Breeding black seeded dry bean lines resistant to anthracnose and desirable agronomical characteristics

Abstract

Several crosses among black seeded common bean (Phaseolus vulgaris L.) lines resistant to anthracnose and exhibiting desired adaptation and plant type were performed. Segregating populations F₂ to F₄ inoculated in the field with race alpha-Brazil of Colletotrichum lindemuthianum Sacc. & Magn. at a concentration of 1.2 x 106 conidia/ml, were submitted to negative mass selection. Plants rating more than grade 4 were eliminated. In F₄, and at harvest time, individual selection was performed to generate F₅ lines. These lines were inoculated and evaluated for resistance to anthracnose as previously described. F₆ and F₇ lines were submitted to yield evaluations using the cultivar Diamante Negro as a control. The 143 selected lines with superior yield performance were tested using four races of the fungus. The results showed that 124 (86.7%), 117 (81.8%), 120 (83.9%), 129 (90.2%) and 88 (61.5%) lines were resistant to alpha-Brazil, delta, zeta, kappa and all four races, respectively. In addition to the resistance to these four races, when plant type and adaptation rating less than or equal to grade 4 were taken into consideration, only 30 lines with yields ranging between 2.278 and 4.095 kg/ha were selected.