<<< THEORETICAL BASIS OF OUR >>>
RESEARSHES
B.S. Kurlovich, S.I. Repyev and L.T. Kartuzova
Fig.1. N.I. Vavilov
Theoretically,
our research is founded on the works of Prof. N.I.Vavilov. Nikolai I. Vavilov (Fig.1) is recognized as the foremost
plant geographer, botanist and geneticist of this age. In the early 20th century, the world was yet unaware of the
urgent necessity to protect the environments, and scientists thought little
about gradual extinction of plant species. In fact, N.I. Vavilov
was the first who understood the imperative of intensive plant collecting,
studying and preservation, in spite of the hardest times he experienced in his
life. In order to explore the major agricultural regions over the world, Vavilov
organized and took part in over 100 collecting missions. During these
expeditions, he always focused special attention
on leguminous crops in general, and to lupin in
particular, regarding it as a source of protein and means of increasing of
soils fertility (Sinskaya,1991). He considered this problem as the highest priority in biological and
agricultural science and in the attempts to develop sustainable agricultural
production. Collecting activities of N.I. Vavilov
were started in 1916 with his foreign trip
to
In order to know the great
diversity of plants, they ought to be systematized and put in order. Therefore,
since the first years of its establishment and study, the plant collection has
been used as basic material for working out vital laws and regularities of
general biological nature, as well as theoretical fundamentals of plant breeding.
The concept of global genetic diversity of cultivated plants remained the
keystone of Vavilov"s work throughout his whole life. It incorporated a number
of major theoretical conclusions, which played an important role in the
development of botany, genetics and plant breeding. The law of homologous
series in hereditary variation, idea of the species as a system, differential
systematic and geographical method of crop research, botanical and geographical
aspects of breeding, and the theory of the centers of origin of cultivated
plants formed the core of these studies (Vavilov , 1920, 1926, 1935, 1940; Vavilov,
1997).
Vavilov"s theory of plant introduction was
developed on the basis of studying the earth"s vegetation. He identified a
number of areas distinguished by exceptional diversity and richness of plant
species and forms (Vavilov, 1965). Over 70 years ago (Vavilov, 1926), he
substantiated the selection of five ancient foci of origin of cultural plants from
local flora. Later (1935), he introduced additions and amendments to the
decoding of these foci and outlined 6 foci and 2 centers of origin of
cultivated plants. It is necessary to note that Vavilov always used to analyze
his works in a critical way, developing and deepening their main conclusions in
his subsequent publication. In 1940
(Vavilov, 1940), as well as in his Five Continents (published for the
first time in Russian in 1962, and translated in English in 1997), Vavilov
already named seven main primary centers of origin, placing foci within some of
them. The Indian and Indo-Malaysian focus earlier described by him was,
therefore, attributed to the South
Asiatic tropical center (1940), which in 1962 was renamed Tropical. The
.
I -
The Tropical center, II - The East Asiatic center, III - The Southwest Asiatic center, IV - The Mediterranean
center, V - Abyssinia, VI - The Central American center, VII - The Andean
center.
Within the limits of some of these centers, specific geographical foci were also distinguished. According to Vavilov, a center of origin of cultural flora is determined by two prerequisite conditions: abundance of plants suitable for domestication in the local flora, and availability of an ancient agricultural civilization.
The work on localization of the centers
and foci of origin of cultivated plants was continued by Sinskaya (Sinskaya,
1969), Zhukovsky (Zhukovsky, 1971), and other scientists from many
countries. Sinskaja (1969), in her
efforts to expand geographical connections and reciprocal interaction of
cultural florae, suggested a broader notion of a historical-geographic area.
She identified five areas and considerably updated the list of cultivated crops
in each area.
Among the supporters of the existence of
N.I. Vavilov"s centers there are many scientists from different countries
(Kurth, 1957; Harris, 1967; Harlan, 1971; Brezniev and Korovina, 1981; Mathon,1981). Some critics argue that it is very difficult to determine the very first geographical origin of a species. With this in view, they consider as more proper the term centers
of diversity in lieu of Vavilov"s
centers of origin . The term
centers of diversity is regarded as a safer one (Pistorius, 1997).
Thus, Vavilov"s
theory of the centers of origin or diversity of cultivated plants has
constantly been updated, improved, and even, in some respects, criticized, but
it is nevertheless still used as a theoretical basis for collecting, study and
utilization of crop genetic resources.
