小麦蓝矮植原体寄主范围的鉴定及RFLP分析

Host range testing and RFLP analysis of wheat blue dwarf phytoplasma

小麦蓝矮是我国首次报道的小麦植原体病害。采用介体接种植物,症状观察和应用植原体16S rDNA基因通用引物对R16mF2/R16mR1进行PCR扩增,在接种小麦和传毒介体中均扩增出1.4kb的特异片段,鉴定出小麦蓝矮植原体新寄主7种。用巢式PCR方法对小麦蓝矮病田自然发病杂草进行分子检测,从表现症状的10种杂草中均扩增出1.2kb的特异片段。利用6种植原体特异性限制性内切酶对10种杂草的扩增片段进行RFLP(restriction fragment length polymor-phism)分析表明:扩增片段的RFLP图谱与目前已知的16Sr I组翠菊黄化植原体的RFLP图谱相近。鉴定出小麦蓝矮植原体田间自然新寄主10种。

Wheat blue dwarf （WBD） is the first phytoplasma disease on wheat. Inoculating test plants through vector, observing symptom and using universal primers （R16mF2/R16mR1） for phytoplasma 16S rDNA were conducted. 1.4 kb DNA fragments were amplified by polymerase chain reaction （PCR） in DNA samples extracted from inoculated wheat and viruliferous Psammotettix striatus L. respectively. And 7 new host plants of WBD were discovered in the lab. 1.2 kb DNA fragments were amplified by Nested-PCR in 10 naturally infected weeds in field. Restriction fragment length polymorphism （RFLP） analysis of Nested-PCR products of 16S rDNA with six special restriction enzymes revealed that most of the digestion pattems by restriction endonucleases coincided with those of Aster yellows （AY） phytoplasma, which belong to the same 16Sr I group phytoplasma. 10 new host plants of WBD were discovered in the field.