The complete mitochondrial genome of Beauveria lii (Hypocreales: Cordycipitaceae).

The mitochondrial genome of Beauveria lii, strain RCEF500, was sequenced on the NovaSeq 6000 and the Nanopore Sequencer, and annotated. The genome is 59,014 bp in length, encoding 15 conserved protein-coding genes (PCGs), 2 rRNA genes and 23 tRNA genes. The nucleotide composition of Beauveria lii mitochondrial genome was 38.23% of A, 35.81% of T, 11.61% of C, 14.36% of G, 25.97% of G + C content. Phylogenetic analysis confirmed B. lii as a member of Beauveria (Cordycipitaceae). The mitochondrial genome of B. lii will contribute to the understanding of phylogeny and evolution of the genus and family.

Isolation and characterization of two phosphate-solubilizing fungi from rhizosphere soil of moso bamboo and their functional capacities when exposed to different phosphorus sources and pH environments.

Phosphate-solubilizing fungi (PSF) generally enhance available phosphorus (P) released from soil, which contributes to plants' P requirement, especially in P-limiting regions. In this study, two PSF, TalA-JX04 and AspN-JX16, were isolated from the rhizosphere soil of moso bamboo (Phyllostachys edulis) widely distributed in P-deficient areas in China and identified as Talaromyces aurantiacus and Aspergillus neoniger, respectively. The two PSF were cultured in potato dextrose liquid medium with six types of initial pH values ranging from 6.5 to 1.5 to assess acid resistance. Both PSF were incubated in Pikovskaya's liquid media with different pH values containing five recalcitrant P sources, including Ca3(PO4)2, FePO4, CaHPO4, AlPO4, and C6H6Ca6O24P6, to estimate their P-solubilizing capacity. No significant differences were found in the biomass of both fungi grown in media with different initial pH, indicating that these fungi could grow well under acid stress. The P-solubilizing capacity of TalA-JX04 was highest in medium containing CaHPO4, followed by Ca3(PO4)2, FePO4, C6H6Ca6O24P6, and AlPO4 in six types of initial pH treatments, while the recalcitrant P-solubilizing capacity of AspN-JX16 varied with initial pH. Meanwhile, the P-solubilizing capacity of AspN-JX16 was much higher than TalA-JX04. The pH of fermentation broth was negatively correlated with P-solubilizing capacity (p<0.01), suggesting that the fungi promote the dissolution of P sources by secreting organic acids. Our results showed that TalA-JX04 and AspN-JX16 could survive in acidic environments and both fungi had a considerable ability to release soluble P by decomposing recalcitrant P-bearing compounds. The two fungi had potential for application as environment-friendly biofertilizers in subtropical bamboo ecosystem.

[Population genetic structure of Isaria cicadae causing enzootic of cicadas nymphs]. / å¼•è‡´è‰è‹¥è™«åœ°æ–¹ç— çš„è‰æ£’æŸå­¢ç§ç¾¤é—ä¼ ç»“æž„.

The population genetic structure of Isaria cicadae, which caused enzootic of cicadas nymphs in three regions, was analyzed by ISSR marker. The results showed that all three enzootic populations showed high genetic diversity with the highest in the Jingtingshan population and the lowest in the Shitai population. The UPGMA clustering analysis revealed that different enzootic populations did not have a predominant lineage but were polyphyletic and heterogeneous. Genetic lineages had nothing to do with geographical origin. However, two subpopulations of Jingtingshan from different sampling periods were gathered into different clades, which exhibited remarkable temporal heterogeneity. The genetic differentiation (Gst) among populations (subpopulations) was 0.2153 and the gene flow was low at 0.9110 (Nm＜1), which indicated the low gene flow was one of the main reasons for the genetic variation in the population. Therefore, high heterogeneity and low dominance might be genetic structure characteristics of I. cicadae population causing enzootic of cicada nymphs.

