Pathogenetic and histopathological changes in wheat inoculated with two populations of Heterodera avenae

Comparative studies were made with two conspecific populations of Heterodera avenue (Delhi and Una (H.P.) populations) on pathological alterations in wheat cultivar HD 2329. Observations were also made on reproduction of both the populations as influenced by the host. The damage threshold, under experimental conditions, was determined to be 5 juveniles (J₂)/g and 10 (J₂)/g of soil for Delhi and Una populations, respectively. Judged on the basis of plant growth parameters, Delhi population appeared to be comparatively more pathogenic than Una population. Although no remarkable differences in histopathological alterations were observed with regard to the both populations, a larger syncytium was invariably associated with feeding site of Delhi population.