Tang J, Elliott D R, Quinn B D, Clover G R G, Alexander B J R
Plant Health and Environment Laboratory, MAF Biosecurity New Zealand, P.O. Box 2095, Auckland 1140, New Zealand.
Plant Dis. 2008 Sep;92(9):1367. doi: 10.1094/PDIS-92-9-1367A.
Hibiscus spp. are popular ornamental plants in New Zealand. The genus is susceptible to Hibiscus chlorotic ringspot virus (HCRSV), a member of the genus Carmovirus, which has been reported in Australia, El Salvador, Singapore, the South Pacific Islands, Taiwan, Thailand, and the United States (1-4). In May of 2004, chlorotic spotting and ringspots were observed on the leaves of two H. rosa-sinensis plants in a home garden in Auckland, New Zealand. When inoculated with sap from symptomatic leaves, Chenopodium quinoa and C. amaranticolor developed faint chlorotic local lesions 12 to 15 days later. Phaseolus vulgaris exhibited small necrotic local spots 10 days postinoculation. No symptoms were observed on inoculated plants of Cucumis sativus, Gomphrena globosa, Nicotiana Clevelandii, N. tabacum, or N. sylvestris. Plants of H. rosa-sinensis and the three symptomatic indicator species tested positive for HCRSV using polyclonal antiserum (Agdia Inc., Elkhart, IN) in a double antibody sandwich (DAS)-ELISA. Forward (5'-GGAACCCGTCCTGTTACTTC-3') and reverse (5'-ATCACATCCACATCCCCTTC-3') primers were designed on the basis of a conserved region in the coat protein gene (nt 2722-3278) of HCRSV isolates in GenBank (Accession Nos. X86448 and DQ392986). A product of the expected size (557 bp) was amplified by reverse transcription (RT)-PCR with total RNA extracted from the four infected species. Comparison of the sequence of the amplicon from H. rosa-sinensis (GenBank Accession No. EU554660) with HCRSV isolates from Singapore and Taiwan (GenBank Accession Nos. X86448 and DQ392986) showed 99 and 94% nucleotide identity, respectively. From 2006 to 2008, samples from a further 25 symptomatic hibiscus plants were collected from different locations in the Auckland region. Nineteen, including plants of H. diversifolius, H. rosa-sinensis, and H. syriacus, tested positive for HCRSV by RT-PCR. To our knowledge, this is the first report of HCRSV in New Zealand and of the virus in H. diversifolius and H. syriacus. HCRSV is considered to be widespread in New Zealand. References: (1) A. A. Brunt et al. Plant Pathol. 49:798, 2000. (2) S. C. Li et al. Plant Pathol. 51:803, 2002. (3) H. Waterworth. No.227 in: Descriptions of Plant Viruses. CMI/AAB, Surrey, UK, 1980. (4) S. M. Wong et al. Acta Hortic. 432:76, 1996.
木槿属植物在新西兰是受欢迎的观赏植物。该属植物易受木槿褪绿环斑病毒（HCRSV）感染，HCRSV是番茄病毒属的成员，已在澳大利亚、萨尔瓦多、新加坡、南太平洋诸岛、台湾、泰国和美国被报道（1 - 4）。2004年5月，在新西兰奥克兰一个家庭花园的两株朱槿叶片上观察到褪绿斑点和环斑。用有症状叶片的汁液接种后，藜麦和千日红在12至15天后出现轻微褪绿局部病斑。接种10天后，菜豆出现小的坏死局部斑点。接种的黄瓜、千日红、克利夫兰烟草、烟草或野生烟草植株未观察到症状。使用多克隆抗血清（Agdia公司，美国印第安纳州埃尔克哈特）通过双抗体夹心（DAS）-ELISA检测，朱槿及三种有症状的指示植物检测出HCRSV呈阳性。根据GenBank中HCRSV分离株（登录号X86448和DQ392986）外壳蛋白基因保守区（核苷酸2722 - 3278）设计正向引物（5'-GGAACCCGTCCTGTTACTTC-3'）和反向引物（5'-ATCACATCCACATCCCCTTC-3'）。用从四种受感染物种提取的总RNA通过逆转录（RT）-PCR扩增出预期大小（557 bp）的产物。将朱槿扩增子序列（GenBank登录号EU554660）与来自新加坡和台湾的HCRSV分离株（GenBank登录号X86448和DQ392986）进行比较，核苷酸同一性分别为99%和94%。2006年至2008年，从奥克兰地区不同地点又采集了25株有症状木槿植物的样本。其中19株，包括阔叶木槿、朱槿和木槿，通过RT-PCR检测HCRSV呈阳性。据我们所知，这是HCRSV在新西兰以及在阔叶木槿和木槿中存在的首次报道。HCRSV被认为在新西兰广泛分布。参考文献：（1）A. A. Brunt等人，《植物病理学》49:798，2000年。（2）S. C. Li等人，《植物病理学》51:803，2002年。（3）H. Waterworth，《植物病毒描述》第227号。英国萨里郡，英联邦真菌研究所/英联邦农业局，1980年。（4）S. M. Wong等人，《园艺学报》432:76，1996年。
