Устойчивость культивируемых злаков к тлям

Abstract

The results of small grains and sorghum gene pool resistance to cereal aphids are discussed. Both major and minor genes for aphids resistance in cereals differentially interact with insects. Therefore, the most rational plant breeding provides for increasing genetic diversity of cultivated varieties. The possibilities of effective genes for resistance replenishment for account of cultivated cereals genetic resources study, introgression and mutant accessions development are discussed. The resistance of Triticum sp. to English grain aphid (Sitobion avenae) and bird cherry-oat aphid (Rhopalosiphum padi) has been studied in different regions of Russia and Uzbekistan. The genepool of bread and durum wheats is poor in resistant forms. Diploid species with genomes A (T. urartu, T. boeoticum, T. monococcum) are the most resistant. Possessing a D genome in the species T. kiharae and T. miguschovae gives high resistance. Resistance controlled by the G genome is overcome by the pests. On the other hand, only cultivated sorghum species had very effective resistance. Resistance to greenbug was studied in 5059 sorghum accessions and highly resistant lines were isolated. Genetic uniformity of the donors of resistance, widely used in the breeding programs of Russia and USA, has been revealed. The new genes for greenbug resistance in sorghum are identified which are offered for breeding practice. Our experiments revealed also that somaclonal variation can be used to increase genetic diversity for greenbug resistance in wheat and barley. We have found a high frequency of greenbug resistant accessions among barley, oat and sorghum landraces from Asian countries. The duration of resistance in cultivars neither to be related to its phenotypic manifestation nor the number of resistance genes.