So far as lupin is concerned, Vavilov
considered the Mediterranean region and mountainous areas of
Any plant species when studied in a wide
range of geographical conditions, involving inbreeding, segregates into a wide
range of hereditary forms, which is difficult to comprehend at first sight.
Yet, in studying intraspecific diversity one can observe certain regularities
and reveal similarities in accordance with to N.I. Vavilov s law of homologous series in hereditary variation. The essence of this law may be described as
follows. Species and genera more or less closely related to each other manifest
similar series of variability lined up with such regularity that, knowing the
succession of varieties in one species, one could forecast the existence of
similar forms in other species or genera. The closer is the alliance between
the species or genera within the general system, the more complete is their
similarity in the series of variation. Whole plant families are in general
characterized by a definite cycle of variability, which goes similarly through
all genera and species of a given family. The laws discovered Vavilov help to put in order extensive materials of
cultivated and wild vegetation.
N.I. Vavilov marked out the congruity of variability in his description of the whole
family of Fabaceae Lindl.. Proceeding from the study of separate
genera within this family, he established the laws of their differentiation
into varieties observable in the sets of characters displayed in seed, fruit,
flowers, and vegetative organs. He provided detailed analysis of the
variability of characters in the representatives of sections Vicieae,
Trifolieae, Loteae, Galegae and Phaseoleae ( , 1920;
1987). It is clearly visible from his materials that, in spite of the
differences existing between the above-mentioned sections, they demonstrate
similar variability of characters, mandatory for all genera of the family.
Although he
presented no data as for the genus Lupinus L., subsequent investigations have shown, that Lupinus
illustrates Vavilov"s law of homologous series in variation even better than
any other genus of the Leguminosae family. Thus, conducting regular studies of the major lupin species one can
observe not only immense diversity in many thousands of plant forms, but also
parallel series even in pathological, mutagene and hybrid variability of a
given plant.
Let us meditate on only to a few of the
numerous examples. Describing
the materials supporting his law of homologous series in hereditary variation, Vavilov paid considerable attention to the
feature of plant color. Since various coloring of plants is an approved
hereditary character transferred from generation to generation, it was
introduced into systematic at a distinctive characteristic of separate species,
varieties, subvarieties and smaller taxonomic units. Presently available data
show that lupin has a correlation between the colors of seed, inflorescence, carina"s
edge, and vegetative parts. For example, white seeds of L. angustifolius
(from the eastern hemisphere) produce light green plantlets which later develop
light green or normal green foliage and begin to blossom in white flowers. From
pigmented seeds
it is possible to receive plants with dark green foliage and colored flowers.
With L. mutabilis (from the western hemisphere), white-seeded forms in
most cases also yield light green plantlets, subsequently forming green
foliage, and white, white-and-pink or white-and-blue flowers. However, even the
slightest pigmentation of seeds in L. mutabilis expressed only by a
small dark spot on the hilum results in formation of anthocyan shoots, dark
green foliage and dark blue or violet flowers. This is a common tendency in
variation for all lupin species as well as for other representatives of the Fabaceae
family. Nonetheless, not only parallelism in hereditary variation of
characters is obvious, but also there is affinity of setbacks in plant
development. These factors facilitate the task of making up intra - and
interspecific systematics of plants (Vavilov, 1935).
Combination of the coloring of seed,
vegetative parts, inflorescence and carina"s edge in various species of lupin
from both hemispheres, and complete parallelism in their age variability and in
morphological and biological characters doubtlessly witness to their genetic
closeness. Application of the above-mentioned laws allowed us to locate and
describe several new forms so far unknown in different lupin species, and
develop their intraspecific classification. The law of homologous series in
hereditary variation gives an answer to the question what material should be
looked for, while the theory of the centers
of origin of cultivated plants provides an answer to the question where it
could be found.
To
study intraspecific diversity and to determine the centers of origin of
cultivated plants, Vavilov and his followers used a differential systematic and
geographical method of crop studies (Vavilov, 1931), which meant as
follows:
differentiation of a genus into species and intraspecific
diversity with the help of morphological, hybridlogical, cytological and others
methods;
determination of the genotypic composition of a species;
geographical localization of hereditary forms of a species
as well as the centers of their diversity.
