Genetic Variations and Contributions of Some Floral Traits to Pod Yield in Bambara Groundnut (Vigna subterranea L. Verde) under Two Cropping Seasons in the Derived Savanna of the South-East Nigeria

摘要

This study was conducted to determine the genetic variation, character association and path coefficient analysis between floral traits and pod yield of 13 bambara groundnut {Vigna subterranea L. Verde) genotypes. The genotypes were evaluated in replicated field experiments at the Deptartment of Crop Science Research Field, University of Nigeria, Nsukka in the early and late planting seasons. The result showed significant differences among the genotypes in most of the traits studied. The genotypic andheritabilty estimates were high in pistil length, stamen length and stigma-anther separation at both planting dates indicating that these traits have high transmitting ability to next generation and therefore, selection of these traits would be more efficient. The number of pods per plant had significant positive correlation with anther diameter in the early planting . However, number of pods per plant recorded negative correlation values with stigma-anther separation in the early and late planting indicating that decrease in stigma-anther separation will favour pod set in bambara groundnut. The path coefficient analysis showed that anther diameter had the highest positive direct effect (0.57) on number of pods per plant, followed by pistil length (0.25) in the early planting. In the late planting, stamen length had the largest positive direct effect (1.19) on number of pods but was masked by the negative indirect effect via pistil length (-1.27) and stigma-anther separation (-0.44) resulting in thesignificant negative correlation of the number of pods per plant with stamen length. Therefore, genotypes with large anthers could be reliably looked for, while selecting high yielding genotypes in the early planting. However, selection of genotypes withreduced stigma-anther separation and shorter pistil should be adopted in the improvement of the crop during late planting.