[Genetic diversity and population genetic structure of Beauveria bassiana in northern China].

A total of 622 isolates of Beauveria bassiana collected from 13 provinces in northern China were divided into 13 provincial subpopulations, and 568 of the 622 isolates belonging to 8 insect orders and Araneida, whose hosts could be indentified to order level, were divided into 9 host order subpopulations, with the genetic diversity and population genetic structure of the B. bassiana in northern China analyzed by using ISSR (inter-simple sequence repeat) technique. All the diversity indices showed that the B. bassiana in northern China had higher genetic diversity and population heterogeneity. Among the B. bassiana subpopulations, Inner Mongolia subpopulation and Lepidoptera subpopulation showed the highest genetic diversity and population heterogeneity, while Henan subpopulation and Araneida subpopulation showed the lowest ones. The genetic differentiation index and genetic distance between Henan and Liaoning subpopulations and between Araneida and Mantodea subpopulations were the highest, while those between Ningxia and Shaanxi subpopulations and between Coleoptera and Hymenoptera subpopulations were the lowest. The mean genetic differentiation index and mean genetic distance between the host order subpopulations were lower than those between the provincial subpopulations. These results and the subpopulation clustering analysis based on the genetic distance of subpopulations all demonstrated that the genetic lineage of B. bassiana isolates in northern China was associated with neither their geographic origin nor their host origin. The variation of B. bassiana in northern China was mainly caused by the variation between families and between genera of different host orders, and also, caused by the diversity between different collection sites and between different microhabitats within the collection sites.

[Genetic differentiation of Isaria farinosa populations in Anhui Province of East China].

Isaria farinosa is an important entomopathogenic fungus. By using ISSR, this paper studied the genetic heterogeneity of six I. farinosa populations at different localities of Anhui Province, East China. A total of 98.5% polymorphic loci were amplified with ten polymorphic primers, but the polymorphism at population level varied greatly, within the range of 59.6%-93.2%. The genetic differentiation index (G(st)) between the populations based on Nei's genetic heterogenesis analysis was 0.3365, and the gene flow (N(m)) was 0.4931. The genetic differentiation between the populations was lower than that within the populations, suggesting that the genetic variation of I. farinosa mainly come from the interior of the populations. The UPGMA clustering based on the genetic similarities between the isolates revealed that the Xishan population was monophylectic, while the other five populations were polyphylectic, with the Yaoluoping population being the most heterogenic and the Langyashan population being the least heterogenic. No correlations were observed between the geographic distance and the genetic distance of the populations. According to the UPGMA clustering based on the genetic distance between the populations, the six populations were classified into three groups, and this classification was accorded with the clustering based on geographic environment, suggesting the effects of environmental heterogeneity on the population heterogeneity.

[Population genetic structure of Beauveria bassiana from south and southwest Anhui sericultural regions: ISSR analysis].

White muscardine caused by Beauveria bassiana is an important factor affecting sericulture. In the present study, a total of 124 B. bassiana isolates were obtained from the silkworm cadavers, rearing rooms and appliances, surrounding mulberry orchards, pine plantations, and croplands in Jingxian County of south Anhui and Qishan County of southwest Anhui. Together with the mass production strains, the isolates were analyzed for population genetic structure by ISSR markers to trace the origin and the spreading track of the muscardine. The results showed that the two B. bassiana populations in Jingxian County and Qishan County were heterogenic, being monophyletic in Jingxian and polyphyletic in Qishan. Both the Jingxian population and the Qianshan predominant subpopulation were characterized typically by enzootic nature, i.e., low incidence and frequent occurrence, but the Qianshan non-predominant subpopulation could spread among some alternate hosts outside the rearing rooms. The groups prevailing in pine caterpillar populations in the pine plantations of Qianshan and Jingxian, the production strains, and the epizootic strain prevailing in surrounding mantids were all not associated to the silkworm muscardine, displaying safety to sericulture.