Evaluation of crop physiological traits in clusterbean (Cyamopsis tetragonoloba L.) and mothbean (Vigna aconitifolia Jacq.)

Abstract

During kharif 2003,41 genotvpes of clusterbean and 47 genotypes of mothbean were evaluated for crop physiological and yield traits The detail growth analysis was performed during vegetative, flowering , seed filling and maturity growth stages. Drought tolerance traits like relative water content (RWC) and specific leaf area (SLA) were measured at these stages. The results indicated genotypic variations for yield, components (biomass, pod yield and seed yield). A significant relationship between SLA and seed yield suggested that low SLA could be an important character for selecting for higher yield. Strong relationship between actual growth rates and derived from thermal time suggested that larger set of germplasm can be evaluated for higher growth rates with ease. Breeders need to record only phenology, biomass & pod weight at maturity to select genotypes with higher crop growth rate and pod growth rate from a larger germplasm instead of tedious sequential growth analvsis. Drought tolerance mechanism in clusterbean and mothbean involves keeping stomata open at lower leaf RWC. Genotypes with above average higher crop growth rate and higher partitioning were selected by bi-plotting of biomass and harvest index for further physiological studies.