【摘要】 以甘薯抗茎线虫病品种徐781和感茎线虫病品种徐薯18的杂交F1分离群体的174株单株为材料,对甘薯抗茎线虫病基因的遗传进行了分析。结果表明,徐781的抗茎线虫病为单基因控制,推测其基因型为Rrrrrr,徐薯18的基因型为rrrrrr。采用BSA-RAPD相结合的方法,筛选940条随机引物,发现10条引物在抗、感池间表现多态性。用这10条引物检测两亲本及建池单株,发现只有引物OPP03在8株抗池单株中扩增出一条在8株感池单株中所没有的特异条带,认为该标记与甘薯抗茎线虫病基因连锁。根据该标记对F1代174个单株的扩增结果,利用Mapmaker3.0软件计算遗传距离,表明该标记与抗茎线虫病基因间的遗传距离为14.2cM。将该片断回收、克隆、测序,表明其长度为878bp,该标记命名为OPP03878。根据测序结果,设计1对特异引物,进行特异性扩增,成功地将OPP03878标记转化为SCAR标记,用亲本及分离群体验证表明该分子标记稳定性好。更多还原

【Abstract】 The inheritance of resistance to sweetpotato stem nematode (Ditylenchus destructor) was analyzed in 174 progenies of the F1 single-cross population produced from the cross of resistant parent "Xu781" and susceptible parent "Xushu 18". Single hexasomic inheritance was proposed with genotype of resistant and susceptible parents represented as Rrrrrr and rrrrrr, respectively. Using bulk segregant analysis in combination with RAPD technique, 940 random decamer primers were screened, 10 of them showed polymorphic bands between the two bulk DNA samples. Primers detecting polymorphism between the two bulks were used to screen the parents and eight individuals from each of the bulks. The results showed that only primer OPP03 produced a specific band in the resistant plants but not in the susceptible plants, suggesting a marker linked to a gene for stem nematode resistance. The amplified analysis of the 174 F1 individuals indicated that the statistic genetic distance was 14.2 cM between the marker and the stem nematode resistance gene with Mapmaker 3.0. The fragment amplified by OPP03 was cleaned, cloned and sequenced, and was 878 bp in length, named OPP03878. This RAPD marker was successfully converted into sequence-characterized amplified region (SCAR) marker through the use of the specific primer pair designed from the sequence of the OPP03878. The SCAR marker showed high stability in the two parents and their segregation population.更多还原