Data/hora: 12/06/2024 15:49:22

Provedor de dados: | 124
País: | Brazil
Título: | Heterozygosity level and its relationship with genetic variability mechanisms in beans
Autores: | Melo,Rita Carolina de; Trevisani,Nicole; Pereira,Thayse Cristine Vieira; Guidolin,Altamir Frederico; Coimbra,Jefferson Luís Meirelles.
Data: | 2017-07-01
Ano: | 2017
Palavras-chave: | Phaseolus vulgaris; Multivariate analysis; Orthogonal contrasts; Multiple allelism; Selection intensity.
Resumo: | ABSTRACT Heterozygosity is an extremely important resource in early breeding programs using autogamous plants because it is usually associated with the presence of genetic variability. Induced mutation and artificial hybridization can increase distinctly the proportion of loci in heterozygosis. This study aimed to compare segregating and mutant populations and relate the mechanisms used to generate variability with their respective heterozygosity levels tested. The treatments mutant populations (M2, M3, M4, M5, M6 and M7), segregating populations (F4, F5 and F6) and lines (BRS Pérola and IPR Uirapuru) were evaluated by multivariate analysis and compared by orthogonal contrasts. The canonical discriminant analysis revealed which response variables contributed to differentiate the treatments assessed. All orthogonal contrasts involving the mutant populations showed significant differences, except the contrast between M2 vs. M3, M4, M5, M6, M7. The orthogonal contrast between the mutant and segregating populations denotes a significant variation in the interest in genetic breeding. The traits stem diameter (1.41) and number of legumes per plant (2.72) showed the highest canonical weight in this contrast. Conversely, number of grains per plant (-3.58) approached the mutant and segregating populations. No significant difference was observed in the linear comparison of means F5 vs. F6. The traits are fixed early in the segregant populations, unlike the mutant populations. Comparatively, induced mutation provides more loci in heterozygosis than artificial hybridization. Selection pressure should vary according to the variability creation mechanism used at the beginning of the breeding program.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902017000300480
Editor: | Universidade Federal do Ceará
Relação: | 10.5935/1806-6690.20170056
Formato: | text/html
Fonte: | Revista Ciência Agronômica  v.48 n.3 2017
Fonte: | info:eu-repo/semantics/openAccess