Schriften zu Genetischen Ressourcen - Genres

T. SMEKALOVA
the proponents of polytypic (“the species is a system”, VAVILOV 1931) and monotypic
(“the species is a geographic race”, KOMAROV 1940) species concepts.
Summarising this debate, TAKHTAJAN (1965) noted: “Now we are facing the necessity
of elaborating the intraspecific systematics of the most important plants of the flora of
the USSR.” Recent scientists mostly agree that “species can be defined as a complex
genetic system, however, with a common gene pool, protected from penetration
by genes from other species by biological isolation barriers” (YAKOVLEV and
AVERYANOV 1997). Nevertheless, this discussion has not yet been finished, and proponents
of both points of view can be found among Russian botanists.
When trying to trace the sources of this discussion, TAKHTAJAN (1965) noticed that
works on biosystematics, i.e., “differential systematists” in VAVILOV’s (1965) terms,
“dealt mainly with cultivated plants but also partly with their relatives”, while systematists
working on wild plants supported “small species”. The latter can partly be explained
not only by theoretical considerations (species as a geographic race), but
also by the feasibility of an inventory of a vast number of species in the USSR area
when writing the multi-volume work “Flora of the USSR” (1934-1957).
In fact, in the 1930-40s, VAVILOV and his co-workers assembled a vast amount of
plant material in the Institute of Plant Industry, namely, a living collection and a parallel
herbarium collection of cultivated plants and their wild relatives. The living collection
was subjected to complex detailed investigations both by the method of “geographical
sowings” in a network of experimental stations established all over the former
Soviet Union (cf. for example for barley, KNÜPFFER et al. 2003), and by many
different biological methods (cytological, genetical, physiological, anatomical, etc.).
“The investigation of cultivated plants for the purposes of breeding, as well as for
better comprehension of problems of their evolution, requires the application of differential
systematics. Breeders and agronomists have to distinguish not only species
but also varieties” (VAVILOV 1965).
On the one hand, VAVILOV interpreted the term differential systematics as a consideration
of the species as a complex of “geographical and ecological types” and subordinate
intraspecific taxa (VAVILOV 1931, 1965), which consists of “a discrete system
of hereditary forms”. On the other hand, he then writes: “We are now entering the era
of differential, ecological, physiological and genetical classification”, and interprets
“differential systematics” as the application of a complex of methods for the analysis
of intraspecific systems. TAKHTAJAN (1965) calls the “differential systematics” also
“biosystematics” and “experimental systematics”, which “summarises and synthesises”
results of other botanical and biological sciences.
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