ENVIRONMENTAL INFLUENCE ON HERITABILITY AND SELECTION RESPONSE OF MORPHO-PHYSIOLOGICAL TRAITS IN MUNGBEAN

Thirty mungbean (Vigna radiata (L.) Wilczek) genotypes were evaluated at two locations of North West Frontier Province of Pakistan during 2007 and 2008 using randomized complete block design with three replications. Highly significant differences (p <= 0.01) were observed among the genotypes for morpho-physiological traits across years at both locations as well as across years and locations. Location x year effect was highly significant (p <= 0.01) for days to flowering, plant height and nodes plant(-1). Genotype x location interaction was highly significant (p <= 0.01) for days to flowering, maturity, plant height and leaf area, indicating differential performance of mungbean genotypes over the two test locations. Means for flower initiation, physiological maturity, plant height, leaves plant(-1), nodes plant(-1) and leaf area at Peshawar and Swat were 47.2 vs 50.5 days, 86.5 vs 84.2 days, 55.5 vs 52.3 cm, 8.1 vs 8.5, 10.6 vs 10.3 and 181.8 vs 202.4 cm(2), respectively. The genetic variances were greater in magnitude than environmental variances for most of the traits at both locations. Heritability estimates for the morpho-physiological traits were generally greater in magnitude at Peshawar than Swat: 0.63 vs 0.53, 0.75 vs 0.60, 0.81 vs 0.84, 0.73 vs 0.49, 0.56 vs 0.52 and 0.50 vs 0.37 for days to flowering, maturity, plant height, leaves plant(-1), nodes plant(-1), and leaf area, at Peshawar and Swat, respectively. Expected selection response for all traits was greater at Peshawar than Swat suggesting that selection of desirable mungbean genotypes can be effectively carried out at Peshawar.