【摘要】 2011年,从广西龙胜梯田的水稻根系和稻田土壤中分离到一种孢囊线虫。该线虫形态特征与已报道的旱稻孢囊线虫(Heterodera elachista)相符,其rDNA-ITS序列与GenBank中旱稻孢囊线虫的rDNA-ITS序列相似性为97.7%~99.3%。rDNA-ITS分子发育树表明该线虫与旱稻孢囊线虫以100%的置信度及较小的遗传距离形成一个单系,据此将该线虫鉴定为旱稻孢囊线虫。进一步对本研究获得的10条旱稻孢囊线虫rDNA-ITS区序列及Tanha Maafi等报道的1条旱稻孢囊线虫rDNA-ITS序列(AF498391)的酶切位点进行分析,结果发现AluⅠ、AvaⅠ、MvaⅠ和RsaⅠ4个内切酶的酶切位点在11条序列中完全一致,而Bsh1236Ⅰ、BsuRⅠ和CfoⅠ3种酶的酶切位点存在变异,其中Bsh1236Ⅰ和BsuRⅠ有2种变异型,CfoⅠ则有3种变异型,表明旱稻孢囊线虫的rDNA-ITS序列存在DNA异质性。更多还原

【Abstract】 In 2011,a cyst nematode was isolated from rice roots and soils in Longsheng Terrace of Guangxi Region, China.Morphological characteristics of the cyst nematode were consistent with previous descriptions of Heterodera ela- chista.The rDNA-ITS sequences of the cyst nematode and H.elachistain GenBank shared 97.7%-99.3%identi- ties.The phylogenetic tree based on rDNA-ITS showed that the cyst nematode was in the same monophyletic clade as H.elachista with 100%support and short branch differences.The results indicated the cyst nematode was Heterodera elachista.The restriction enzyme cutting sites of ten rDNA-ITS sequences of H.elachista amplified and the one reported by Tanha Maafi(GenBank accession number:AF498391)were analyzed.The restriction enzyme cutting sites of AluⅠ,AvaⅠ,MvaⅠand RsaⅠin these 11sequences were identical,however there were 2different patterns after Bsh1236Ⅰand BsuRⅠdigestion,respectively,and 3different patterns after CfoⅠdigestion.The results show intra- species heterogeneity in rDNA-ITS region exists in H.elachista.更多还原