Inheritance of resistance to Fusarium oxysporum f. sp. phaseoli Brazilian race 2 in common bean

Abstract

Aiming to obtain information concerning the genetic control of the resistance of the bean (Phaseolus vulgaris L.) to the fungus Fusarium oxysporum f. sp. phaseoli, six crosses involving three resistant lines (Carioca MG, Esal 583 and Esal 566) and four susceptible to the fungus (Carioca, CNFC 10443, Uirapuru and Esal 522) were developed. The parental lines, the controls (Carioca MG and Carioca) and the F 1 , F 2 and F 3 generations were evaluated for reaction to Fusarium. For inoculation, root cuttings were immersed in a spore suspension. The evaluations were performed at 21 days after inoculation, by scale of notes ranging from 1.0, to 9.0 and genetic and phenotypic parameters were estimated. The heritability in the narrow sense ranged from 0.34 to 0.42 and in the broad sense of 0.76 to 0.97, showing that selection should be easy, since efficient inoculation and selection methods are used. The average degree of dominance was around 1.0 indicating the presence of dominance in the control of the character, although additive effects are also expressive.

Reação de linhagens de feijoeiro ao fungo Fusarium oxysporum f. sp. phaseoli em condições controladas

“…Há relatos de que o alelo dominante do gene Fop 1, confere resistência à raça 2, também denominada de 'Brasileira', de Fusarium (RIBEIRO; HAGEDORN, 1979). Também utilizando linhagens brasileiras, Pereira et al (2009) evidenciaram que o controle é monogênico. Contudo, a existência de outros genes de efeito menor não deve ser descartada, em razão da ocorrência de ampla variação na expressão fenotípica, conforme verificado por Pereira et al (2008).…”

Resistance to Fusarium wilt in common bean

“…Other authors also observed dominance in the genetic control of Fusarium wilt resistance. Pereira et al (2009) evaluated six crosses involving three resistant and four susceptible lines, and observed complete dominance in Fop resistance genetic control in common bean. The same result was reported by Cross et al (2000) for two F 2 generations of crosses between Fop-resistant and Fop-susceptible Durango common bean parents.…”

“…Fop severity in common bean is usually evaluated only at 21 or 22 days (Pastor-Corrales and Abawi 1987, Cândida et al 2009, Pereira et al 2009). However, in evaluations performed in different years, at different locations and under different managements, as reported by Madden et al (2007), the AUDPC proved effective to differentiate genotypes.…”

“…The integrated disease management of Fusarium Wilt (FW) is limited to crop rotation, seed treatment and use of resistant cultivars. Cross et al (2000) and Pereira et al (2009) stated that the use of resistant cultivars is the most effective method of controlling the economic losses caused by Fusarium wilt.…”

Cultural, Morphological and Pathogenic Variability among Fusarium oxysporum f. sp. phaseoli Causing Wilt in French Bean (Phaseolus vulgaris L.)

“…However, its production is greatly hampered by Fusarium wilt disease. The disease is becoming increasingly important due to its rising levels associated with enhanced spread of the pathogen related to increased mechanization in field activities, repeated planting of similar crop in the same area and production in regular continuous cycles within a single year [10].…”