Identification of High-yielding and Late Leaf Spot Disease-tolerant Families in Groundnut (Arachis hypogaea L.)

Abstract

The foliar fungal disease late leaf spot (LLS) caused by Cercospora personata is a major and widely distributed disease. Cause substantial yield loss and in combination with the diseases increased up to 70 per cent in India. Therefore, to reduce the effect of disease and yield penalty effective chemical control mainly depends on multiple fungicide applications which are costly for resource-poor farmers and also raise environmental and health concerns. Therefore, to reduce the cost of production the development of resistant cultivars is an eco-friendly concept, with this research gap study was conducted to identify groundnut families with high yield and resistance to late leaf spot disease. From 60 F7 families of three crosses (GKVK-16 × KCG-2, GKVK-13 × KCG-2 and GKVK-6 × KCG-2 along with checks KCG-6, KCG-2 and TMV-2) which were evaluated in augmented design during Kharif 2017 in disease plot and control plot, disease screening was done using a modified 9-point scale. Disease scoring was done at 60, 90 and 120 days after sowing (pod filling stage). The disease scores were mainly based on the extent of leaf area damage. Results depicted that among the 60 families, 19 families showed consistence performance both at normal and disease plots. However, three families showed differences in the pod yield both at normal and disease plots. The families that exhibited resistance to LLS disease showed per cent yield reduction that ranged from 0-35%, and moderately resistant families exhibited a yield reduction from 35-50%, however, 50-90% yield reduction was observed in the families which showed moderate susceptibility, further more than 100% yield reduction was noticed in the families which are susceptible to LLS disease in three crosses of groundnut. High values of GCV and high PCV, high heritability coupled with high GAM were observed for PDI at 60th, PDI at 90th and PDI at 120th days after sowing in all three crosses. Among 14 superior families six, among 13 superior families eight, and from three superior families one family showed resistance to LLS disease from the cross GKVK-16×KCG-2, GKVK-13×KCG-2 and GKVK-6×KCG-2 respectively. Therefore, these identified families will be forwarded for muti-location disease and further yield stabilization.