福建甘薯病毒病病原鉴定及主要病毒多样性

Identification and genetic diversity analysis of sweet potato virus in Fujian province

摘要:

【背景】病毒病是甘薯的一种重要病害，给甘薯生产带来了严重的经济损失，而生产中甘薯病毒病病原种类复杂多样。【目的】明确福建甘薯病毒病种类、分布及流行，对主要病毒进行多样性分析。【方法】从福建主要甘薯种植区采集病毒病样品，利用PCR/RT-PCR的方法对采集的样品进行病原检测，获得病毒序列，利用Mega 6.0构建系统进化树进行遗传分析。【结果】从福建7个甘薯产区鉴定12种甘薯病毒，包括9种RNA病毒：甘薯羽状斑驳病毒(Sweet potato feathery mottle virus，SPFMV)、甘薯褪绿矮化病毒(Sweet potato chlorotic stunt virus，SPCSV)、甘薯G病毒(Sweet potato virus G，SPVG)、甘薯C病毒(Sweet potato virus C，SPVC)、甘薯2号病毒(Sweet potato virus 2)、甘薯褪绿斑病毒(Sweet potato chlorotic fleck virus，SPCFV)、甘薯潜隐病毒(Sweet potato latent virus，SPLV)、甘薯轻型斑点病毒(Sweet potato mild speaking virus，SPMSV)、黄瓜花叶病毒(Cucumber mosaic virus，CMV)，3种DNA病毒：甘薯卷叶病毒(Sweet potato leaf curl virus，SPLCV)，甘薯无症状1号病毒(Sweet potato symptomless virus 1，SPSMV-1)，甘薯杆状DNA病毒B (SPBV-B)。SPFMV、SPCSV、SPVG和SPLCV检出率最高，分别为50.28%、41.90%、35.75%和24.58%，CMV检出率最低，为2.79%，未检测到甘薯C-6病毒(Sweet potato C-6)和甘薯轻型斑驳病毒(Sweet potato mild mottle virus，SPMMV)。福建甘薯主要以2?6种病毒复合侵染为主，单一侵染率占14.39%，2种以上复合侵染占85.61%。福建SPFMV分离物存在EA、O和RC 3种株系，SPCSV分离物存在WA 1种株系，未发现EA株系，甘薯卷叶病毒分属于2个不同的株系群。【结论】福建甘薯病毒种类多样，以复合侵染为主，且存在多种株系，遗传结构复杂。

Abstract:

[Background] Virus infects sweet potato plants, and causes serious economic losses frequently in Fujian province. There may exist more than one species of sweet potato virus. [Objective] To determine the sweet potato virus species and prevalence in Fujian, and analyze the genetic diversity of the main viruses. [Methods] Viruses were isolated from samples with viral diseases symptoms from different sweet potato production areas in Fujian province, 14 pair primers of viruses infecting sweet potato were used to detect by PCR or RT-PCR. The PCR amplicons of SPFMV (sweet potato feathery mottle virus), SPCSV (sweet potato chlorotic stunt virus) and SPLCV (sweet potato leaf curl virus) from selected samples were cloned and sequenced. The alignments and phylogenetic analyses were performed with the MEGA 6.0 software package. [Results] The results showed that 12 virus species were detected infecting sweet potato in Fujian, of which 9 were RNA viruses, including sweet potato feathery mottle virus (SPFMV), sweet potato chlorotic stunt virus (SPCSV), sweet potato virus G (SPVG), sweet potato virus C (SPVC), sweet potato virus 2 (SPV2), sweet potato chlorotic fleck virus (SPCFV), sweet potato latent virus (SPLV), sweet potato mild speaking virus (SPMSV), cucumber mosaic virus (CMV); and three DNA viruses including sweet potato leaf curl virus (SPLCV), sweet potato symptomless virus 1 (SPSMV-1), sweet potato badnavirus B (SPBV-B). Among 179 sweet potato samples, SPFMV was detected in 90 samples (50.28%), SPCSV was detected in 75 samples (41.90%), SPVG in 64 samples (35.75%), SPVLCV in 44 samples (24.58%), and CMV just in five sample (2.79%), however, no samples infection was detected for SPV-2 and SPMMV. Mixed infections of 2–6 viruses were common (85.61%) in Fujian. The analysis of phylogenetic relationships showed that SPFMV isolates mainly belong to strains of EA, O and RC, SPCSV isolates mainly belong to strains of WA, and SPLCV isolates were divided into two groups. [Conclusion] There were many sweet potato viruses with complex infection models and genetic diversity were proved in Fujian province.