Multiple banding pattern, a potential problem of cross-species microsatellite amplilification, happened when EST-SSR primers of Porphyra yezoensis were used in microsatellite amplification for several lines of Porphyra haitanensis. These PCR products were sequenced to identify false positive amplification. Among the recovered products from P. haitanensis., bands with similar size to the amplification product of positive control from P. yezoensis contained the anticipated SSR. Sequence alignment showed high identity. The microsatellite signature was absent from the amplification products with bigger molecular weight. This result showed a typical false positive problem. Therefore primers that produced false positive products in P. haitanensis can not be used in those genetic analyses based on models of SSR mutation, such as the diploid conchocelia pure line test of P. haitanensis. However, they are still useful for the species identification and other genetic researches.%当条斑紫菜EST-SSR引物在坛紫菜几个品系上进行种间扩增时,微卫星引物的扩增结果中也出现了多带形式.为了研究的假阳性问题,扩增产物被从胶上回收克隆测序.在回收的坛紫菜扩增产物中,同阳性对照条斑紫菜扩增产物大小相同的产物中有微卫星序列重复,但在大分子量的条带中却没有,显现出典型的假阳性问题.在坛紫菜扩增中产生的假阳性带不适合进行建立在微卫星突变基础上的遗传研究,然而,在确定相关的遗传性状后,这些引物也可以用来进行品系鉴定等遗传研究.
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