DROUGHT TOLERANCE OF WHEAT INTROGRESSIVE FORMS

Abstract

In Kazakhstan the main limited factor for the wheat, growing up in arid lands is survival in the
summer, which make the studies on wheat drought resistance are very importance. It is interesting for
adaptation to environmental drought to be combined physiological and biochemical indicators with
total grain yield and productivity of wheat. The objects of the study were 12 introgressive forms of winter
wheat, obtained from the crossbreeding of the varieties of winter wheat (Triticum aestivum L.) with
wild relatives – Triticum timopheevii, Triticum militinae, Triticum kiharae, Aegilops cylindrical, Aegilops
triaristata, in the yield of 2015-2017.The drought tolerance of wheat genotypes in field experiments was
judged by the absolute value of yield and the signs of productivity, as well as by the degree of decline
in productivity under conditions of drought. Determination of drought tolerance in the laboratory was
conducted by the detection of free proline. Phenotyping, determine biomass accumulation and photosynthesis
was carried out on NDVI-technology. The experimental data were processed statistically and
by cluster analysis.
Screening of the results allowed to: reveal wide variability of the studied indicators; detect a change
in the standardized index of vegetation differences, determined by the accumulation of vegetative biomass
and phenological development phases of the studied wheat forms as well as obtained the best
genotypes with the maximum of the NDVI indexes. The genotypes promising in breeding for drought
resistance that persistently retain a high level of free proline content have been identified. There were
comparative analysis of the introgressive forms and varieties by total yield, identification of promising
simples by individual indicators and overall productivity. The results contribute to deciphering physiological
mechanisms of growth and resistance of grain crops, intensification of wheat breeding for adaptability
to environmental stresses, and enrichment of the genetic resources of Kazakh wheat with a variety
of prospective forms obtained from crossbreeding with wild relatives.