EVALUATION OF GROUNDNUT (ARACHIS HYPOGEA L.) MUTANT GENOTYPES FOR RESISTANCE AGAINST MAJOR DISEASES OF GROUNDNUT

Abstract

A field experiment was conducted at the Farming for the Future field of the Faculty of Agriculture, Nyankpala campus of the University for Development Studies, UDS, to evaluate groundnut genotypes for resistance against three major groundnut diseases namely early leaf spot (ELS) Cercospora arachidicola, late leaf spot (LLS) Phaeoisariopsis personata and groundnut rosette disease under natural infestation. The experiment was consisted of 6 treatments including four groundnut genotypes (150 Gy, 200 Gy, 250 Gy, and 300 Gy) and two standard checks (Chinese and Nkatie SARI varieties). The treatments were replicated three times in a randomized complete block design. Data were collected on ELS and LLS severity using a modified nine point scale (1-9), while rosette disease score was assessed using a 1-5 disease rating scale. Yield of groundnut and resistance level were also determined at 85 DAP. The results revealed that, mutant genotypes 250 Gy and 200 Gy had the highest yield compared with the other genotypes. The 250 Gy was found to be resistant against all the three major groundnut diseases studied, while the 150 Gy, 200 Gy, 300 Gy and the two controls exhibited moderate resistance. Genotype 200 Gy demonstrated resistance against the rosette disease, while the 150 Gy and 300 Gy showed moderate resistance and the two controls were susceptible to groundnut rosette disease. The ELS and LLS diseases correlated negatively with pods per plant and grain yield, respectively, while the rosette disease showed negative correlation with both pods per plant and grain yield. Genotype 250 Gy was resistant against the three major groundnut diseases, and can be further used in future analytical breeding studies to identify and assess specific genes responsible for the resistance, at molecular level for advanced improvement.