Genetic variability and agronomic characterization of heat tolerant Lettuce Progenies. / Variabilidade genética e caracterização agronômica de progênies de alface tolerantes ao calor.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The objective of this work was to estimate the genetic variability and the correlations between agronomic characters in thirteen progenies F7 of lettuce, and in the genitors: Verdinha, Regina and Tinto, and in the cultivars Luisa and Baba de Verão. The experiment was conducted in Vitória de Santo Antão PE, in the period from September to December of 2005. The experimental design was random blocks, with three replicates. The following characteristics were evaluated: number of leaves NF, plant fresh weight PFP, plant diameter DP, leaves fresh weight - PFF, stem length CC and bolting PEND. The analysis of variance was highly significant (p <0, 01), by the F test, for all studied characteristics showing that the treatments significantly differed between themselves. In the grouping of the averages by the Scott-Knott test at 5% probability, for all characteristics evaluated, the treatments were united into two distinct groups, with the exception of DP, where the cv. Tinto was situated alone in a third group. The genetic variance was higher for all characteristics evaluated and the heritability higher than 50% shows that there was influence of the environment for all the characters. All the variables showed values ofgenetic and environmental variation coefficients (CVG/CVE) near or higher than unity, except for the character PFF, whose value was 0,78. When bolting was correlated to the other characteristics, the results obtained were significant and positive for most of the combinations, considering the genetic correlations. Under the experimental conditions of this experiment, the progeny 76 had better performance, which, although showing a commercial performance slightly lower than the control, to the genitors and even from other progenies, it stood out in relation to the limiting factors such as stem length and bolting. The genetic variances of all variables were superior to the environmental variances for the evaluated characters.

ASSUNTO(S)

early flowering high temperatures correlações genéticas lactuca sativa l. melhoramento vegetal parâmetros genéticos herdabilidade heritability genetic components alface pendoamento precoce

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