Potencial de linhagens experimentais de milho (Zea mays L.) para produção de híbridos

Abstract

O sucesso nos programas de melhoramento genético de milho depende da identificação de parentais com boa capacidade de combinação para a produção de híbridos. O objetivo deste trabalho foi identificar linhagens com boa capacidade de combinação utilizando dialelo parcial. Foram avaliadas 16 linhagens, das populações de milho Dentado e Flintisa, em um dialelo parcial onde cada linhagem foi cruzada com as oito linhagens da população contrastante, obtendo-se 64 híbridos simples. Os 64 híbridos foram avaliados em látice triplo em duas safras (semeaduras em 04/07/2009 e 16/11/2009). Ao final de cada repetição do látice foram colocadas as testemunhas comerciais XB 6012, AG 9010, XB 7253 e BG 7049, visando uma comparação simples com os híbridos experimentais. Foram preditos híbridos duplos e triplos. Os caracteres mensurados foram florescimento feminino, altura de plantas, altura de espigas, acamamento e rendimento de grãos. Os híbridos simples 4Dx6F, 7Dx4F, 7Dx6F e 7Dx8F foram indicados para prosseguirem no programa como promissores para as duas safras. Os híbridos simples 1Dx6F, 2Dx8F, 5Dx5F, 7Dx1F, e 7Dx3F foram indicados para prosseguirem no programa como promissores para a primeira safra. Os híbridos simples 3Dx2F, 3Dx3F, 2Dx7F, 5Dx6F, 6Dx3F, 7Dx4F, 2Dx5F, 2Dx6F, 7Dx2F e 7Dx3F foram indicados para prosseguirem no programa como promissores para a segunda safra. Os híbridos triplos mais promissores para a primeira safra de semeadura...

The success in the maize breeding programs depends of the identification of inbred lines with good combining ability for hybrids production. The objective of this study was to identify inbred lines with good combining ability using partial diallel. Were evaluated 16 inbred lines of the maize populations Dentado and Flintisa in a partial diallel where each inbred line was crossed with the eight of the other population, resulting in 64 hybrids. The 64 hybrids were evaluated in a triple lattice in two crop season (sowing on 04/07/2009 and 16/11/2009). At the end of each repetition of the lattice were placed commercial controls XB 6012, AG 9010, XB 7253 and BG 7049, seeking a simple comparison with the experimental hybrids. Were measured the female flowering, plant height, ear height, lodging and grain yield. The hybrids 4Dx6F, 7Dx4F, 7Dx8F and 7Dx8F were appointed to continue in program as promising for the two crop seasons. The hybrids 1Dx6F, 2Dx8F, 5Dx5F, 7Dx1F, e 7Dx3F were appointed to continue in program as promising for the first crop season. The hybrids 3Dx2F, 3Dx3F, 2Dx7F, 5Dx6F, 6Dx3F, 7Dx4F, 2Dx5F, 2Dx6F, 7Dx2F e 7Dx3F were appointed to continue the program as promising for the second crop season. The most promising triple hybrids for the first crop can be obtained as follows: Simple hybrid parental involving inbred lines 1F, 3F, 4F and 8F, with the inbred line 7D; simple hybrid parental involving inbred lines 1D, 2D and 4D, with the inbred line 6F; simple hybrid parental involving inbred lines 3D and 5D, with the inbred line 5F. The triple hybrids more promising for the second crop planting can be obtained as follows: Simple hybrid parental involving inbred lines 3D and 6D, with the inbred line 3F; simple hybrid parental involving inbred lines 4D, 5D and 7D, with the inbred line 6F; simple hybrid parental involving inbred lines 3D and 5D, with the inbred line 2F; simple ... (Complete abstract click electronic access below)