from Burundi and Tanzania as well as samples of early ripening maize, Pennisetum, Phaseolus beans and some other crops (Kobylyanskaya, 1989).

In South America, major collection missions were concentrated on the species originated in American centres, of diversity on cultivated and wild species of potato, maize, sunflower, cotton, tomato and other crops. VIR's scientists also made several trips to the U.S., Canada and Australia with a purpose of studying breeding practice and exchanging plant germplasm. Collecting in Australia yielded promising forage grasses capable of rapid growth after cutting, cotton cultivars characterized by uniform boll ripening, reistant forms of wheats and high-quality vegetable crop cultivars (Kobylyanskaya, 1989).

In each year the Institute organized collecting missions to between four to eight foreign countries, usually lasting 20 to 30 days on average. Participants in a collecting mission made thorough preparations for their collection work: they studied geography, climate, vegetation, as well as scientific information on plant industry, plant breeding, genetics and botany. They visited scientific institutions and local markets of that country as well as collecting plants in the wild. For immediate seed exchange, they brought 50 to 150 of the best commercialized varieties from the VIR collection with them.

When collections took place abroad, usually all crop species were collected rather than a specialized collection of a single crop.

VIR's collection was also enlarged through the exchange of samples. In 1989, 9,000 samples from the Institute's collection were sent to 46 countries, while VIR received 9,500 samples from 45 countries. For this purpose every three years the Institute published the seed exchange catalogue Delectus Seminum and received similar catalogues from the USSR botanical gardens and foreign institutions. The Vavilov Institute also satisfied all requests for plant samples in addition to those offered through the catalogue. New varieties of agricultural crops that had been commercialized in the previous two years were the only exceptions. They were not sent to foreign correspondents; other seeds were dispatched free of charge for scientific purposes only.

Nowadays the interest of the Institute's scientists to the centres of origin of cultivated plants has not diminished. These centres continue to be regarded as the foci of maximum concentration of diversity species and cultivars capable of supplying the agricultural and breeding practice with valuable plant traits and properties. The current strategy is to go on with a targeted search for such plant materials, adjusted with respect to the prospective programmes of development of the agricultural practice.

N.I.Vavilov held that the problem of new crops and enhanced use of wild plants both in this country and abroad was especially important. With this in view, the Institute has obtained and studied valuable plants previously unknown to the national agricultural science and practice.

Contents
Acknowledgements

Chapter 1. Initiation of collecting and studying plant genetic resources in Russia from 1894-1920.

1. Establishment and activities of the Bureau of Applied Botany before 1905.


2. The structure and reorganization of the Bureau in the years 1905-1920.


3. Objectives and tasks of the Bureau, 1905 -1920.

Chapter 2. Brief sketch of N.I.Vavilov’s life up to 1920.

1. Education in Moscow.
2. Studies abroad.
3. Activities between 1914 and 1920.
   • First collecting expeditions.
   • Saratov period.
   • Theoretical concepts of N.I.Vavilov researches - steps forward from De Candolle and Darwin.

Chapter 3. N. I.Vavilov as Director of the Institute of Plant Industry.

1. N.I.Vavilov’s initiatives in the Department of Applied Botany and Plant Breeding.
   • Travels in America and Europe.
   • Rebuilding the Department.
   • Geographically based studies of plant production.
2. N.I.Vavilov’s activities in the All-Union Institute.
   • The foundation of the Institute and the development of its work programme.
   • Genetical research.
   • Crop evolution and taxonomic work.
   • Fundamental publications.
   • Agro-ecological studies.
   • Plant introduction and crop improvement.
3. N.I.Vavilov as a prominent organizer of science in the USSR.
4. N.I.Vavilov and the Institute’s internal relationships, 1925-1938.
   • American visitors.
   • Visits by O.Frankel and others.
   • A visit by Jack G.Hawkes.
   • References of N.I.Vavilov’s activities

Chapter 4. Collecting missions and explorations, 1922 - 1940.

