江苏桃根腐线虫病病原的形态诊断和致病性测定

 桃根腐线虫病在江苏普遍发生,是国内的一种新病害。在严重发病的徐州眺苗圃病株率和病根率分别高达100%和81%。在幼根上病斑黄褐至褐色,大小不一。未栓化的桃根未见受害。典型病株表现衰退,株矮叶黄,根系发育不良。人工接种来自桃根内外的一种短体线虫,按种桃苗都表现出与自然诱发相似的症状和在病斑内繁殖同样的线虫。按该线虫的主要形态特征和测计数据,鉴定为胡桃短体线虫(Pratylenchus vulnus)。调查和接种的结果表明,草莓也是胡桃短体线虫的一种自然寄主。

PATHOGEN IDENTIFICATION AND PATHOGENICITY OF THE PEACH DISEASE CAUSED BY LESION NEMATODES IN JIANGSU

This study deals with the peach disease caused by lesion nematodes——a new disease in China.The disease was common and serious in Jiangsu prov-ince,especially at a peach nurseary in Xuzhou where all the plants were infe-ctes,with a hight root incident of 81%.The infected yound roots showed varying degree of discoloration and necrosis.Aboveground symptoms were usu-ally in the form retarded growth,eventual stunting and clorosis.The causal nematodes did not infect corkified roots.
Pathogenicity experiments demonstrated that the peach disease in Nanjing was caused by the same species of lesion nematode as that in Xuzhou which was identified as Pratylenchus vulnus.The causal nematode is very similar to P.vulnus,but differs slightly from it in shape of perma the ca(oblong to sub-spherical viz.oblong),tail annules of female 27(20-34)viz.24(22-26) and tail shape variation of female.It was comfirmed that strawberry is also a nutural host of P.vulnus in Nanjing.