Study of the race composition of yellow rust in wheat varieties in the conditions of Uzbekistan
Puccinia striiformis F. sp.tritici, causing yellow rust disease, are widespread in grain-bearing countries. This disease has caused great harm to the yield of grain and a decrease in the quality of grain in recent years. The fungus lives and multiplies only in living tissues and in plant cells. Therefore this pathogen infects green cells of cereal plantings and their wild forms at any stage of development before maturity. The pathogen lives and multiplies only in green wheat cells. The article deals with the issues of spread, epidemiology of yellow rust disease and analyses of differentiator variety races. The relationship between yellow rust Puccinia striiformis F. sp. tritici and the air temperature and the degree of reproduction at the initial stages of development of wild cereal plants is studied. The research revealed that yellow rust disease is caused by 237 E 239 races of Puccinia striiformis F. sp. tritici fungus, which includes the genes Yr1, Yr6, Yr2, Yr3V, Yr9 YrSu, Yr4, Yr32, being virulent ones.