1. Afghanistan.
2. Transcaucasus and Turkey.
3. North Africa.
4. The Middle East.
5. Abyssinea and Eritrea.
6. The Mediterranean.
7. Spain.
8. The Far East.
9. The Americas.
10. Other travels.

Chapter 5. N.I.Vavilov’s theoretical contributions.

1. The law of homological series in hereditary variation.
2. Centres of origin.
3. Disease resistance.
4. Taxonomic studies.
5. Centres of agriculture.
6. Plant breeding .

Chapter 6. Activities associated with plant genetic resources in the 1930s and 1940s.

1. T.D.Lysenko’s role in the development of agricultural science in the USSR.
2. Collision of scientific concepts.
3. N.I.Vavilov’s arrest, imprisonment and death. Dismissal of the Institute’s leading researchers.
4. World War II. The siege of Leningrad and the resue of the collections.

Chapter 7. Developments N.I.Vavilov's theories on plant genetic resources.

1. New information on centres of origin and diversity.
2. The development and organization of VIR’s work.
3. Phylogeny and genetics.
4. Long term conservation.
5. Basic research.
6. Collecting missions in the 1940s and 1990s.
   • Expeditions within the former USSR..
   • Overseas collecting
     • 1950-s.
     • 1960-s.
     • 1970-s.
     • 1980 - 1990-s.
   • Organization of collecting and exchange.

Chapter 8. Creation of the network of genebanks in COMECON countries.

1. Establishement of the Scientific and Technical Council for colections of wild and cultivated plants (STC).
   • Organization and execution of joint collecting missions.
   • Joint field evaluation and use of plant genetic resources in plant breeding.
2. Establishment of genebanks in COMECON countries.
   • Bulgaria.
   • Hungary
   • East Germany.
   • Poland.
   • Czech Republic.
   • Romania.
   • Yugoslavia.
   • Mongolia.

Appendixes

List of mentioned names.
Major N.I.Vavilov's expeditions.
Map of N.I.Vavilov's expeditions.
Major collecting missions accomplished by N.I.Vavilov's associates.
Major species collected by N.I.Vavilov on his expeditions (1916-1940).
VIR's major expeditions within the former USSR in 1986-1990.
Major collecting missions to foreign countries accomplished by VIR's specialists (1954-1994).
Joint collecting missions of COMECON countries (1973-1990).
The list of the International COMECON List of Descriptors.

N.I.Vavilov and his institute

Table 1. Commercialized cultivars bred on the basis of VIR's collection.

Crops	Number of VIR's catalog	Name of VIR's accessions	Origin of VIR's accessions	Name of commercial cultivars	Acreage in the USSR, mln ha
Winter wheat	29759	Klein 33	Argentina	Bezostaya 1	10.000
Spring wheat	8085	Garnet	Canada	Skala	1.000
Barley	6829	Local	Turkey	Donetzkii 8	5.000
Oat	10247	Local Zensin	Russia, Sakhalin is.	Narymskii 943	1.000
Rye	10028	Local Nizkostebelnaya	Bulgaria	Chulpan	2.500
Corn	11081	Janetski's Gloria	Germany	Bukovinskii 3	2.000
Pea	5701	Priekulskii 349	Latvia	Neosypayushiisya 1	1.000
Alfalfa	29207	Local Slavyanskaya	Russia, Krasnoyarsk reg.	Kapchegaevskaya 80	0.100
Potato	2098	Cobler	USA	Priekulskii rannii	0.150
Tomato	3248	Barnaulskii	Russia, Western Siberia	Fakel	0.120
Apple	28720	Zhigulovskoe	Russia, Samara reg.	Malychenkovskoe	0.010

• European part of the USSR - includes Baltic Republics (Estonia, Latvia and Lithuania), Ukraine, Belorussia, Moldavia and European part of Russia.
• Caucasus - includes Georgia, Azerbaijan, Armenia and Caucasus part of Russia.
• Middle Asia - includes Uzbekistan, Tadjikistan, Turkmenistan and Kirgizstan.