Ear leucochroism on winter rye cultivars in agroecological conditions of Kirov region

. The purpose of the study is to study the effect of environment and genotype on the expression of ear leucochroism in winter rye plants. Methods. The research was carried out in the laboratory of immunity and plant protection of FASC of the North-East. The conditions and peculiarities of the expression of ear leucochroism and stalk albinosis in 48 domestic varieties of winter rye was studied in field and laboratory experiments. In tested populations, count of such biotypes, phytopathological and microbiological analysis of root system and grain in affected plants were done. Repetition in in vivo studies – 2-fold, in vitro – 4-fold. Results. Five cultivars of a rye bred in FASC of the North-East (Sarmat, Falenskaya universal’naya, Garmoniya, Grafinya, and Perepel) with defeat up to 0.10 %, and 11 domestic cultivars of some Russian research institutions (Moskovskaya 2, Saratovskaya 7, Marusenka, Talovskaya 33, Pamyaty Bambysheva, Solnechnaya, Antares, HBAK-285/15, Slavia, Talovskaya 41, and Alpha) with defeat up to 0.07 % are revealed at a state of this trait at the indicator – 0.31 %. A positive link was found between root infection and plant ear leucochroism (r = 0.15 and r = 0.30), but there was no clear evidence of the dependence of the nature and degree of grain infection on the state of the trait. The level of ear leucochroism is significantly affected by the density of the plant stand due to the resistance to snow mold in regional conditions (r = 0.29 and r = 0.79). The dominant contribution of the genotype to the variability of the sign of ear leucochroism, which amounted to 68.4 % in new populations bred in FASC of the North-East, and in cultivars of domestic breeding – 59.4 %, has been established. A significant effect of the microenvironment (31.0 % and 39.6 %) on pathogenesis, expressed in field test repeats, was also found.