Studies On Species Diversity And Molecular Systematics Of Conidiobolus From Anhui Province And Shandong Province

Taxonomy and species diversity of Conidiobolus from Anhui and Shandong were systematically studied. Moreover, nucleotide sequences of the region of 28S nuclear ribosomal DNA were used to infer phylogenic relationships of Conidiobolus.From November 2008 to April 2009, soil samples were collected, and more than 100 isolates were isolated from Tiantangzhai, Langyashan, Guniujiang, Zipengshan, Dashushan of Anhui province and Yangtianshan, Kunyushan of Shandong province. According to the taxonomic system of King and Ben-Ze'ev & Kenneth, the size and shape of spores, secondary conidia and resting spores were used as impotant characters at the species level, and the culture characteristics such as colony morphology and growth rate were regarded as supplementary material.Fourteen Conidiobolus species were identifed, which belong to three subgenera, Delacroixia, Capillidium, and Conidiobolus. Conidiobolus microsporus and Conidiobolus macropapillatus were identified as new species.6 species, Conidiobolus hetersporus, Conidiobolus firmipilleus, Conidiobolus lachnodes, Conidiobolus iuxtagenitus, Conidiobolus brefeldianus and Conidiobolus paulus, are newly recorded in China. There are 5 known species——Conidiobolus thromoides, Conidiobolus osmodes, Conidiobolus coronatus, Conidiobolus incongruous and Conidiobolus polytocus. One unidentified species is probably new for Science. All isolates are deposited in the Anhui Provincial Key Laboratory for Microbial Pest Control, Anhui Agricultural University (RCEF).The genomic DNA from 14 Conidiobolus isolates were extracted from mycelia following the improving CTAB method. With the primer LROR and LR5,28S rDNA region was amplified by the polymerase chain reaction (PCR).1 kb PCR prouducts were purified and sequenced.With 23 sequences of Conidiobolus, including 9 sequences downloaded form GenBank, phylogenetic tree was constructed by MEGA software using neighbor-jioning. Batkoa apiculata was selected as a outgroup.Phylogenetic tree of Conidiobolus included 3 clades with 100% boostrap support in CladeⅠand CladeⅡand with 99% boostrap support in CladesⅢ. These 3 clades were consistent with Ben-Ze'ev& Kenneth's taxonomic system in the three sub-division of the genus. CladeⅠincluded C. firmipilleus, C. microsporus, C. coronatus, C. brefeldianus, C. polytocus, C. incongruous Conidiobolus sp., C. iuxtagenitus and C. macropapillatus,7 species of which produced microspores, and belonged to subgenus Delacroixia in Ben-Ze'ev & Kenneth classification system. CladeⅡcontained C. heterosporus, Conidiobolus pumilus and Conidiobolus bangalorensis. C. lachnodes, C. paulus, C. thromoides, C. osmodes and C. antarcticus were grouped in CladeⅢ, which produced neither elongate conidia nor microconidia, and belonged to subgenus Conidiobolus. Genetic distances of these three groups were distant, reaching the difference of genus. Hence, if the results still complyed with the division based on morphology after sequced more 28S rDNA of Conidiobolus, there were enough reasons to improve the three sub-genera to the genus level.