Seleção recorrente recíproca na obtenção de híbridos interpopulacionais de milho-pipoca

Abstract

Resumo -O objetivo deste trabalho foi avaliar a eficiência da seleção recorrente recíproca em produzir híbridos de milho-pipoca (Zea mays) de progênies endógamas superiores, com famílias de irmãos-completos. O programa de seleção recorrente recíproca envolveu as populações de milho-pipoca 'Viçosa' e 'Beija-Flor'. Os testes dos híbridos S 0 xS 0 e S 1 xS 1 foram conduzidos em delineamento látice, nos anos agrícolas de 2002/2003 e 2004/2005. Os dois ensaios incluíram testemunhas comerciais comuns, que permitiram a comparação do desempenho dos híbridos. Analisaram-se a produtividade e a capacidade de expansão. Foram preditos ganhos direto e indireto com a seleção em capacidade de expansão, avaliada em pipoqueira de ar quente e na pipocadora "Metric Weight Volume Tester". Os ganhos observados foram calculados para avaliar a eficiência da seleção recorrente recíproca. As análises de covariância mostraram variabilidade genotípica nas populações. Em relação às testemunhas comerciais, os híbridos S 0 xS 0 foram inferiores em qualidade e equivalentes em produtividade, e os híbridos S 1 xS 1 foram equivalentes nas duas características. O ganho observado na capacidade de expansão foi substancial, cerca de 4 mL g -1 , superior ao ganho predito (2,8 mL g -1 ). A redução observada na produtividade não foi relevante. Verificou-se redução na variabilidade genotípica quanto à capacidade de expansão. O método de seleção recorrente recíproca foi eficiente em produzir híbridos S 1 xS 1 superiores aos S 0 xS 0 .Termos para indexação: Zea mays, famílias de irmãos-completos interpopulacionais, ganho genético, método dos híbridos crípticos. Reciprocal recurrent selection to obtain interpopulation hybrids of popcornAbstract -The objective of this work was to evaluate the efficiency of reciprocal recurrent selection in producing hybrids of popcorn (Zea mays) from superior endogamous progenies, with full-sibling families. The reciprocal recurrent selection program involved the 'Viçosa' and 'Beija-Flor' popcorn populations. Tests of the hybrids S 0 xS 0 and S 1 xS 1 were carried out in lattice design, in the agricultural years 2002/2003 and 2004/2005. The two assays included common commercial controls, allowing for the comparison of the hybrids performance. Productivity and expansion capacity were evaluated. Direct and indirect gains with selection were predicted on expansion capacity assessed in hot air and Metric Weight Volume Tester popcorn makers. The gains observed were calculated to evaluate the efficiency of the reciprocal recurrent selection. The covariance analyses showed genotypic variability in the populations. When compared to the commercial controls, the S 0 xS 0 hybrids were inferior in quality and equivalent in productivity; and the S 1 xS 1 hybrids were equivalent in both traits. The observed gain in expansion capacity was substantial (around 4 mL g -1 ) and higher than the predicted gain (2.8 mL g -1 ). The reduction observed in productivity was not relevant. Reduction in the genotypic variability was verified for expansi...

Genetic Gains and Selection Advances of the Uenf-14 Popcorn Population

“…Similar h 2 were reported by Faria et al (2008), with values of 50.37% for GY and 60.48% for EC. Therefore, considering the average magnitude of the h 2 , recurrent selection is the most adequate alternative to obtain higher gains, compared to simpler selection methods.…”

“…These results confirm those found by Santos et al (2008) The coefficient of variation of the experiment (CVe) ranged from 9.60 to 21.87%, with the PH, GY and PE characters expressing CVes below 20% (Table 2), which represents a good precision (GOMES, 2000). Faria et al (2008) evaluated the efficiency of reciprocal recurrent selection in popcorn hybrids and found higher CV estimates than those of the present study, for both GY (20.90%) and PC (16%). Although low, the CVes were higher than CVgs, resulting in estimates of Iv below 1.0.…”

Prediction of genetic gains and correlations in corn hybrids for silage

“…Berilli et al (2013) obtained coefficient of experimental variation and heritability of 20% and 56%, respectively, for yield in the 11th reciprocal recurrent selection cycle among corn full-sib families. Faria et al (2008) evaluated the effectiveness of reciprocal recurrent selection in popcorn hybrids, and obtained coefficient of experimental variation (CV e ) and heritability (h 2 ) of 20.90% and 50.37% for yield, respectively. The coefficient of genetic variation (CV g ) expresses the quantity of genetic variation, and allows the breeder to get a sense of the relative magnitude of changes that may be obtained by selection during a breeding program.…”

Recurrent selection of popcorn composites UEM-CO1 AND UEM-CO2 based on selection indices

“…higher for both traits, this direct selection strategy -also called truncated -is inadequate for satisfactory simultaneous genetic gains for two or more traits, as in the case of PE and GY, which are occasionally negatively correlated as well (Pacheco et al 1998, Carpentieri-Pípolo et al 2002, Daros et al 2004b, Faria et al 2008.…”

“…On the other hand, researchers are dedicated to developing superior and adapted genotypes, especially with regard to popping expansion (PE) and grain yield (GY) (Amaral Júnior et al 2013, Ribeiro et al 2016. In some situations, the obstacle of negative correlation between PE and GY has to be overcome, so that the developed product satisfies both producers and consumers (Zinsly and Machado 1987, Carpentieri-Pípolo et al 2002, Broccoli and Burak 2004, Faria et al 2008, Freitas et al 2013.…”