Elucidation of Phenotypic Characters in Brassinosteroid Treated Compatible and Incompatible Tomato Plants during Nematode Stress

In the present study, in vitro analysis of HBl treated tomato cultivars: compatible (Pusa Ruby) and incompatible (PNR7), was conducted during the pathogenesis of root-knot nematode. Sterilized seeds of selected cultivars were treated with different concentrations of HBl and grown under controlled conditions. Seedlings were further inoculated with infective juveniles of M. incognita. Phenotypic characters (percentage germination, total plant height, total plant biomass and number of galls) were assessed at different time intervals (24, 72, 120, 168 h) post-nematode inoculation in both the cultivars. Analysis of results showed a positive impact of HBl on plant growth while a deleterious effect was seen on nematode development. Furthermore, when the two cultivars were compared for plant growth parameters, overall higher values were determined in PNR-7 as compared to Pusa Ruby. Likewise, when these cultivars were compared at different time intervals for plant growth parameters, more prominent results were found 72 h post-nematode inoculation. Hence, the study revealed defensive role of 28-Homobrassinolide on the phenotypic characters of tomato cultivars under nematode stress.