Linhagens de feijoeiro comum com fenótipos agronômicos favoráveis e resistência ao crestamento bacteriano comum e antracnose

Abstract

Common bacterial blight and anthracnose diseases, incited by Xanthomonas axonopodis pv. phaseoli (Smith) Vauterin, Hoste, Kesters & Swings and Colletotrichum lindemuthianum (Sacc. & Magn.) Scrib., respectively, are major constrains for dry bean (Phaseolus vulgaris L.) production. The main objective of this work was to obtain lines resistant to common bacterial blight, anthracnose and desirable agronomic characteristics. Thirty five F2 populations from single crosses between lines having resistance to common bacterial blight originated from P. acutifolius A. Gray, with bush plant type lines having lodging and anthracnose resistance, were obtained. Segregating populations from F2 to F5 inoculated in the field with spore suspension of pathotype 89 of C. lindemuthianum at a concentration of 1.2 x 106 conidia/ml, were submitted to negative mass selection. Plants showing score higher than 4 were eliminated. In F5, at harvest time, individual selection was performed to alelorate F6 families. The F6 families were evaluated by inoculation with pathotypes 55, 89, 95 and 453 of C. lindemuthianum. The F7 anthracnose resistant families were inoculated in the greenhouse by clipping the primary leaves with scissors dipped in a bacterial suspension of 5 x 107 cfu/ml of XpCNF 15 isolate of X. axonopodis pv. phaseoli. Resistant lines were evaluated in four yield trials. Seventeen high yielding non lodging lines, resistant to common bacterial blight and anthracnose with upright plant type were selected.