Of great theoretical and practical importance and subject to further
development is Vavilov"s concept of the species as a system (Vavilov, 1931,1965a). Previously, in the science prevailed
the notion of Acad. Komarov about monotypic species. According to it, the
species cannot include any systematic units of a lower rank (Komarov, 1931,1944). Also widely known was the concept of
biological species which postulated impossibility of crossing between species
(Grant, 1981,1984). Vavilov made a presentation of one of his fundamental
concepts "Linnaean Species as a System". Practical study of several
hundreds of species showed the absence of monotypic species, i.e. the species
represented by one certain race alone or a certain form alone. Each species
appeared to incorporate a larger or smaller number of forms (genotypes).
Vavilov regarded a species as a flexible isolated complex morpho-physiological
system linked in its genesis to a certain environment and area of distribution
(Vavilov, 1931, 1965a). The research on
several hundreds of cultivated species performed by a great number of
scientists according to a strictly regulated program lead him to the
understanding of the Linnaean species as a definite complex system, i.e. an
integrity consisting of closely interlinked components, where the whole and the
parts are merged with each other (Vavilov, 1965a, Agaev, 1987, Korovina, 1987). Therefore, in
the study of species on the basis of Vavilov"s theories (concept of the species
as a system, and differential systematic and geographical method of crop
studies) attention was focused not only on morphological characters, but also
on geographical and ecological differentiation and other properties of plants.
Such approach supported by the development of different intraspecific
classifications helped to accomplish profound and comprehensive analysis of
intraspecific and varietal diversity of cultivated plants, and find ways of
efficient utilization. In this respect, the International Code of botanical
nomenclature fixed such categories as subspecies (subspecies), varieties
(varietas), subvarieties (subvarietas) and form (forma).
Besides, Vavilov gave special heed to eco-geographical differentiation of the
species into ecotypes, geotypes, concultivars, etc. (Vavilov, 1931, 1965a). The postulate of the species as a
complex multilateral phenomenon would urge a researcher to use diverse methods
for identifying differences between intraspecific categories. In addition to
the main morphological method, the scientists of the Vavilov Institute have
widely used anatomic, cytological, caryological, paleobotanical, ontogenetic,
biochemical, physiological, geographical, genetic and other methods. Such
comprehensive approach is especially efficient when the intraspecific diversity
of cultivated lupin forms is concerned. This Vavilov"s differential systematic
and geographical method of crop studies is interconnected with other findings
of N.I. Vavilov and is based on his law of homologous series in hereditary
variation, his theory of the centers of origin (diversity) of cultivated
plants, and his concept of the species as a system (Vavilov, 1920, 1926, 1935, 1987b). All Vavilov"s fundamental
ideas interconnected among themselves and represent a complex doctrine about global
genetic diversity of cultivated plants. On the basis of this
doctrine, the experts of VIR have developed intraspecific classifications
practically for all leguminous crops, including peas (Govorov, 1937; Makasheva, 1979), mung bean (Popova, 1937), soybean (Korsakov, 1971, Tepliakova, 1997), chickpea (Seferova, 1997), and vetch (Stankevich, Repev, 1999). These
classifications make it possible to disclose completely the potential of
leguminous crops, and they are widely used in breeding practice and plant
science. We have also reviewed the system of Lupinus L. using Vavilov"s
concept of the species as a system, and applied his differential systematic and
geographical method in our studies. On this basis, we offer intraspecific and
eco-geographical classifications for three cultivated annual species of lupin (L.
albus L., L. luteus L. and L. angustifolius L.). This
approach provided a possibility to perform a targeted search of genetic
resources of lupins to solve problems of their evolution and selection. It
enabled us not only to cast light on the diversity of lupin forms, but also to
reveal a series of regularities in their variation depending on the degree of
cultivation, geographic environments and soil conditions. Such outcome, in its
turn, helped in finding and recommending valuable initial material for
breeding.
N.I. Vavilov laid a foundation of
the lupin collection in VIR. Valuable accessions of white lupin (Lupinus
albus L.) were collected by Vavilov during his trip to the
Not only did Vavilov collect and organize
studying of the assembled plant materials, but also he constantly strove to
improve methods of these studies. He took the initiative, in particular, to
develop a simpler and more widely accessible method of determining alkaloids in lupin. This effort of his
was inspired by the fact that the technique
of detecting and determination of lupin forms with low alkaloid content
elaborated in 1928-1929 by v. Sengbusch in
Fig.
3. N.I. Vavilov with his wife E.N. Barulina,
1926 (before their expedition to the
N.I. Vavilov symbolizes the glory of Russian and world science and, at
the same time, personifies its tragedy. In the stifling atmosphere of Stalin s totalitarian rule, the
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