水稻橙叶病分子检测及其在华南地区的发生与分布研究

对华南地区水稻橙叶病(rice orange leaf disease)进行病原菌分子检测和病情发生与分布调查。结果表明,该病是一种由电光叶蝉(Inazuma dorsalis)和黑尾叶蝉(Nephotettix cinticeps)传播的植原体(Phytoplasma)引起的病害,早期感病植株在分蘖期全株叶片表现为橙黄色,不久干枯死亡,对水稻生产造成严重为害。电镜下观察,病株幼叶叶脉筛管细胞中存在大量植原体。巢式PCR可从来源于水稻病株及介体电光叶蝉和黑尾叶蝉DNA抽提物中获得单一扩增产物,PCR产物核苷酸序列与文献报道的水稻橙叶植原体16S r DNA序列(Gen Bank登录号:KR061356)同一率均为99.8%以上。2015年广东各主要稻区及海南中部和广西东南部均有该病发生与分布。

Molecular detection of rice orange leaf disease and research on its occurrence and distribution in Southern China

Investigation and pathogen molecular detection of rice orange leaf (ROL) disease were conducted in rice growing area of southern China. The results showed that the disease was caused by Phytoplasma transmitted via leafhoppers Inazuma dorsalis and Nephotettix cinticeps. Leaves of early infected rice plants presented orange-yellow at tillering stage and soon became withered and died, which caused serious damage to rice production. A large number of Phytoplasmas were observed in sieve tube cells of infected young leaf under electron microscope. Nest-PCR products were obtained from DNA extractions of infected rice plants and vector leafhoppers I. dorsalis and N. cinticeps with Phytoplasma specific primers, and shared over 99.8% nucleotide identities with reported rice orange leaf phytoplasma16S rDNA sequence (GenBank accession number KR061356). Field surveys showed that the disease was distributed over southern China, including most of Guangdong province, central Hainan and southeastern Guangxi in 2015.