Potencial de caracteres na avaliação da arquitetura de plantas de feijão

Abstract

Resumo -O objetivo deste trabalho foi identificar indicadores efetivos da arquitetura de plantas em feijoeiro, para subsidiar, ou substituir, a avaliação por notas. Trinta e seis linhagens de feijão foram avaliadas quanto aos principais caracteres relacionados à arquitetura de plantas e a caracteres agronômicos, em duas safras. Os experimentos foram realizados em blocos ao acaso, com três repetições, em Coimbra, MG. A análise de trilha indicou que o ângulo de inserção dos ramos, a altura das plantas na colheita e o diâmetro do hipocótilo foram os principais caracteres determinantes da arquitetura de plantas do feijoeiro. O diâmetro do hipocótilo esteve fortemente associado com a nota de arquitetura e possibilitou elevada acurácia e precisão de mensuração. Essa característica é facilmente mensurada e é indicador efetivo da arquitetura de plantas do feijoeiro.Termos para indexação: altura de inserção, colheita mecanizada, diâmetro do hipocótilo, hábito de crescimento, plantas eretas, seleção simultânea. Potential of characters for evaluating common bean plant architectureAbstract -The objective of this work was to identify effective indicators of plant architecture in common bean, to subsidize or replace the evaluation by scores. Thirty-six common bean lines were evaluated regarding the main characters related to plant architecture and agronomic traits, in two harvest seasons. The experiments were carried out in a randomized complete block design with three replicates in Coimbra, MG, Brazil. Path analysis showed that the insertion angle of branches, plant height at harvest, and hypocotyl diameter were the main determinants of plant architecture of common bean. Hypocotyl diameter was strongly related to the architecture score, and allowed high accuracy and precision in measurement. This trait is easily measured and is an effective indicator of bean plant architecture.

Potential of hypocotyl diameter in family selection aiming at plant architecture improvement of common bean

“…Accuracies (heritability at family mean level) for HD and PAG for both seasons were observed; however, HD showed higher precision than PAG, with values below 7% (Table 1). For the evaluation of 36 common bean lines, regarding the traits related to plant architecture, Moura et al (2013) A joint analysis of the seasons (Table 2) showed significant effects (P < 0.01) for both families and controls for the evaluated traits, confirming the high variability between these traits, and is fundamental to the study of genetic control of analyzed characters. Breeders exploit family variability in breeding programs with gains in several traits of common beans.…”

“…However, cultivars of carioca-type bean present some problems, such as a high degree of lodging. Cultivars with the most suitable plant architecture, particularly the erect cultivars, enable mechanized harvesting, a reduction in production loss, and enhanced grain quality (Cunha et al, 2005;Menezes Júnior et al, 2011;Silva et al, 2009Silva et al, , 2013aMoura et al, 2013). Thus, selecting plants with more erect plant architecture has received great attention from bean breeders (Kelly and Adams, 1987;Menezes Júnior et al, 2008).…”

“…However, this evaluation is visual, demands an experienced evaluator, and is difficult to use for individual plants. Thus, in order to identify effective indicators of plant architecture in common bean to support or replace the grade scale and solve these problems, Moura et al (2013), evaluating 36 common bean lines, observed that branches insertion angle, plant height at harvest, and HD were the main traits related to plant architecture.…”

“…Among the traits related to plant architecture, HD stands out due to its strong association of cause and effect with plant architecture grade, and high accuracy and precision in its evaluation. It is noteworthy that, in this study, the correlations were estimated using the lines, and information regarding evaluation between segregating families were not taken into account (Moura et al, 2013). HD is easier to use in evaluations compared to other methods and enables the evaluation of individual plants.…”

Combining ability as a strategy for selecting common bean parents and populations resistant to white mold

“…WM resistance in the field is a trait of complex inheritance, which includes physiological resistance and disease avoidance (Fuller et al 1984, Schwartz et al 1987, Kim and Diers 2000, Kolkman and Kelly 2002, Miklas et al 2013). In general, WM avoidance is associated with morphological and phenological traits, such as upright plant architecture, lodging resistance, canopy porosity and height, and maturity (Miklas et al 2013, Tivoli et al 2013, and these traits are highly influenced by the environment (Teixeira et al 1999, Miklas et al 2013, Moura et al 2013). …”