Genetic parameters of agronomic characters in Panicum maximum hybrids

Revista Brasileira de Zootecnia

Thiago Gomes Dos Santos Braz²  Dilermando Miranda Da Fonseca¹  Liana Jank¹  Marcos Deon Vilela De Resende¹  Janaina Azevedo Martuscello¹  Rosangela Maria Simeão¹ 

[1] ,Universidade Federal de Viçosa Programa de Pós-Graduação em Zootecnia

关键词: Bipolaris maydis;    leaf percentage;    leaf yield;    mixed models;    morpho-agronomic characters;    regrowth;   

DOI  :  10.1590/S1516-35982013000400001

来源: SciELO

【 摘 要 】

This study was carried out with the objective of estimating the genetic parameters of agronomic traits in Panicum maximum hybrids. Genotypes obtained from the crosses between the sexual plants S10 and S12 and cultivars Tanzania and Mombasa were evaluated. The design was an incomplete blocks design with two replicates (clones) and 33 blocks. Each block was constituted by three lines or plots with nine plants each, which were evaluated in six harvests. All the characters presented low broad sense heritabilities for both the individual harvest and for the mean of harvests and a large difference between the heritability and the individual repeatability coefficient, which may be due to the high permanent environmental variance, mainly for forage dry matter and leaf dry matter. On the other hand, the percentage of leaves also presented low repeatability and permanent environmental variance. The genotypic coefficients of variation were high, except for leaf percentage, but they were also associated with high residual coefficients of variation. Both the broad sense heritabilities per harvest and for the mean of harvests were of moderate magnitude for the agronomic traits evaluated in hybrid individuals of P. maximum. On the other hand, there is variability for selection of important characters such as total and leaf dry matter yields and selection for leaf percentage needs a greater number of harvests to improve selection efficiency. The genotypes presented great variability for Bipolaris maydis leaf spot incidence and this character can be included in the P. maximum breeding program.

【 授权许可】

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