[Screening for virulence strains of Metarhizium against Dorysthenes hydropicus pascoes].
OBJECTIVE
The aim of the present study was to screen the Metarhizium strains with high virulence against the larvae of Dorysthenes hydropicus, a serious pest of Citrus grandis.


METHODS
Thirty six strains of Metarhiziums were isolated from the soil of C. grandis GAP base and collected from other institutions, and the pathogenicity of these strains against 1st instar larvae of D. hydropicus was detected at concentration of 1 x 10(8) conidia/g. The high violence strains against D. hydropicus were cultivated in sabouraud dextrose yeast medium at first, then transfer to rice grain. And the sporulations of these violent strains against D. hydropicus were detected.


RESULTS
Twenty-eight strains showed virulence against D. hydropicus by preliminary study, and 7 strains of them were collected for further study, 6 of the 7 showed high virulence, the highest cadaver rate was higher than 74%. The conidia production of strain 1 and strain 4 were 2.35 +/- 0. 25 (1 x 10(9) conidia/g), 2.21 +/- 0.27 (1 x 10(9) conidia/g), respectively, showed significantly higher than other strains.


CONCLUSIONS
Strain 1 and strain 4 of the 36 Metarhiziums strains showed high virulence against D. hydropicus, and the highest sporulation ability, so they have a best application prospect.
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Wei-Si
WS
Ma
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Hai-Li
HL
Qiao
Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Xiang-Qun
XQ
Nong
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Jun
J
Chen
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Jin
J
Yu
Huazhou Green Co., Ltd., Huazhou 525100, China.
Rong-Min
RM
Qin
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Chang-Qing
CQ
Xu
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Jiang
J
Xu
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Sai
S
Liu
Huazhou Green Co., Ltd., Huazhou 525100, China.
Xiang-Ming
XM
Li
The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Hui-Zhen
HZ
Cheng
D000818:Animals; D002957:Citrus / Q000469:parasitology*; D001517:Coleoptera / Q000382:microbiology*; D052981:Metarhizium / Q000254:growth & development / Q000302:isolation & purification* / Q000472:pathogenicity*; D010572:Pest Control, Biological; D010935:Plant Diseases / Q000469:parasitology* / Q000517:prevention & control; D012988:Soil Microbiology; D013172:Spores, Fungal / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity; D014774:Virulence