ScienceAsia 48 (2022): 247-253 |doi:
Isolation and identification of Cordyceps cateniobliqua Bm1
and its pathogenicity on the silkworm, Bombyx mori
Guanyu Zhua,?, Ping Hea,?, Yu Lia, Mingzhen Maa, Ying Chena, Yong Chena , Fuzhen Suna, Yiling Zhanga,b, Qiang Wanga,b, Zhongyuan Shena,b,?
ABSTRACT: Silkworm?s fungal infection is a kind of communicable diseases caused by parasitic fungi. In this study,
a rare fungal Bm1 strain was isolated from infected silkworms in cocoon production in Zhenjiang city, China. The
result from morphological investigation showed that the conidiogenous cells of the isolated fungal strain had flask-like
phialides with slightly swollen or columnar bases. Most of the conidia were oval and arranged in a broadly ?V?-like
manner that resulted in irregularly curved chains. The color of the fungal colony was white at the initial growing stage
and gradually became pink. The average hyphal growth rate of the strain was 3.42?1.24 mm/d on the PDA solid
medium. Phylogenetic analysis showed that the Bm1 strain was clustered in the same clade with Isaria cateniobliqua,
Cordyceps cateniobliqua, and Evlachovaea kintrischica. Combining the morphological characteristics with rRNA-ITS
sequence, this newly isolated fungal strain was identified as a C. cateniobliqua strain, named as C. cateniobliqua Bm1.
The C. cateniobliqua Bm1 could infect the silkworm through contacting transmission, and the course of this disease was
about 5 to 19 d. The mortality rates of the silkworm caused by infection of C. cateniobliqua Bm1 positively increased
with the concentration of inoculated conidial suspension. The estimated LC50 value was 1.18 ? 109
conidia/ml, a low
pathogenicity to the silkworm compared with the Beauveria bassiana.
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||Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
|| Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu, China
* Corresponding author, E-mail: firstname.lastname@example.org
Received 7 May 2021, Accepted 29 Sep 2021