Combining ability of Phaseolus vulgaris L. for resistance to common bacterial blight

Abstract

Many diseases limit dry bean and snap bean yields. Common bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli, is one of the most serious bacterial diseases in dry bean and snap bean that cause crop losses. Since there is no satisfactory chemical control, the use of resistant cultivars is an important control measure. Genetic studies of resistance are important for choosing appropriate breeding methods. Combining ability was determined for disease resistance in three snap bean genotypes (Alessa, Hab 52 and Hab 198) and two dry bean genotypes (Bac-6 and A-794). Plants were inoculated with highly pathogenic isolate CNF 15, using a razor blade procedure in leaves and needle punctures in pods. They were evaluated 7 days after inoculation. Leaves were evaluated on a 1 to 5 scale and pods by lesion diameter. Diallel analysis was conducted using Griffing's model. General combining ability (GCA) was significant for both leaf and pod infection, whereas specific combining ability (SCA) was significant for disease reaction in pods. Bac-6 and A-794 were considered superior genotypes for leaf resistance. Nonadditive effects were predominant in pod reactions, and Alessa x Bac-6, Alessa x A-794 and Hab 52 x Bac-6 were the best combinations.

Capacidade combinatória para características agronômicas em feijão-de-vagem

“…Já o feijão-devagem é consumido quando as vagens ainda estão verdes (BROUGHTON et al, 2003). Como ambos são da mesma espécie e, portanto, de fácil cruzamento, muitas vezes num programa de melhoramento específico para vagem faz-se uso da hibridação entre genótipos de feijão-devagem e feijão comum, principalmente buscando fontes de resistência a doenças neste último, devido à estreita base genética do feijão-de-vagem (RODRIGUES et al, 1998;RODRIGUES et al, 1999).…”

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

“…These authors observed high heritability in a broad and restricted sense, concluding that inheritance of resistance to BGMV in the common bean populations is oligogenic. Rodrigues et al (1999) selected parent lines based on their combining ability for resistance to common bacterial blight. The Griffing II (1956) model was applied for estimating combining ability.…”

“…phaseoli (Smith) and X. fuscans subs. fuscans (Burkholder) Starr and Burkholder] (Rodrigues et al 1999, Valdo et al 2016, anthracnose (Colletotrichum lindemuthianum) (Poletine et al 2006), and tolerance to low temperatures in the plant adult stage (Melo et al 1997).…”

Development of Integrated Disease Control Measures for the Valorisation of Traditional Crops in Southern Italy: The Case Study of Fagioli di Sarconi

“…pods) since the degree of resistance/susceptibility of Phaseolus spp. depends on the plant organ (Aggour et al 1989;Rodrigues et al 1999;Marquez et al 2007). …”