Endogeneity of Beauveria bassiana in soybean plants and its insecticidal activity against larva of Xestia c-nigrum
The endogeneity of Beauveria bassiana Bb-170428 in soybean plants after seed coating, the colonization rate and number in different parts, and the effect of coated plants on the insecticidal activity and growth and development of the larvae of the Xestia c-nigrum were analyed. The results showed that Bb-170428 strains of Beauveria bassiana were successfully colonized in the roots, stems and leaves of soybean plants. The colonization rate was higher in the roots, lower leaves and lower stems, and lower in the upper stems and upper leaves. The colonization number of the lower stems and lower leaves was significantly higher than that of the upper leaves, upper stems and root, the colonization number of lower stems and leaves was significantly greater than that of upper leaves, upper stems and roots. Both the colonization rate and the number reached the peak at 14 d after seeding, and then showed a downward trend. The seed coating treatment of Beauveria bassiana had a significant effect on the growth of soybean plants, and the plants had insecticidal activity against the larva of the Xestia c-nigrum. After feeding for 18 d, the corrected mortality rates of the 1-4 instar larvae reached 53.25％, 37.97％, 27.50％ and 23.75％, respectively. Plants coated with Beauveria bassiana seed were fed with 5th instar larvae, the larval mortality rate and moth malformation rate increased significantly, while the pupation rate, emergence rate and pupa weight decreased significantly, which had adverse effects on the growth and development of elderly larvae. The research results provide theoretical and experimental basis for the development and application of biological-coating agent of Beauveria bassiana, increase a new way of biological control of cutworm, and have important signi-ficance and practical value for green food production and reducing the use of chemical pesticides.
万方数据
维普
