Análise dialélica parcial em gerações avançadas para seleção de populações segregantes de trigo

Abstract

Resumo -O objetivo deste trabalho foi estimar, em gerações avançadas, os efeitos da capacidade geral e específica de combinação de genitores de trigo, bem como selecionar populações segregantes superiores. Doze genitores e suas 36 populações nas gerações F 2 e F 3 , obtidas em arranjo de dialelo parcial, foram avaliados quanto à produtividade de grãos. Utilizou-se o delineamento em látice 7x7, com duas repetições, mais um tratamento para completar o látice. O efeito de capacidade geral de combinação foi significativo, nas duas gerações. Observou-se alta correlação (0,83) dos efeitos de capacidade geral de combinação entre gerações, mas inexpressiva influência dos efeitos de gerações e de anos na classificação dos cruzamentos. As populações provenientes do cruzamento entre os genitores BRS 254, BRS 264 e IAC 364 (Tucuruí III) e os genitores MGS 1 Aliança, VI 98053 e UFVT 1 Pioneiro apresentam maior potencial para obtenção de linhagens superiores, quanto à produtividade de grãos. O uso da análise dialélica parcial em gerações avançadas é promissor para programas de melhoramento de trigo por hibridação.Termos para indexação: Triticum aestivum, capacidade de combinação, melhoramento de plantas, predição do potencial genético. Partial diallel analysis in advanced generations for selection of wheat segregating populationsAbstract -The objective of this work was to estimate the effects of general and specific combining ability of wheat parental lines in advanced generations, and to select superior segregating populations. Twelve parental lines and their 36 populations in F 2 and F 3 generations, obtained in a partial diallel arrangement, were evaluated for grain yield. The experimental design used was a 7x7 simple lattice with two replicates, plus a treatment to complete the lattice. The effect of general combining ability was significant in both generations. There was high correlation (0.83) of the effects of general combining ability between generations, but inexpressive influence of the effects of generations and years were observed on the classification of crossings. The populations derived from the crossings between the parental lines BRS 254, BRS 264, and IAC 364 (Tucuruí III) and the parental lines MGS 1 Aliança, VI 98053, and UFVT 1 Pioneiro show the greatest potential for obtaining superior lines for grain yield. The use of the partial diallel analysis in advanced generations is promising for wheat breeding programs through hybridization.

Combining ability in elephant grass (Pennisetum purpureum Schum.) for energy biomass production

“…In the contrast between groups for the morphoagronomic traits in the mean between the two evaluation cuts in the wet season, only the mean squares of the traits HGT and LW were significant at the level of 1% probability by the F test (Table 1). This fact evidences that, for the traits SD, NT, %DM, and DMY, the average number of favorable alleles is similar in both groups of parents as a result of the presence of productive genotypes in both groups (Pimentel et al, 2013).…”

“…Thus, the presence of dominance deviations indicates that the exploration of the hybrid is favorable (Cruz et al, 2012). Therefore, these analyses are important in the choice of the method for directing populations in a breeding program (Pimentel et al, 2013). Among the most commonly used crossing arrangements is the Griffing (1956) method, which provides the estimate of the specific and general combining abilities (SCA and GCA, respectively) and a reduction in the number of crosses.…”

Choosing parent tropical wheat genotypes through genetic dissimilarity based on REML/BLUP

“…from those fixed for the same trait in the other group, generating complementarity between gene loci and, consequently, resulting in the generation of superior transgressive segregates. Some studies have been conducted involving partial diallel analysis of wheat in which the establishment of the groups did not obey criteria based on genetic diversity, which lead to low genetic complementarity, both general and specific (Pimentel et al 2013a, Pimentel et al 2013b).…”

Combining ability as a strategy for selecting common bean parents and populations resistant to white mold

“…For this reason, to better understand genetic control of the target trait and to establish more efficient selection strategies, it is important to study the performance of populations in more advanced generations, such as the F 6 populations evaluated in the present study (Melo et al 1997, Pimentel et al 2013). However, the higher mean square of GCA II in relation to SCA indicates greater importance of the additive effects, and the R 2 values confirm these results.…”