Genetic progress after four cycles of recurrent selection for yield and grain traits in common bean

Abstract

The objective of this study was to evaluate the genetic progress after four cycles of recurrent selection in common bean. The base segregating population was obtained from 10 parents, and derived the S 0:1 and S 0:2 families that were evaluated. The S 0:3 families with higher grain yield and grain color, like the standard carioca were selected, and were intercrossed to generate the population of the following cycle. This process was repeated for four cycles. The best families were evaluated in each cycle by many generations and locations, and the five best lines of each cycle were identified. The 20 lines thus obtained were evaluated in two growing seasons, sown in July and November 2002. The grain yield (kg/ha) and grain type (scale of scores) were evaluated. Genetic progress was confirmed for both traits. The mean annual gain with selection for the grain type was 10.5% and 5.7% for grain yield, with no evidence of variability reduction in the population. These results show that recurrent selection is a good alternative for improving common bean quantitative traits.

Seleção recorrente para três caracteres do feijoeiro

“…A ocorrência de interação para as notas de porte tem sido também relatadas na literatura (COLLICCHIO et al, 1997;TEIXEIRA et al, 1999;CUNHA et al, 2005 As estimativas de herdabilidade para a produtividade de grãos foram muito semelhantes entre os ciclos e, com 95% de probabilidade, são diferentes de zero (Tabela 2). Estimativas de herdabilidade de magnitude semelhante são constatadas na literatura (RAMALHO et al, 2005a;AMARO et al, 2006). No caso da nota de porte, as estimativas de h 2 variaram entre os ciclos, sendo inferior no C 0 , inclusive com chance de assumir valor nulo, limite inferior da estimativa negativo.…”

“…É necessário, entretanto, continuar a seleção com ênfase na identificação de linhagens com porte ereto, alta produtividade e grãos dentro do padrão comercial. Estimativas do PG com a seleção recorrente visando à produtividade de grãos no feijoeiro são relativamente freqüentes na literatura (RANALLI, 1996;BARRON et al, 1999;SINGH et al, 1999;RAMALHO et al, 2005a), porém as metodologias empregadas geralmente são diferentes, o que dificultam as comparações.…”

Genetic progress and potential of common bean families obtained by recurrent selection

“…In the mean of the two seasons, the genetic gain was 8.6%, which is equivalent to 293 kg ha -1 . Genetic gain estimates of recurrent selection in common bean for grain yield from 3.3 to 55% are reported in the literature (Ranalli 1996, Singh et al 1999, Ramalho et al 2005, Menezes Júnior et al 2008, Silva et al 2010. Ramalho et al (2005) evaluated the genetic gain in four recurrent selection cycles in breeding of carioca bean in grain yield and appearance.…”

“…The possibility of introducing new parents during the recombination phases is one of the advantages of recurrent selection (Geraldi 1997, Ramalho et al 2001, making the process much more dynamic. This strategy was successfully applied (Ramalho et al 2005, Menezes Júnior et al 2013). …”

“…Thus, the procedures commonly used to compare selection cycles are assessments of families or lines of the different cycles, which can be done using standard controls (Arantes et al 2010) or the simultaneous assessment of the best families or lines of each cycle (Ramalho et al 2005, Menezes Júnior et al 2013). …”