摘要
利用小麦抗白粉病基因Pm21的RAPD标记（OPH17（1400））、SCAR标记（SCAR（1400）和SCAR（1265））和荧光原位杂交技术（FISH）对小麦抗病育种材料中的抗白粉病Pm21基因进行了分子鉴定和标记辅助选择。利用随机引物OPH17进行RAPD分析结果表明，在3～5次重复共372次RAPD扩增中，有28次（7．53％）未获得扩增产物，有21次（5．64％）扩增结果难以判断目标片段OPH17（1400）的有无，说明RAPD标记检测结果的可靠性和重现性较差，在育种中应用有一定局限性。而在利用SCAR标记共488次PCR扩增中，均可以扩增出与Pm21基因连锁的多态性SCAR（1400）或SCAR（1265）目标片段，说明SCAR标记是稳定、准确、可靠的DNA分子标记，可应用于育种群体中Pm21基因的分子鉴定和标记辅助选择。利用RAPD和SCAR标记对具有不同遗传背景的"滚动式加代回交转育"抗白粉病育种群体中抗病基因Pm21分子标记检测结果表明，DNA分子标记与植株的白粉病抗性表现一致，并在此基础上进行了标记辅助的向农艺亲本的回交转育。荧光原位杂交结果表明，经多代回文改良，未发现簇毛麦6VS染色体臂与普通小麦染色体的重组。
RAPD marker (OPH17(1400)) and SCARmarkers (SCAR1400 and SCAR(1265)) as well as fluorescence in situ hybridization (FISH) technique were used to detect wheat powdery mildew resistance gene Pm21 derived from Haynaldia villosa (6AL/ 6VS) in different genetic background of wheat breeding program. Among a total of 372 RAPD amplification reactions, 28 reastions (7.53%) yield no ampliflcation products, and the amplification products of 21 reactions (5.64%) were difficult to interpret the presence or absence of the OPH17(1400), indicating that RAPD marker OPH17(1400) is less reproducible and reliable, so that its usage in breeding program is limited. However, SCAR markers, SCAR(1400) and SCAR(1265), were amplified in all 488 PCR reactions, suggesting that SCAR markers are highly reproducible and reliable, and can be used in breeding Program. The specific SCAR(1265) made it possible to screen a large number of genotypes reliably and rapidly in practical breeding programs for the presence/absence detection between the resistant and susceptible plants. After backcrossed with common wheat lines for several bines, no recombination between the 6VS chromosome of Haynaldia villosa and any of the wheat chromosomes was detected by using FISH.
基金
国家自然科学基金!39670508
