Estimate of Heritability for Maturity Characteristics of an Early x Late Common Bean (Phaseo/us vulgaris /.) Cross (TMO 216 x CIAT 16-1) and Relationships Among Maturity Traits with Yield and Components of Yield

Abstract

Narrow sense heritabilities of maturity characteristics of common beans were estimated using the standard unit method of regression of F₃ on F₂ plants of Early x Late crosses grown in the field plots of the Sokoine University of Agriculture during the growing season of 1991. Correlations and genetic advances (GA) of maturity traits and seed' yield were also determined. Estimated narrow sense heritabilities were high (0.59) for days to first flower (DFF), medium (33.3) for days to physiological maturity (DPM) and low (25.6) for duration of pod fill period (PFP). The high standard errors of PFP indicated high environmental influence on the expression of this trait. The results indicated that additive gene effects play an important. role in the inheritance of DFF, hence early generation selection for this trait would be successful. Selection for duration of PFP should be done at later generations in replicated yield trials.A positive and significant relationship (P 0.05) between seed yield and PFP-2 (r=0.44) suggested that a longer pod fill period might result in a higher seed yield potential. The family means for all maturity characteristics were similar to the mid parent means resulting in small positive values of genetic advance indicating that early maturing lines could easily be selected. Significant negative association between 100 seed weight and maturity indicates that selection for earliness would result in large seeded bean genotypes, which generally have a high preference for mostfarmers and consumers in the tropics.

Keywords: Common beans, heritability, maturity characteristics, Phaseolus vulgaris

Tanzania J. Agric.Sc. (2007) Vol. 8 No.1, 11-18