Genetics of powdery mildew ( Erysiphe polygoni D.C.) resistance in Mungbean ( Vigna radiata (L.) Wilczek)

Abstract

Gene effects were estimated for powdery mildew disease reaction in mungbean to know gene action involved for powdery mildew resistance. Six generations (P 1, P 2, F 1, F 2, B 1 and B 2), of three crosses, PIP 3-85-2×TARM 18, AKM 8802×TARM 18 and PM 9339×TARM 18 were grown for recording disease incidence (DI), per cent disease index (PDI) and area under disease progress curve (AUDPC). Uniformity in the trend was observed for these three parameters. AUDPC values revealed differential rate of disease development on various genotypes of mungbean. Highest rate of disease development was observed on AKM 8802 (973.65) and lowest on TARM 18 (323.82). Both additive and dominance gene actions were found to be important in inheritance of powdery mildew resistance (all the three characters) including non-allelic interactions. Duplicate type of epistasis was detected for disease incidence and complementary for PDI and AUDPC in most of the crosses. The selected plants from early segregating generations may be intermated to accumulate resistance genes and to fix resistance at desired level. Due consideration should be given to quantify disease using AUDPC values.