6种柑橘类植物对柑橘衰退病毒分离株TR-L514变异的影响

Influence of six citrus cultivars on the composition of Citrus tristeza virus isolate TR-L514

柑橘衰退病毒(Citrus tristeza virus,CTV)存在复杂的株系分化现象,运用弱毒株交叉保护防治柑橘衰退病时需了解不同类型柑橘对CTV构成的影响。作者将CTV分离株TR-L514嫁接接种到6类柑橘植物上获得了18个亚分离株,并对这18个亚分离株和TR-L514进行了指示植物鉴定,p25基因的限制性片段长度多态性(RFLP)和单链构象多态性(SSCP)分析,p23基因的序列比较。结果表明,CTV株系对不同柑橘类植株的适应性存在差异。TR-L514嫁接到不同柑橘类植株其构成会发生变化,在甜橙上可以同时检测出p25/HinfⅠRFLP第1和6组群,并具有比在其它4类柑橘上更为复杂的SS-CP谱型构成,因此甜橙可能更适宜于CTV的增殖。TR-L514及18个亚分离株的p23基因序列差异可能与不同类柑橘植株的适应性有关。

Citrus tristeza virus （CTV） exists as a large number of distinct strains differing in biological characters in citrus cultivars. Mild strains cross protection （MSCP） as a strategy aimed at controlling severe variants of the pathogen, require deep understanding the influence of citrus cultivars on composition of CTV isolates. 18 subisolates of CTV isolate TR-L514 were obtained by graft from Jin cheng to six citrus cultivars. Biological index was used to detect the pathogenicity on the subisolates and TR-L514. Restriction fragment length polymorphism （RFLP） and single-strand conformation polymorphism （SSCP） assay on p25 gene were conducted, and p23 gene was sequenced. The results indicated that citrus variety might change the composition of CTV isolate, and sweet orange might be more suit to CTV propagation. In sweet orange, TR-L514 was detected to contain p25/Hinf I both group 1 and 6, and showed more complex SSCP patterns than that in other 4 citrus cultivars. The sequence diversity of p23 gene might result in the adaptation to CTV in different citrus hosts.