Maruthi M N, Rekha A R, Cork A, Colvin J, Alam S N, Kader K A
Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK.
Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh.
Plant Dis. 2005 Sep;89(9):1011. doi: 10.1094/PD-89-1011C.
Tomato is an important cash crop for resource-poor farmers and accounts for 20% of the 2 million t of vegetables grown annually in Bangladesh. Tomato cultivation is affected by Tomato leaf curl virus (ToLCV), which can cause as much as 100% yield loss. Plants exhibiting typical ToLCV disease symptoms of yellowing, severe leaf curling, and stunting were collected at Jessore, Bangladesh during September 2003. The putative virus was transmitted from tomato to tomato by the whitefly Bemisia tabaci. In two separate experiments, 100% transmission was achieved by using 10 viruliferous B. tabaci adults for each of the 20 test plants that was confirmed by comparing the symptoms on test and virus source plants. Total DNAs were extracted from the symptomatic leaves, and the putative viral genomes were amplified by polymerase chain reaction by using the Deng A and B primers (1). Sequences generated from these primers were used to design virus-specific primers that were used to obtain complete viral sequences. Full-length DNA-A (2,740 nt; GenBank Accession No. AJ875157) and DNA-B (2,688 nt; GenBank Accession No. AJ875158) sequences of a bipartite Tomato leaf curl New Delhi virus from Jessore (ToLCNDV-[Jes]) were obtained, which were most similar to the corresponding sequences of ToLCNDV-(Lucknow) (GenBank Accession No. Y16421) at 95.7% and Tomato leaf curl Gujarat virus-(Varanasi) (Gen-Bank Accession No. AY190291) at 90.6% nt identities, respectively. DNA-A sequences had only 73.2% nt identity with the previously reported monopartite Tomato leaf curl Bangladesh virus (GenBank Accession No. AF188481) (2), confirming the occurrence of mono- and bipartite bego-moviruses in Bangladesh. The virus diversity poses a challenge for ToLCVD management in Bangladesh. References: (1) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (2) S. K. Green et al. Plant Dis. 85:1286, 2001.
番茄是资源匮乏型农民的重要经济作物,在孟加拉国每年种植的200万吨蔬菜中占20%。番茄种植受到番茄卷叶病毒(ToLCV)的影响,这种病毒可导致高达100%的产量损失。2003年9月,在孟加拉国杰索尔收集了表现出典型ToLCV病害症状(发黄、严重卷叶和发育迟缓)的植株。假定的病毒通过烟粉虱从番茄传播到番茄。在两个独立的实验中,通过对20株测试植株各使用10只带毒烟粉虱成虫实现了100%的传播,这通过比较测试植株和病毒源植株上的症状得以证实。从有症状的叶片中提取总DNA,使用邓A和邓B引物通过聚合酶链反应扩增假定的病毒基因组(1)。由这些引物产生的序列用于设计病毒特异性引物,这些引物用于获得完整的病毒序列。获得了来自杰索尔的双分体番茄卷叶新德里病毒(ToLCNDV-[Jes])的全长DNA-A(2740 nt;GenBank登录号AJ875157)和DNA-B(2688 nt;GenBank登录号AJ875158)序列,它们与ToLCNDV-(勒克瑙)(GenBank登录号Y16421)的相应序列相似度最高,核苷酸同一性分别为95.7%,与番茄卷叶古吉拉特病毒-(瓦拉纳西)(GenBank登录号AY190291)的核苷酸同一性为90.6%。DNA-A序列与先前报道的单分体番茄卷叶孟加拉病毒(GenBank登录号AF188481)的核苷酸同一性仅为73.2%(2),证实了孟加拉国存在单分体和双分体双生病毒。病毒多样性给孟加拉国的番茄卷叶病管理带来了挑战。参考文献:(1)D.邓等人,《应用生物学年鉴》125:327,1994年。(2)S.K.格林等人,《植物病害》85:1286,2001年。