<<< 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 (Ñèíñêàÿ,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 (Âàâèëîâ, 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 (Âàâèëîâ,
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 (Âàâèëîâ,
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
(Ñèíñêàÿ, 1969), Zhukovsky
(Æóêîâñêèé, 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; Áðåæíåâ
and Êîðîâèíà, 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
(Âàâèëîâ,
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 (Âàâèëîâ, 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 (Âàâèëîâ, 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 (Âàâèëîâ, 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 (Êîìàðîâ, 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
(Âàâèëîâ, 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 (Âàâèëîâ, 1965a, Àãàåâ, 1987, Êîðîâèíà, 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. (Âàâèëîâ, 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 (Âàâèëîâ, 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 (Ãîâîðîâ, 1937; Ìàêàøåâà, 1979), mung bean (Ïîïîâà, 1937), soybean (Êîðñàêîâ, 1971, Òåïëÿêîâà, 1997), chickpea (Ñåôåðîâà, 1997), and vetch (Ñòàíêåâè÷, Ðåïüåâ, 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
Previous Page Main Page Next Page
All materials of the book are here!