Abstract:
In order to investigate the incidence of bacterial wilt in the solanaceae crops such as tomato, eggplant and pepper in South China, the samples were collected from the healthy plants, the plants infected bacterial wilt and their rhizosphere soil. Then, the isolation and identification of pathogenic bacteria, pathogenicity determination and distribution characteristics analysis were carried out. The results showed that: the areas with the highest incidence of bacterial wilt in tomato, eggplant and pepper were Lingshui in Hainan, Jin’an in Fujian and Shaowu in Fujian, respectively. The average incidence rates during their growth period were 20.01%, 5.24% and 23.33%, respectively. A total of 86 strains of
Ralstonia solanacearum were isolated and identified from the solanaceae crops with different geographical origins. The pathogenicity of the isolated
Ralstonia solanacearum was further divided by using the Attenuation index (AI). Among them, 7 strains were non-pathogenic strains (AI larger than 0.75), 13 strains were transitional-type strains (0.65≤AI≤0.75), and 66 strains were high virulent strains (AI smaller than 0.65). The distribution characteristics of
Ralstonia solanacearum were studied. It was found that for different hosts, the distribution characteristics of
Ralstonia solanacearum were that the distribution number of
Ralstonia solanacearum in the diseased plants and their rhizosphere soil was significantly higher than that in the healthy plants and their rhizosphere soil. Moreover, the distribution number in the tissue and soils ranged in the descending order of soil > root > stem. In addition, among the solanaceae crops investigated, the distribution number of
Ralstonia solanacearum in the soil where the plants infected bacterial wilt was greater than 10
6 cfu·g
−1, and the distribution number of
Ralstonia solanacearum in the roots and stems of the plants infected bacterial wilt was greater than 10
5 cfu·g
−1.