| Botrytis spp., the causal agents of grey mould diseases, can infect many fruits, vegetables and ornamental crops. These fungi are world-wide plant pathogens. It is necessary to keep continuous research on Botrytis taxonomy and identification. The fungal taxonomists all over the world have been making efferts to promote Botrytis taxonomy. Nowadays, there are 28 species in this genus. The genome sequencing of B. cinerea has been completed in 2008. The relationship between Botrytis and host plants has been reported and many new species and diversity of Botrytis have been elucidated.Some researches on morphology, histology, molecular biology and proteomics of Botrytis have made considerable progress. However, it has been short of taxonomic work on Botrytis in China. The morphological and molecular character of Botrytis were identified in this paper. The genetic diversity of Botrytis cinerea isolated from different host in Hubei province was studied based on mophyological characteristics, pathogenicity, resistance and molecular biology techniques. The aim of this study is to determine Botrytis species and diversity of B. cinerea. The results are summarized below:1. The Botrytis cultures were isolated from different hosts and 818 isolates were identied based on morphological and molecular characteristics, including 11 species of Botrytis and 3 Botrytis-like genera. Two new species of Botrytis were described, B. sinoallii causing leaf blight of Allium and B. fabiopsis causing chocolate spot of broad bean. A new disease of garlic caused by B. porri was identified. The taxonomic status of the causal agent of onion bulb rot was determined to be B. aclada, rather than B. allii. Two suspected new species, Botrytis spl. and Botrytis sp2 were identified. Three Botrytis-like species were Amphyobotrys ricini, Streptobotrys caulophylli and Verrucobotrys geranii isolated and identified. In addition, the distribution and the pathogenicity of some species of Botrytis spp. were investigated.2. Phylogenetic relationships were analyzed using the sequence of ITS and G3PDH gene of Botrytis and related genera(Amphyobotrys, Streptobotrys, Verrucobotrys, Sclerotinia, Monilinia). The partial sequence of G3PDH gene can be used for solving the phylogeny problem, compared to ITS. Verrucobotrys is closely related to Botrytis. Verrucobotrys was clustered in an independent branch of a clade of Botrytis in the phylogenetic tree. So, it needs to further investigation that Verrucobotrys was a separate genus needs.3. Two new species, B. fabiopsis and B. sinoallii, were characterized for basic biological properties (the optimum temperature, pH and the optimum carbon and nitrogen sources). The result showed B. fabiopsis could grow in 5-30℃, pH values of 2.0-10.0. The most optimum temperature is 20-25℃for mycelium growth and the most optimum pH value is 4.0-5.0. The most suitable carbon and nitrogen sources were soluble starch and alanine, respectively. B. fabiopsis, B. fabae and B. cinerea showed a dramatic difference in response to temperature, pH value and nutritent sources. B. sinoallii could grow in 5-30℃, pH values of 2.0-10.0 with the optimum temperature of 20℃and ph value of 4.0-5.0. The most suitable carbon and nitrogen sources were glucose and peptone/alanine, respectively. B. sinoallii and B. squamosa also showed a dramatic difference in response to temperature, pH value and nutrient sources. B. sinoallii showed better growth at 25℃and 28℃than B. squamosa.4. The genetic diversity of Botrytis cinerea isolated from different hosts in Hubei Province was studied based on mophyological characteristics, pathogenicity, fungicide resistance and some molecular features. The results showed that:isolates of B. cinerea have three types:mycelium type, conidial type and sclerotial type. A PCR method was developed to identify the transposable elements Boty and Flipper that form two groups, transposa and vacuma. Most of isolates are sensitive to four fungicides. |
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