Effect of Beauveria bassiana on the Virulence and Fecundity of Myzus persicae Feeding on Different Tabacco Varieties

PurposeTo verify the pathogenicity of Beauveria bassiana against the Myzus persicae (Sulzer) feeding on the tobacco variety of Honghuadajinyuan (Hongda) and K326 and provide support for the higher virulent fungi isolates screening.

MethodThe pathogenicity of B. bassiana Bb0816 on M. persicae was collected from Hongda and K326 by using the immersion method, the time-dosage effect was evaluated using the Time-Dosage-Mortality Model.

ResultB. bassiana Bb0816 showed a higher virulence against the M. persicae feeding on the tobacco variety of Hongda and K326, it was inconsistent with the Time-Dosage-Mortality Model, the infection efficacy indexes were 0.527 and 0.532 for M. persicae feeding on Hongda and K326, respectively. The mortality increased with the increase of the time after the inoculation, but it increased quickly on the M. persicae feeding on Hongda than that on K326, the maximum mortality was on the 4^th to 5^th day for M. persicae feeding on Hongda, but on the 5^th to 6^th day for M. persicae feeding on K326. From the result of the infection dosage, the LC₅₀ and LC₉₀ for M. persicae feeding on Hongda were lower than feeding on K326. From the result of the infection time, the LT₅₀ and LT₉₀ for M. persicae feeding on Hongda was lower than feeding on K326 under the same conidia concentration. From the fecundity factors of M. persicae, the r_m, R₀ for M. persicae feeding on Hongda was lower than feeding on K326 under the conidia concentration of 1.35×10⁵ conidia/mL to 1.35×10⁸ conidia/mL, and they were all lower than that in CK. No significance difference was found for the generation stage of M. persica feeding on Hongda and K326 under the conidia concentration of 1.35×10³, 1.35×10⁴ and 1.35×10⁵ conidia/mL, but it was lower on M. persica feeding on Hongda than on K326 under the concentration of 1.35×10⁷ and 1.35×10⁸ conidia/mL.

ConclusionThe variety of tobacco affects the pathogenicity of B. bassiana against the M. persica, the virulence was higher on the M. persica feeding on Hongda and K326 under the higher conidia concentration.