Predição de ganhos genéticos por índices de seleção na população de milho pipoca UNB-2U sob seleção recorrente

Abstract

Com o intento de selecionar progênies superiores para a efetiva concentração de alelos favoráveis em uma população de terceiro ciclo de seleção recorrente intrapopulacional em famílias de meios-irmãos de milho-pipoca, avaliaram-se 192 progênies em delineamento em blocos casualizados com duas repetições em dois ambientes distintos: Colégio Estadual Agrícola Antônio Sarlo, em Campos dos Goytacazes, e Estação Experimental da PESAGRO-RIO, em Itaocara, Rio de Janeiro, em 2004/05. Definiu-se a intensidade de seleção de 15,6%, correspondendo ao número de trinta famílias de meios-irmãos para continuidade do programa. Foram empregados os índices de seleção de Smith e Hazel, Pesek e Baker, Williams, e Mulamba e Mock. O índice de Mulamba e Mock proporcionou as magnitudes mais elevadas de ganhos preditos para a maioria das características, incluindo-se capacidade de expansão e produção, com valores respectivos de 7,16% e 10,00%, na utilização de pesos arbitrários atribuídos por tentativas.

Prediction of genetic gain from selection indices for disease resistance in papaya hybrids

“…However, among the choices of economic weights used to obtain gains by the selective index of Mulamba & Mock (1978), the arbitrary weights tentatively assigned (PT) were those that provided the best distribution of gains for the five traits assessed, with negative predicted selective percentage gain. Thus, similarly to that found by Santos et al (2007), the index of Mulamba & Mock (1978), based on arbitrary weights, led to the best results for the selection Table 2. Estimates of the percentage gains for simultaneous selection based on four criteria of economic weights (1) for five traits (2) evaluated in 67 papaya hybrids derived from crosses between the tester genotypes 'JS 12', 'American', 'Sekati', 'Maradol' and 'SS 72/12' (1) CVg = genetic variation coefficient; DPg = genetic standard deviation, h 2 = heritability, and PT = weights tentatively assigned (10, 10, 100, 100 and 100).…”

Effect of recurrent selection on the variability of the UENF-14 popcorn population

“…This gradual increase was also found in C 4 (Freitas Júnior et al 2009), in which even with the change in the strategy of C 3 with half-sib families by full-sib families in C 4 , gains for grain yield and popping expansion continued increasing. Similar results were observed by Santos et al (2007), who found that with the change of the strategy of inbred families selection, carried out by Daros et al (2002) for selection between half-sib families (Santos et al 2007), gains for popping expansion were satisfactory, as well as the increase in grain yield. Figure 1A represents the regression line of the evolution of UENF-14 popcorn population in relation to grain yield in seven recurrent selection cycles.…”

Simultaneous selection in progenies of yellow passion fruit using selection indices

“…In intrapopulational breeding programs of popcorn aimed at obtaining higher genetic gains for yield and popping expansion, Vilarinho et al, (2002Vilarinho et al, ( , 2003, working with selection of inbred progenies S1 and S2, and Santos et al, (2007), working with the selection of half-sib families, found that the index of Mulamba & Mock provided the best gain estimates. Table 3 shows the results for the selection in two phases using the Elston's index in the first phase and the index of Mulamba & Mock in the second phase.…”