Inheritance of soybean resistance to brown spot (Septoria glycines) in early greenhouse assessments.

• Autor(a) principal: JUNG, R.
• Data de Publicação: 2002
• Outros Autores: TOLEDO, J. F. F. de, ARIAS, C. A. A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/465782
• topic: Melhoramento; Soja

Brown spot disease occurs at the end of the soybean (Glycine max (L.) Merrill) cycle in all cropping regions in Brazil. Under severe conditions, end-of-cycle leaf diseases can reduce crop yield by over 20%. Although the development of resistant cultivars is the most efficient and economical way of disease control, little is known about the genetic mechanism controlling soybean resistance to brown spot. The objective of this study was to investigate the inheritance of resistance to this disease at an early stage (V3/V4) of plant development. The genotypes used were the FT-2 and Davis cultivars, considered resistant and susceptible, respectively, and the F2:3 generation derived from their cross. The experiment was carried out in a greenhouse in a completely randomized design, including 20 plants from each parent and five plants from each 116 F2:3 progenies. The soybean plants were inoculated at the V3/V4 stage and assessed for infection level on the 1st, 2nd and 3 rd leaves at 12, 19 and 26 days after inoculation. The greater susceptibility of Davis compared to FT-2 was confirmed. The F2:3 generation presented reaction to brown spot infection intermediate to the parents. F2:3 based broad sense heritability was predominantly of average magnitude indicating that in spite of the complexity of the trait, with high environmental influence, it is possible to obtain responses to early selection for brown spot resistance under greenhouse conditions when progenies are assessed.