Relative heterosis in common bean (<em>Phaseolus vulgaris</em> L.)

Abstract

The characteristic mean number of days to emergence, number of days to flowering, mean height of the first pod insertion, mean longitudinal length of pods, mean final plant height, total number of pods per plant, mean number of seeds per plant, mean number of seeds per pod, mean seed weight and grain yield were assessed to estimate the heterosis of hybrids in relation to the parental means. Six common bean cultivars Phaseolus vulgaris L. and their 15 possible diallel hybrids were assessed in a complete block randomized design with ten replications at the Center of Agricultural Research - CAR, of Universidade Estadual de Maringá, Maringá, State of Paraná, Brazil, in 1997. As for the potentiality for shorter plant emergence and flowering period, the distinguishing combinations were LPSPI 93-17 x FT-Nobre and LPSPI 93-19 x FT-Nobre. As for grain yield, no negative heterotic manifestation occurred, thus indicating that the recombinations obtained may generate superior segregant genotypes. Regarding the grain yield, the highest heterotic values were found in LPSPI 93-19 x Rudá, LIPSPI 93-17 x FT-Nobre, Rudá x Campeão-1, FT-Nobre x Aporé and LIPSPI 93-17 x Aporé combinations with the respective following values: 23.13%, 17.37%, 16.67%, 15.38% and 14.91%, thus leading to the conclusion that precocious and more productive genotypes can be derived from segregant generations.