Reação de genótipos de soja à infecção natural por ferrugem asiática

Abstract

Resumo -O objetivo deste trabalho foi avaliar o progresso da ferrugem asiática (Phakopsora pachyrhizi) em genótipos de soja destinados à produção de silagem, sob condições naturais de infecção. Avaliou-se a severidade da ferrugem ao longo do tempo e a capacidade combinatória de cinco cultivares e 20 progênies F 3 de soja. A maior área abaixo da curva de progresso da ferrugem (AACPF) foi de 2.116, para as progênies originadas do cruzamento entre as cultivares UFVS 2003 x UFV16, e a menor de 1.307, para UFV16 x Tucunaré. Houve efeito significativo das capacidades geral e específica de combinação, para a AACPF entre os genitores e as progênies, bem como para os cruzamentos recíprocos. Esses resultados indicam que a resistência à ferrugem asiática da soja pode ser influenciada por componentes maternos.Termos para indexação: Glycine max, Phakopsora pachyrhizi, cruzamentos recíprocos, dialelo, melhoramento vegetal, resistência. Reaction of soybean cultivars to natural infection by Asian rustAbstract -The objective of this work was to evaluate the progress of Asian soybean rust (Phakopsora pachyrhizi) on Brazilian soybean genotypes destined for silage production, under natural conditions of infection. Rust severity over time and combining ability of five cultivars and 20 F 3 soybean progenies were evaluated. The largest area under rust progress curve (AURPC) was 2,116 for progenies from the cross between cultivars UFVS 2003 x UFV16, and the smallest was 1,307 for UFV16 x Tucunaré. The effects of the general and specific combining abilities for AURPC were significant between the parents and progenies, as well as for the reciprocal crosses. These results indicate that resistance to Asian soybean rust can be influenced by maternal components.

The Impact of Molecular Genetics in Plant Breeding: Realities and Perspectives

“…Significant reciprocal effects on physiological characters such as CO 2 exchange rates, intercellular CO 2 concentration, stomatal conductance, transpiration, plant height, number of branches, fertile nodes, filled pods, seeds per plant, weight of seeds per plant and weight of 100 seeds were detected in soybean by diallel analysis (Karyawati et al, 2015). Using the same analysis Cruz et al (2011) found significant reciprocal effects on resistance to Asian soybean rust (Phakopsora pachyrhizi) and suggested the involvement of cytoplasmic or maternal effects on this trait. Xu et al (2011) looked for QTLs for the seed size traits in soybean using F2:3, F2:4 and F2:5 populations from the direct and reciprocal crosses and employing a multi-QTL joint analysis (MJA) along with composite interval mapping (CIM).…”