Occurrence of physiological races of phytophthora infestans around local areas of pantnagar

The Phytophthora infestans isolates collected around local areas of Pantnagar during 2005–07 cropping season were analyzed for identification of physiological races by using 20 host differential sets, established the occurrence of seven different high spectrum physiologic races among the 16 isolates of P. infestans tested. These races were, namely, 1.2.4.6.7.11, 1.2.3.4.8.10.11, 1.2.3.7.8.10.11, 1.2.3.4.5.7.8.10, 1.2.3.4.7.8.10.11, 1.2.3.4.6.7.8.9.10 and 1.2.3.4.5.6.7.8.9.10 with six gene, seven gene, eight gene, nine gene and 10 gene complex. All the physiologic races around local areas of Pantnagar belonged to A₁ mating type of P. infestans.