云南甘蔗花叶病病原分子鉴定及遗传多样性分析

发布时间：2018-12-11 04:24

【摘要】：蔗糖业是云南区域经济发展和边疆地区脱贫致富的支柱产业。近年来，甘蔗花叶病成为云南各蔗区发生普遍、危害严重的病害，造成甘蔗产量下降、质量降低，严重制约云南蔗糖产业持续稳定发展。2011～2012年，从云南省保山、德宏、红河、临沧、思茅、西双版纳、玉溪、昭通等8个甘蔗主产区和国家甘蔗种质资源圃内采集表现花叶症状的甘蔗样品145份，利用RT-PCR法对其病原进行了检测。在采集到的145份甘蔗样品中，共检测到3种病原：甘蔗花叶病毒（Sugarcanemosaic virus,SCMV），高粱花叶病毒（Sorghum mosaic virus,SrMV）和甘蔗条纹花叶病毒（Sugarcanestreak mosaic virus,SCSMV），其中SrMV检出率达64.13%，为主要病原。SCMV和SCSMV在国家甘蔗种质资源圃的样品中检出率较高，分别达到62.5%和77.78%；大田品种以SrMV为主；在国家甘蔗种质资源圃和保山、红河、玉溪蔗区样品上检测到SCMV；栽培原种部分品种存在SrMV和SCMV复合侵染现象；在国家甘蔗种质资源圃和玉溪、德宏蔗区样品上检测到SCSMV。选取27个SrMV分离物和3个SCMV分离物进行CP基因克隆测序，分析引起云南甘蔗花叶病病原SCMV和SrMV的遗传多样性。序列分析表明：SrMV的CP基因序列差异较大，存在多个株系，且同一地区也存在多个株系，但地理差异不明显，而SCMV不存在株系分化。SrMV CP基因核苷酸序列相似性仅为77%-79%，可能存在一种新的引起甘蔗花叶病的病毒种类。对9个SCSMV阳性样品的CP基因进行了克隆测序，序列分析结果表明：他们之间的同源性较高。从NCBI上下载SCSMV CP基因序列，与本实验获得的9个SCSMV分离物CP基因序列进行聚类分析，结果表明：SCSMV可以划分为多种不同的株系，地理差异比较明显；本研究获得的9个分离物聚集形成一个独立分支，可能代表SCSMV的一个株系。根据样品采集地点，选择RT-PCR检测呈阳性且寄主为红河、保山、德宏、西双版纳、思茅蔗区的主栽品种M2、M3、M6、M9、M17及M32共6个分离物进行鉴别寄主测定，发现它们的致病性存在明显差异，分离物M3有范围最广的鉴别寄主和较强的致病性。
[Abstract]:Sugar industry is the pillar industry of Yunnan regional economic development and frontier area. In recent years, sugarcane mosaic disease has become a common disease in various sugarcane regions in Yunnan Province, causing a decline in sugarcane yield and a decrease in quality, which seriously restricts the sustainable and stable development of sugar cane industry in Yunnan Province. From 2011 to 2012, from Baoshan, Dehong, Yunnan Province, 145 sugarcane samples with mosaic symptoms were collected from 8 main sugarcane producing areas and national sugarcane germplasm nurseries in Honghe, Lincang, Simao, Xishuangbanna, Yuxi and Zhaotong, and their pathogens were detected by RT-PCR method. Three pathogens were detected in 145 sugarcane samples: sugarcane mosaic virus (Sugarcanemosaic virus,SCMV), sorghum mosaic virus (Sorghum mosaic virus,SrMV) and sugarcane stripe mosaic virus (Sugarcanestreak mosaic virus,SCSMV). The detection rate of SrMV was 64.13%. The detection rate of SCMV and SCSMV were 62.5% and 77.78% respectively in the national sugarcane germplasm resource nursery. SrMV was the main cultivar in the field, and compound infection of SrMV and SCMV was found in the samples of sugarcane germplasm resources in Baoshan, Honghe and Yuxi sugarcane regions. SCSMV. was detected in national sugarcane germplasm resource nursery and in Yuxi and Dehong sugarcane area. 27 SrMV isolates and 3 SCMV isolates were selected for CP gene cloning and sequencing. The genetic diversity of SCMV and SrMV causing sugarcane mosaic disease in Yunnan was analyzed. Sequence analysis showed that the sequence of CP gene in SrMV was quite different, there were many lines, and there were many strains in the same area, but the geographical difference was not obvious. However, the nucleotide sequence similarity of. SrMV CP gene in SCMV was only 77-79, which suggested that there might be a new virus causing sugarcane mosaic disease. The CP genes of 9 SCSMV positive samples were cloned and sequenced. The results of sequence analysis showed that there was a high homology among them. The SCSMV CP gene sequence was downloaded from NCBI and clustered with the CP gene sequence of 9 SCSMV isolates obtained in this experiment. The results showed that SCSMV could be divided into many different strains with obvious geographical differences. The 9 isolates collected in this study form an independent branch, which may represent a strain of SCSMV. According to the site of sample collection, six isolates, M2M3M3M6M6M9M17 and M32, were selected from the main cultivars of Honghe, Baoshan, Dehong, Xishuangbanna and Simao sugarcane areas. It was found that there were obvious differences in pathogenicity between them, and the isolate M3 had the widest range of differential hosts and strong pathogenicity.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：S435.661

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