The new downy mildew races of sunflower on Northern Caucasus

OIL CROPS. Scientific bulletin. VNIIMK, 2006, iss. 1 (134). Six Downy Mildew races of sunflower from different regions of Northern Caucasus were identified according to the international nomenclature. There are 700, 710, and 730 of them related to the high virulent. More then 60% of insolates from two agrocenoses belonged to the race 710. Race 330, the most widespread in the all studied regions, was second. The resistance of some hybrids to races 310, 330, 710 was estimated. All of them were resistant to the race 310 and susceptible to race 710, except one. Four races had the differences in DNA spectra with primer PTO.