Family number in common bean selection

Abstract

The objective of the present study was to determine the number of families necessary for selection in a segregant population. Nine segregant populations from the bean improvement program of the Federal University of Lavras were evaluated. The number of families varied from 169 to 295, and the average family heritability estimate (h²) for grain production varied from 5.3 to 82.0%. Different sample sizes were simulated using the average family performance. The first sample consisted of 30 families, with each additional sample containing 10 more families, until the total number of families evaluated was reached for each population. One thousand simulations per sample size were performed. These data were used to determine the average, minimum and maximum phenotypic variance and the standard error of the variance. The probability of occurrence of a certain level of phenotypic variance for the corresponding values of 0.0, 0.25, 0.50 and 0.75 of heritability was determined for all families, using a chi² distribution. Based on the results obtained and considering the experimental precision and conditions of the bean improvement programs in this region, the use of less than 100 families would reduce the probability of successful selection.<br>O objetivo desse trabalho foi obter informações que possam auxiliar os melhoristas de feijão, quando da decisão sobre a escolha do número de famílias de uma população segregante que deverá ser avaliada para maior eficiência com a seleção. Para isso, utilizaram-se dados experimentais de avaliação de nove populações segregantes do programa de melhoramento do feijoeiro da Universidade Federal de Lavras, conduzidos no período de 1992 a 1997, com o número de famílias variando de 169 a 295 e com a estimativa de herdabilidade (h²) para a produtividade de grãos, na média das famílias, no intervalo de 5.3 a 82.0%. Utilizando o desempenho médio das famílias, foram simulados diferentes tamanhos de amostras, variando de 10 em 10, a partir de tamanho 30, até o número total de famílias avaliadas em cada caso. Foram efetuadas 1.000 simulações para cada tamanho de amostra. Com os dados foram estimados a variância fenotípica média, a mínima, a máxima e o erro padrão da variância. Utilizando a distribuição de chi² foi estimada a probabilidade de ocorrência de um dado valor da variância fenotípica entre média das famílias, para cada tamanho de amostra, considerando h² nula, ou com valores correspondentes a 0.25, 0.50 ou 0.75 da herdabilidade obtida com todas as famílias sendo avaliadas. Constatou-se que, nas condições da precisão experimental em que são conduzidos os programas de melhoramento do feijoeiro na região, com a utilização de um número de famílias inferiores a 100, a probabilidade de sucesso com a seleção é reduzida

Multigeneration Index in the Within‐Progenies Bulk Method for Breeding of Self‐pollinated Plants

“…The number of progenies assessed varies widely, but normally, in each segregating population, it is <100 progenies (Ferreira et al, 2000). The number of progenies assessed varies widely, but normally, in each segregating population, it is <100 progenies (Ferreira et al, 2000).…”

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Metabolomic analysis for the study of maturation in pediatrics: Effect of confounding factors in a pilot study

“…This sample size was chosen as a compromise between ethical and economical reasons and the power of the analysis, estimated in a 70% following an adaptation of the method by Ferreira et al. using the SSPA package for R . As no differences were detected based on the subjects gender, both male and female piglets will be used.…”

Optimizing the number of progenies and replications in plant breeding experiments

“…Ferreira et al (2000), Pinto et al (2000), based on the stabilization of genetic parameters, considered sample sizes of 100 progenies as satisfactory in breeding of common bean and of 200 progenies for recurrent selection in maize for traits such as yield, with widely acknowledged low heritability. Resende and Duarte (2007) suggested that the quality evaluation of variety trials should be based on the Snedecor F test values, which should not be less than five to qualify the accuracy of an experiment as high.…”