Avaliação de testadores para capacidade de combinação em linhagens endogâmicas de milho (zea mays l.)

• Autor(a) principal: Pimentel, Alexandre Lopes
• Data de Publicação: 2001
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6762
• topic: Milho; Testadores; Capacidade de combinação; Topcrosses; Maize; Testers; Combining ability; Topcrosses; GENETICA::GENETICA VEGETAL

The main objective of this work is to compare different testes to evaluate for combining ability a group of unselected lines. Twenty eight lines from the CMS 04C population and six testers were used. The testers were the BR105 population, three imbreed lines from the BR105, one single cross proceeding from crossing of two of the used lines as testers and the EMGOPA 501 population. Because of the limited amounts of seeds, the topcrosses of the 20 from the 28 lines were evaluated in two places. The incomplete block design with two common treatments and three replicates were used for the topcrosses evaluation. The trials were installed in 2000/01 season, in the experimental stations of the Planagri company, in Goianésia-Goiás, and at the Escola de Agronomia of Universidade Federal de Goiás, in Goiânia-Goiás.The diallel analysis followed the model of Griffing (1956), adapted by Geraldi & Miranda Filho (1988). The correlations of Spearman, percentage of coincidence based in selection intensity and the variances between topcrosses were used, to compare the testers. It wasn’t observed consistency of the lines rank among the testers and not even for each tester between the two places. The results were different for each place. In Goianésia, the BR105 population, that got greater estimative of General Combining Ability, was the most convenient tester to discriminate the lines. However, in Goiânia, the EMGOPA 501 population, that got the lowest estimative of General Combining Ability, was the most convenient tester to evaluate the lines. In the combined analysis of the two places, the EMGOPA was only able to discriminate the lines. Some lines were superior in hybrid combining and some crossings will have to be evaluated in other environments to confirm its good performance.