Carvalho I R, de Pelegrin A J, Szareski V J, Ferrari M, da Rosa T C, Martins T S, Dos Santos N L, Nardino M, de Souza V Q, de Oliveira A C, da Maia L C
Centro de Genômica e Fitomelhoramento, Universidade Federal de Pelotas, Capão do Leão, RS, Brasil
Centro de Genômica e Fitomelhoramento, Universidade Federal de Pelotas, Capão do Leão, RS, Brasil.
Genet Mol Res. 2017 Aug 31;16(3):gmr-16-03-gmr.16039734. doi: 10.4238/gmr16039734.
Genetic improvement is essential to achieve increments in maize (Zea mays L.) grain yield components. It may be obtained through crosses, which enable to exploit the effects of intervarietal heterosis, allelic complementarity, as well as gene actions and effects. This study estimated the components of variance and genetic parameters (REML/BLUP) of an intervarietal diallel to select and predict the best genotypes for maize yield components. The experimental design was randomized blocks containing 60 intervarietal maize hybrids arranged in three repetitions. They were obtained through intervarietal crosses and evaluated in a diallel scheme, where 14 open-pollinated varieties were designated as parentals. Thus, 10 crosses were performed for each hybrid combination to obtain the number of seeds necessary for the competition test. The measured traits were: grain volume relative index, the mass of one hundred grains, and grain yield. The male parents and the additive genetic fraction were determinants for grain volume relative index. Mass of one hundred grains and grain yield were defined by the specific combining ability, and female parents revealed low narrow sense heritability. The female parent Taquarão and male parent Argentino Amarelo presented the best general combining abilities for the measured traits. The specific combining abilities were expressed for crosses AL 25 x Dente de Ouro Roxo, AL 25 x BRS Pampeano, and Taquarão x Argentino Branco. Genetic estimates and predictions were consistent and applicable to breeding programs and could be applied in future quantitative genetic studies of maize.
遗传改良对于提高玉米（Zea mays L.）产量构成要素至关重要。可通过杂交实现遗传改良，杂交能够利用品种间杂种优势、等位基因互补以及基因作用和效应。本研究估算了一个品种间双列杂交的方差成分和遗传参数（REML/BLUP），以选择和预测玉米产量构成要素的最佳基因型。试验设计为随机区组，包含60个品种间玉米杂交种，分三次重复排列。这些杂交种通过品种间杂交获得，并按双列杂交方案进行评估，其中14个开放授粉品种被指定为亲本。因此，每个杂交组合进行10次杂交，以获得竞争试验所需的种子数量。测定的性状为：籽粒体积相对指数、百粒重和籽粒产量。父本和加性遗传部分是籽粒体积相对指数的决定因素。百粒重和籽粒产量由特殊配合力决定，母本表现出较低的狭义遗传力。母本Taquarão和父本Argentino Amarelo在所测性状上表现出最佳的一般配合力。特殊配合力在杂交组合AL 25×Dente de Ouro Roxo、AL 25×BRS Pampeano和Taquarão×Argentino Branco中得以体现。遗传估计和预测结果一致，适用于育种计划，可应用于未来玉米的数量遗传学研究。
