To identify the pathogen causing a natural epizootic of white muscardine in Tricentrus sp. in a tea plantation and to evaluate its potential for controlling tea green leafhopper Empoasca onukii, cadaver samples collected from the tea plantation were subjected to isolation, purification, and culture. The taxonomic status of the pathogen was determined based on morphological characteristics and phylogenetic analysis using combined sequences of Bloc, RPB1, RPB2, and TEF genes. Population genetic diversity of isolates from different hosts was analyzed using 12 SSR primer pairs. Six strains derived from hosts in Membracidea and Cicadellidae were selected to evaluate their virulence against the 3rd instar nymphs of E. onukii. The results showed that the pathogen causing the natural epizootic of white muscardine in Tricentrus sp. in the tea plantation was B. bassiana. The B. bassiana populations exhibited a high level of genetic diversity, with 100.00% polymorphic loci, a Shannon’s information index of 0.73, and a Nei’s gene diversity index of 0.39. Among the four B. bassiana populations from different hosts, the genetic differentiation coefficient was 0.38 and the gene flow was 0.54, indicating limited genetic exchange among populations. A total of 89 isolates were divided into 31 genotypes and clustered into three groups at a similarity coefficient of 0.68, with group III accounting for 76.40% of the isolates and representing the dominant group. Strain JCPX121 exhibited the highest virulence. After treatment with a conidial suspension at a concentration of 1.0×108 conidia/mL for eight days, the corrected mortality rate of 3rd instar nymphs of E. onukii reached 80.66% and the median lethal time (LT50) was 5.90 d. In summary, strain JCPX121 has the potential to be developed as a biocontrol agent.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |