Multi-locus phylogenetic analyses reveal eight novel species of Distoseptispora from southern China.

IMPORTANCE: Distoseptispora as a single genus in Distoseptisporaceae was introduced by morphological and phylogenetic analyses. Members of this genus occur mainly as asexual morphs, forming effuse, hairy colonies on decaying wood, plant stems, bamboo culms, and fallen leaves and shafts in terrestrial and freshwater habitats. In the present study, saprobic hyphomycetes from plant debris were investigated, and eight new Distoseptispora species were introduced based on morphology and phylogenetic analyses of LSU, ITS, TEF1, and RPB2 sequence data. This study provides important data on the species diversity, ecological environment, and geographical area of Distoseptispora, greatly updates the classification of Distoseptispora, and improves our understanding of the taxonomy of Distoseptispora.

Morphology and Multigene Phylogeny Revealed Three New Species of Helminthosporium (Massarinaceae, Pleosporales) from China.

Saprobic hyphomycetes are highly diverse on plant debris. Over the course of our mycological surveys in southern China, three new Helminthosporium species, H. guanshanense sp. nov., H. jiulianshanense sp. nov. and H. meilingense sp. nov., collected on dead branches of unidentified plants, were introduced by morphological and molecular phylogenetic analyses. Multi-loci (ITS, LSU, SSU, RPB2 and TEF1) phylogenetic analyses were performed using maximum-likelihood and Bayesian inference to infer their taxonomic positions within Massarinaceae. Both molecular analyses and morphological data supported H. guanshanense, H. jiulianshanense and H. meilingense as three independent taxa within Helminthosporium. A list of accepted Helminthosporium species with major morphological features, host information, locality and sequence data was provided. This work expands our understanding of the diversity of Helminthosporium-like taxa in Jiangxi Province, China.

[Chemical composition of body extracts from Apriona germari and its function in sexual communication]. / æ¡‘å¤©ç‰›è™«ä½“æå–ç‰©çš„æˆåˆ†åŠå ¶åœ¨ä¸¤æ€§é€šè®¯ä¸­çš„ä½œç”¨.

To elucidate the composition of semiochemicals of Apriona germari and its function in sexual communication, GC-MS was used to detect the composition of semiochemicals of the overall body and the end abdominal tissue extracts in A. germari. Y-tube olfactometer was used to determine the olfactory response of adult female and male to the standard compounds of the five main extracts. The contact reaction test with male and female adults was performed to the eluted adults that smeared tandard compounds. The results showed that the main ingredients of semiochemicals were alkanes and alkenes with more than 10 carbons. Concentration of (Z)-9-Tricosene was the highest, followed by heptacosane, nonacosane, nonadecene, octacosane, 9-Hexylheptadecane, aldehyde, and ester. Results of the olfactory reaction showed that nonacosane had a significant attractivity to both male and female adults, and that heptacosane had a significant attractivity only to female adults. Nonadecene had a extremely significant repellent activity to female adults. 1-docosene and (Z)-9-Tricosene had no evident role to the male and female adults. Results of the contact test showed that male adults had the strongest courtship responses to the eluted adults with 1-docosene, heptacosane and nonacosane. Female adults had the strongest courtship responses to the eluted adults with nonacosane. Our results indicated that 1-docosene, heptacosane, and nonacosane were important component of the sex pheromone of A. germari, which played an important role in the sexual communication.

Discovery of English grain aphid (Hemiptera: Aphididae) biotypes in China.

The English grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae), is an important pest insect of wheat, Triticum aestivum (L.), in China. Grain aphid biotypes are necessary to breed aphid-resistant wheat varieties; however, none have currently been identified. Here, we describe a method to identify grain aphid biotypes and survey the aphid biotype variation in the wheat growth area of China. Clones of S. avenae were collected from 11 locations in China and used to establish culture populations. These populations were then used to assess the resistance of 12 wheat varieties. Based on resistance responses, seven differential hosts were selected to identify the biotype of S. avenae: Amigo, 'Fengchan No. 3', Zhong 4 wumang, JP1, L1, 885479-2, and 'Xiaobaidongmai'. S. avenae was ultimately classified into five biotypes: EGA I, EGA II, EGA III, EGA IV, and EGA V. These methods provide a mechanism to detect the variation and evolution of grain aphids in different wheat-growing locations and also allow for selection of appropriate aphid-resistant germplasm for wheat breeding of commercial wheat cultivars.

Cellular tropism, population dynamics, host range and taxonomic status of an aphid secondary symbiont, SMLS (Sitobion miscanthi L type symbiont).

SMLS (Sitobion miscanthi L type symbiont) is a newly reported aphid secondary symbiont. Phylogenetic evidence from molecular markers indicates that SMLS belongs to the Rickettsiaceae and has a sibling relationship with Orientia tsutsugamushi. A comparative analysis of coxA nucleotide sequences further supports recognition of SMLS as a new genus in the Rickettsiaceae. In situ hybridization reveals that SMLS is housed in both sheath cells and secondary bacteriocytes and it is also detected in aphid hemolymph. The population dynamics of SMLS differ from those of Buchnera aphidicola and titer levels of SMLS increase in older aphids. A survey of 13 other aphids reveals that SMLS only occurs in wheat-associated species.

A possibly new Rickettsia-like genus symbiont is found in Chinese wheat pest aphid, Sitobion miscanthi (Hemiptera: Aphididae).

In this study, we investigated Rickettsia infection in Chinese wheat pest aphid (Sitobion miscanthi), moreover detected a possibly new Rickettsia-like symbiont, provisionally named as SMLS(1) (S. miscanthi L type symbiont). The sequence of SMLS 16S rRNA gene is 94% similar to that of its presumed closest relative, Orientia tsutsugamushi. If levels of divergence indicate taxonomic distinctiveness, SMLS probably represents a new genus in the family Rickettsiaceae. SMLS occurs in most populations of S. miscanthi, and with divergent infection frequencies, from 5.0% to 93.8%.