Genetic diversity of barley accessions from Mongolia for greenbug resistance

Abstract

BACKGROUND: Significant damage to barley crops in the southern regions of the Russian Federation is caused by the greenbug Schizaphis graminum Rondani. Cultivation of resistant varieties is a cheap, efficient and environmentally friendly way to combat the phytophage. The specificity of relations between S. graminum and barley is shown, that determines the need to broad the genetic diversity of cultivated varieties.
 AIM: The study of effectiveness and genetic control of the greenbug resistance in barley accessions from Mongolia.
 MATERIALS AND METHODS: We studied 175 barley landraces from Mongolia for resistance to the Krasnodar aphid population. We assessed damage to resistant lines selected from heterogeneous accessions k-3885, k-3904, and k-4080, as well as the variety Post (a carrier of the previously identified Rsg1 gene) by 86 aphid clones isolated from the population. Under laboratory conditions, the aphid resistance segregation of F2 hybrids was analyzed from crossing three accessions from Mongolia with a susceptible tester.
 RESULTS: Five heterogeneous accessions were identified, in which plants with high resistance to the pest were found; in 28 accessions, damage to the leaf surface of the resistant component varied from 31% to 60%. As a result of the assessment of the resistance of four barley accessions to S. graminum clones, 15 virulence phenotypes were identified. Accessions k-3885, k-3904 and k-4080 each have one dominant resistance allele, which differ from each other and differ from Rsg1.
 CONCLUSIONS: The genetic diversity of barley accessions from Mongolia in terms of greenbug resistance is low. The genotypes of S. graminum differentially interact not only with the major, but also with weakly manifested barley resistance genes.