Inheritance of bacterial wilt resistance in tomato plants cropped in naturally infested soils of the state of Tocantins

Abstract

Inheritance of resistance to bacterial wilt caused by Ralstonia solanacearum was studied in tomato plants using the P1, P2, F1, F2 and the two backcross generations obtained from the cross between the Drica and Santa Clara cultivars, which are considered standards for resistance and susceptibility, respectively. The experiment was set up in Palmas, TO, Brazil. The study was carried out in soils naturally infected by the pathogen. The scale of scores proposed by Winstead and Kelman (1952) was used to assess the disease incidence. Scores were attributed to individual plants and after six assessments the area below the disease progress curve (AACPD) was calculated and the bacterial wilt incidence (IMB) in the generations was obtained. Inheritance of resistance to bacterial wilt in tomato plants is quantitative with partial dominance of the alleles that express greater AACPD and IMB, which are oligogenic or polygenic traits.