Journal of Plant Disease Sciences

Using ten wheat differentials, variation in pathogenic characters was studied among 10 geographically distinct isolates of Tilletia indica viz., KB-1, 2, 5, 6, 8, 13, 14, 15, 30 and 31 collected from the states of Himachal Pradesh, Punjab, Haryana, Rajasthan, Uttar Pradesh and Uttrakhand. KB-1 was most virulent as it induced highly susceptible (HS) reaction in the differentials Wheat HD 2225, WL 6973, PBW 343, and S 486; susceptible (S) reaction in UP 2382 and TL 1210; moderately susceptible (MS) reaction in HD 29 and WL 1562, but it produced moderately resistant (MR) reaction in HD 30 and HD 2288. Three isolates KB-1, KB-15 and KB-31 of Kotputly (Rajasthan), Fatehgarh Sahib (Punjab) and Yamuna Nagar (Haryana) matched aggressiveness with KB-30 of Karnal (Haryana). HD 29 produced MS reaction instead of highly resistant (HR) while UP 2382, TL 1210 and S 486 produced S reaction against KB-1 isolates. Due to nearly identical reaction types, these isolates were placed into one group. Isolates KB-2, KB-5, KB-8 and KB-13 of Pantnagar (Uttarakhand), Ludhiana (Punjab), Radaur (Haryana) and Barnala (Punjab), respectively, resembled aggressiveness to all the host differentials except on HD 29 and HD 30 where KB-8 produced MS and R reaction. Hence these four isolates were clubbed together. Two isolates KB-6 and KB-14 of Ganganagar (Rajasthan) and Bhatinda (Punjab) were least virulent as they produced MS reaction in PBW 343 and failed to infect HD 29, HD 30, UP 2382 and HD 2225. Based on pathogenic variability, ten isolates of T. indica were grouped into three distinct pathotypes, viz., I (highly virulent): KB-1, KB-15, KB-30 and KB-31, II (moderately virulent): KB-2, KB-5, KB-8 and KB-13 and III (least virulent): KB-6 and KB-14.