ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 80 Number 3
Correlation and path-coefficient analysis of components of seed yield in Bambara groundnut [Vigna subterranea (L.) Verde] germplasm in Botswana. (175)
Twelve landraces of Bambara groundnut IVigna subterranea (L.) Verde] representing the range in the Botswana collection were studied for yield and yield-related characteristics over five consecutive growing seasons during 1994-95 to 1998-99. The rationale was to estimate the degree of phenotypic and genotypic variations of quantitative characteristics whose selection would lead to improvement in seed yield. The landraces showed much diversity for grain yield. Low environmental variability was recorded for the number of seeds per pod, 100-seed weight, and shelling percentage. Genotypic correlation coefficients and path coefficients of number of pods per plant and seed size on seed yield were high. The high heritability of 100-seed weight h2 = 25.14 ± 8.83) indicated that significant increases in yield can be obtained by selection or this trait. Also, lack of negative correlations between pod number and 100-seed weight (rg = 0.177 ± 0.014) was desirable because it would enable selection for both to be done concurrently. The results of this experiment indicated that 100-seed weight and number of pods per plant were the two main parameters that could be used in indirect selection for yield in Bambara groundnut.
Keywords: Autogamy; Bambara groundnut landraces; Botswana collection; Environmental variability; Path coefficient; Selection index; Yield components compensation