选取来自中国、日本和美国的松材线虫(Bursaphelenchus xylophilus)4个虫株,以及中国的拟松材线虫(B.mucronatus)2个虫株进行生物学杂交和交配对象选择试验。结果表明:松材线虫和拟松材线虫的部分虫株可以发生种间杂交,正交总交配成功率为4.2%,反交总交配成功率为10%,反交成功率是正交的2倍。杂交整体发生率极低,杂交后代较难形成可持续的繁殖种群。采用松材线虫(简称Bx)/拟松材线虫(简称Bm)快速分子检测系统对杂交F1代幼虫进行分子鉴定,结果表明F1代幼虫既含有Bx分子标记也含有Bm分子标记。继代培养30 d后,杂交后代在基因型上表现出了不同趋向的分化,其中Bx AN5♀×Bm JNL1♂、Bx AN5♂×Bm AN5♀和BxUSA♂×Bm JNL1♀的杂交后代趋向于成为松材线虫占主导的种群,Bx JNL5♂×Bm JNL1♀的杂交后代趋向于成为拟松材线虫占主导的种群。在有种内交配资源存在情况下,无论松材线虫还是拟松材线虫均倾向于优先选择种内交配资源。研究表明松材线虫和拟松材线虫之间存在一定的生殖隔离,自然状态下种间交配可能会产生,但杂交后代较难形成可持续性繁殖的生殖后代。
In this study,the hybridization was conducted between four Bursaphelenchus xylophilus strains selected from China,Japan,the United States and two B. mucronatus strains selected from China. The results showed that,hybridization could occur between some B. xylophilus strains and B. mucronatus strains,the success rate of negative crossing was two times that of positive crossing,but hybridization rate was extremely low,and the hybrid offspring was difficult to form a sustainable breeding population. The F1 hybrids larvae contained both Bx molecular markers and Bm molecular markers by using Bx / Bm quick molecular detection system. Inter-specific hybrids showed different gene types after subculturing30 days,the offspring nematodes of Bx AN5♀ × Bm JNL1♂,Bx AN5♂× Bm AN5♀ and Bx USA♂× Bm JNL1♀ tended to become the populations which dominant species was Bx,as well as the offspring of Bx JNL5♂× Bm JNL1♀ tended to become the population which dominant species was Bm. If intraspecific matings could happen,both B. mucronatus and B.xylophilus were inclined to have intraspecific mating priority. The adaptability of B. xylophilus in mating was better.There was little possibility of reproductive isolation between Bx and Bm which geographically close,and their inter-specific hybrids were easily to produce. The reproductive isolation existed between B. mucronatus and B. xylophilus,and introgression might happen but hybrids were difficult to form a sustainable reproductive offspring.