Zbornik - Društvo genetičara Srbije

18 ZBORNIK ABSTRAKATA III KONGRESA GENETIÈARA SRBIJE I-Usm-7
Subotica, 30. novembar - 4. decembar 2004.
GLIADIN CODING GENES OF BREAD WHEAT AS GENETIC
MARKERS OF ADAPTABILITY OF CULTIVAR
Dragovich-Novoselskaya A.Yu.
Institute of General Genetics RAS, Moscow, Russia
Grain storage proteins of bread wheat Triticum aestivum, gliadins, separated by PAAG electrophoresis
are reliable genetic markers used in molecular, genetic and breeding research.
There are six unlinked gliadin-codin loci. A vast multiple allelism has been described at each
of these loci that permit high-precision identification of cultivar genotypes in terms of gliadin
allele composition. As was shown earlier gliadins can be used as genetic markers of bread
making quality, which means that they are linked to genes controlling valuable traits.
In this report we present results of the examined genetic diversity of bread wheat
cultivars, bred in the Saratov plant breeding center during more than last 80 years of the
scientific breeding programs. The aim of our study was to determine the genotypes most
adapted to agro-ecological conditions in the region.
In the early 20 th century Saratov scientific breeding was based on Poltavka, which was
local cultivar-population characterized by rather high intracultivar polymorphism (table.)
In the middle of 20 th century on the basis of Poltavka the best Saratov cultivars (e.g.
Saratovskaya 29) have been developed. About 62% of these cultivars carried biotype
gained from Poltavka (f.e.a.q.s.e.).
Loci/ alleles
Cultivars
Gli-A1 Gli-B1 Gli-D1 Gli-A2 Gli-B2 Gli-D2
Poltavka (1930s) o,f,c, j e, m a q o, s e, a
Poltavka (2003) f E a q s e
Cultivars (1950s). f,i E a q,s s,o, q e
Modern cultivars* f,i,m E a,k q,o, q,w,s, e
*6 new alleles have been found that had not been registered earlier in a catalogue. Bold letters denote
the main Poltavka biotype.
Modern Saratov cultivars, bred in the last decade, are more heterogeneous than the previous
group because of extensively involving alien genetic material. This group comprises 19
alleles, 6 out of them are new, gained from foreign cultivars-donors. Frequencies of these
new alleles have been increasing from year to year. However, the same Poltavka biotype
(f.e.a.q.s.e.) occurs in the group of modern cultivars constituting about 50% of all biotypes
(table). Nowadays, Poltavka which is no more used in breeding, has been grown as collection
pattern from the 1950s till now. This pattern has become a line carrying only one
biotype (f.e.a.q.s.e.), which is more frequent among different Saratov cultivar groups.
Probably, this elimination of other biotypes is caused by natural selection rather than the
absence of artificial selection (e.g. for bread-making). Apparently, high frequency of the
biotype in all the groups can be explained by the fact that definite multilocus combinations
marked by definite gliadin biotypes are selected for particular environment.
The genetic diversity in modern cultivars is twice as high as in the old ones (0.4 and 0.2,
respectively). Intracultivar polymorphism of modern cultivars is 2.2 times higher. Such
high heterogeneity may be attributed to the fact that the large number of genotypes increase
adaptation of cultivars comprising alien (non adaptive) genetic material.