Análise discriminante na caracterização de novos descritores em soja [Glycine max (L.) Merrill]

• Ano de defesa: 2007
• Autor(a) principal: Nogueira, Ana Paula Oliveira
• Orientador(a): Sediyama, Tuneo
• Banca de defesa: Carneiro, José Eustáquio de Souza , Araújo, Eduardo Fontes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Soja; Descritor; Glycine max
• Palavras-chave em Inglês: Soybean; Descriptors; Glycine max
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/4816

The objective of this study was to evaluate new morphological characteristics of soybean with the purpose of discriminating cultivars; evaluate the reproductive substages for genotype differentiation; and characterize the growth habit of soybean cultivars. Four experiments were conducted in greenhouse conditions, in the Federal University of Viçosa, carrying out two sowing times in the summer (December and February) and two sowing times in the winter (May and June). The treatments consisted of sixteen soybean cultivars (Pelicano, Viçoja, UFV-1, UFV-16, UFV-18, Conquista, Primavera, FT-Abyara, FT-EStrela, FT-Cristalina, Emgopa-316, DM-339, M-SOY 9001, M-SOY 6101, IAC-Foscarin 31 and Bossier) arranged in a complete randomized design, with five repetitions. Each experimental unit consisted of two plants cultivated in a container containing soil with 1/3 organic matter. The results indicated that it was possible to distinguish the soybean genotypes by the characteristics hypocotyl length, epicotyl length, petiole length of the unifoliate leaf, petiole and rhachis length of the first trifoliate leaf and shape of the unifoliate leaf, however, through the decomposition of the interaction and the estimates of the phenotypic correlations it was found that the hypocotyl and epicotyl lengths are highly influenced by the sowing time, whereas this influence tended to be smaller for the other characteristics. The discriminant analysis showed that these characteristics were not enough to distinguish among all the genotypes, and that better discrimination was obtained in the winter sowing (May). The number of days for the reproductive stages gave the period for each substage (flowering, pod formation, seed formation and maturation), observing that the genotypes with similar vegetative cycle and/or total cycle can be distinguished in their substages, and the stage of pod formation and maturation showed higher determination coefficient. Based on the height, number of nodes between stages R1 and R8 and the proportion of height at the beginning of flowering in relation to the final height, it was found that the studied genotypes showed growth habit of determinate, semi-determinate and indeterminate types. The results allowed the conclusion that the characteristics evaluated during the vegetative phase are useful to distinguish soybean genotypes, as additional characteristics, when an ideal time is established. Differentiating soybean genotypes during seed formation and maturation was more reliable than during the flowering and pod formation. Considering the four sowing times, the studied genotypes Viçosa and UFV-1 showed determinate growth type, UFV-16, UFV-18, M-SOY 9001, DM-339, FT-Abyara, FT-Estrela semi-determinate and IAC-Foscarin-31, Emgopa-316 and Primavera the indeterminate type.