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Sixty-five samples were collected from rhizosphere soil,hot pepper and tomato plants showing damping-off,root rot and stem rot in Taian,Shouguang of Shandong province and Zhouzhi,Taibai of Shaanxi province.Thirty-nine Rhizoctonia solani isolates were obtained from these samples.The results of anastomosis group(AG) identification and sequence analysis of 5.8S rDNA-ITS of the isolates showed that thirty-six isolates(92.3%) belonged to AG-4,while only three(7.7%) belonged to AG-5.The isolates of AG-4 could further be divided into two subgroups of AG-4-HG-Ⅰ and AG-4-HG-Ⅲ.The 5.8S rDNA-ITS sequences of the selected isolates of the two subgroups had the 99%-100% identity with standard isolates of AG-4-HG-Ⅰ and AG-4-HG-Ⅲ(from GenBank).Among the analyzed isolates,AG-4-HG-Ⅰ subgroup was the dominant with the frequency of 79.5%.Subgroup AG-4-HG-Ⅲ with the frequency of 12.8% was the second.This is the first report that subgroup AG-4-HG-Ⅲ of R.solani isolated from Solanaceae vegetable crops in China.
Sixty-five samples were collected from rhizosphere soil, hot pepper and tomato plants showing damping-off, root rot and stem rot in Taian, Shouguang of Shandong province and Zhouzhi, Taibai of Shaanxi province. Thirty-nine Rhizoctonia solani isolates were obtained from samples. the results of anastomosis group (AG) identification and sequence analysis of 5.8S rDNA-ITS of the isolates showed that thirty-six isolates (92.3%) belonged to AG-4, while only three (7.7% 5. The isolates of AG-4 could further be divided into two subgroups of AG-4-HG-I and AG-4-HG-III. The 5.8S rDNA-ITS sequences of the selected isolates of the two subgroups had the 99 % -100% identity with standard isolates of AG-4-HG-I and AG-4-HG-III (from GenBank) .Among the analyzed isolates, AG- 4 -HG-I subgroup was the dominant with the frequency of 79.5 %. Subgroup AG-4-HG-III with the frequency of 12.8% was the second. This is the first report that subgroup AG-4-HG-III of R. solani isolated from Solanaceae vegetabl e crops in China.