海南槟榔黄化植原体分子检测及其系统发育关系研究

Molecular Detection and Phylogenetic Relationship of Areca Palm Yellow Leaf Phytoplasma in Hainan, China

由植原体引起的槟榔黄化病是海南特色经济作物槟榔种植上的一种毁灭性病害。本研究通过PCR扩增测序、序列多重比对和系统发育分析,对海南部分代表性地区槟榔致死性病原植原体的序列信息与系统发育关系进行检测分析。结果表明:本研究检测的保亭、屯昌、万宁等海南部分代表性地区的槟榔黄化植原体的16SrDNA序列一致;BLAST分析表明各株系16SrDNA与16SrI组植原体同源性为100%。序列多重比对分析表明,本研究各槟榔黄化植原体株系与海南苦棟丛枝、长春花绿变、马松子变叶、辣椒黄化皱缩、蛇婆子丛枝、细圆藤丛枝和日本洋葱黄化、美国翠菊黄化等植原体同源性为100%;与已报道的海南万宁、印度、海南三亚的槟榔黄化植原体16S rDNA序列同源性分别为99.9%、99.9%、99.8%。系统发育分析表明,本研究槟榔黄化植原体与海南苦棟丛枝、长春花绿变、马松子变叶、辣椒黄化皱缩、蛇婆子丛枝、细圆藤丛枝等株系聚于一个分枝,支持率为100%。此外,在发病槟榔叶片、花穗、心叶等组织部位均可检测到植原体。研究结果表明,海南槟榔黄化植原体与海南苦棟丛枝、长春花绿变、马松子变叶、辣椒黄化皱缩、蛇婆子丛枝、细圆藤丛枝等植原体株系的同源性极高,槟榔黄化病很可能会以这些寄主植物作为病原传播载体进行传播扩散。

Areca palm yellow leaf(AYL) disease caused by phytoplasma is a devastating disease in the cultivation of areca palm, an important economic crop in Hainan. Through PCR amplification and sequencing, multiple sequence alignment and phylogenetic analysis, the sequence information and phylogeny of the lethal pathogen infecting areca palm from part representative regions of Hainan were analyzed. The 16 S rDNA sequence of the AYL phytoplasma in part representative areas of Hainan, such as Baoting, Tunchang, Wanning County, were identical. BLAST analysis based on 16 S rDNA showed that the phytoplasm in the study was 100% homology with 16 SrI group phytoplasma. Multiple sequence alignment indicated that the phytoplasma in the study was 100% homology with the phytoplasma strains of Chinaberry witches’-broom, Periwinkle virescence, Melochia corchorifolia phyllody, Pepper yellow crinkle, Waltheria indica virescence, Pericampylus glaucus witches’-broom in Hainan and Onion yellows in Japan, Aster yellow witches’-broom in USA. Homology with the AYL phytoplasma from Wanning, Sanya(Hainan, China) and India was 99.9%,99.9% and 99.8%, respectively. Phylogenetic analysis indicated that AYL strains in the study were clustered into one clade with the phytoplasma strains infecting the plant hosts like chinaberry, periwinkle, Melochia corchorifolia, pepper,Waltheria indica, Pericampylus glaucus in Hainan with 100% bootstrap value. Furthermore, the phytoplasma could be detected in the leaves, flower spikes, and heart leaves from the diseased areca palm. The study indicated that the the homology of the AYL phytoplasmas was significantly high with the strains of chinaberry witches’-broom, periwinkle virescence, Melochia corchorifolia phyllody, pepper yellow crinkle, Waltheria indica virescence, Pericampylus glaucus witches’-broom. AYL disease is very likely to spread using the host plants as pathogen transmission vectors.