Evaluation of Groundnut Segregating Population for Resistance to Sclerotium rolfsii. using an Efficient Field Screening Technique

Abstract

Background: Stem rot of groundnut caused by Sclerotium rolfsii Sacc. is one of the major constraint to groundnut production in many countries and yield losses upto 10-25% were recorded. Screening of groundnut genotypes for resistance to stem rot under field conditions is complicated by the non-uniform spatial distribution of the pathogen.Methods: A total of 165 segregants derived from TAG 24 and R 9227 were evaluated for resistance to stem and pod rot during rainy and summer seasons by using sick plot technique. The field is artificially inoculated at 30 days interval.Result: Among different parameters, maximum phenotypic variability and heritability were observed for disease at 30, 60, 90 days after sowing. The strong negative associations were observed for disease incidence and plant population and positive association were observed for test weight and pod weight per plant. The higher number of superior segregants was observed for pod weight per plant followed by oil content and test weight as compared to both the parents. Generally, high frequencies of desirable segregants were observed for oil content combined with pod weight per plant followed by test weight and pod weight per plant. Out of 165 lines, only six lines showed moderate resistance to Sclerotium rolfsii with good yield attributing characters, further these lines can be utilized in future breeding programme.