番茄抗青枯病基因的AFLP分子标记

Identification of AFLP Markers Linked to Bacterial Wilt Resistance Gene in Tomato

用番茄高抗青枯病品种“T51A”与高感青枯病品种“T9230”配制杂交组合,接种鉴定其正反交F1代及F2代分离群体的青枯病发生情况。结果表明,T51A对青枯病的抗性属于细胞质遗传,受1对杂合基因加性控制。用64个EcoRⅠ/MseⅠ引物组合对“T51A”、“T9230”两个亲本及其F2代抗病和感病基因池进行AFLP分析,共扩增出约4200条可分辨的带,其中2条为稳定的差异。用“T51A”和“T9230”杂交产生的F2代分离群体对2个特异条带与目的基因的遗传连锁性进行分析,发现特异条带AAG/CAT与暂定名为RRS342的抗青枯病基因紧密连锁,二者之间的遗传距离为6.7cM。将AAG/CAT片段回收、克隆和测序,成功地将其转化为SCAR标记,可以更加方便地用于对番茄青枯病基因的标记辅助选择。

A cross between bacterial wilt resistant tomato variety “T51A” and susceptible variety “T9230” was made for mapping bacterial wilt resistance gene（s）. Through inoculation test of its F1 and Fz progeny, it was proved that the resistance of “T51A” to bacterial wilt was controlled by one heterozygous gene and cytoplasm. With 64 EcoRI/MseI primer combinations, AFLP analysis was performed on two parents and their F2 resistant and susceptible bulks. A total of about 4200 distinguishable bands were amplified, of which two were stable. Genetic linkage analysis of the two polymorphic DNA fragments with the resistance gene（s） was tested in the Fz segregating population derived from the cross between “T51A” and “T9230”. The DNA fragment AAG/CAT was found to be closely linked to one of the bacterial wilt resistant genes, with a genetic distance of 6.7 cM, that was tentatively named RRS-342. The cloned fragment AAG/ CAT was sequenced and then successfully converted to a SCAR marker, which can be used more conveniently in markerassisted selection for tomato resistance to bacterial wilt gene.