【摘要】 为了进一步利用现有的西洋参EST-SSR资源,从NCBI公共数据库中下载了4988条西洋参EST,全长为2616.042 kb。含SSR的EST序列313条,共349个SSR,平均每相隔7.5 kb出现1个SSR。SSR出现的频率和平均长度分别为7.00%和24.4 bp。在1~6 bp的重复基元中,三核苷酸重复基元出现频率最高,为34.09%;其次为二核苷酸重复基元和单核苷酸重复基元,分别为32.09%和21.78%。出现最多的重复基元为A/T(20.9%),其次是AT/TA(16.9%)。结果显示,西洋参的EST数据库中SSR序列出现频率较高,类型较丰富、多态性较高,根据西洋参EST建立其EST-SSR标记是一条简便而又有效的途径。更多还原

【Abstract】 To further utilize the EST-SSR resources of ginseng,4988 ESTs of Panax quinquefolium L.in the database of NCBI were downloaded and analyzed,which had a length of 2616.042 kb on total.Among them,there were 313 ESTs sequences containing 349 EST-SSR,which amounted to 7.00 % of the all ESTs sequence population.The average length and distribution distance of the EST-SSRs were about 24.4 and 7.5 kb,respectively.Among the different motifs ranging from 1 to 6 bp,trinucleotide repeats were most abundant,it was 34.09 %,followed by dinucleotide repeats and mononucleotide repeats,which were 32.09 % and 21.78 %.Among all identified motif types,A/T had the high EST frequency(20.9 %),followed by AT/TA,which was 16.9 %.The results indicated that,the SSR sequence had higher frequency from EST database of Panax quinquefolium L.,the type abundant and the polymorphism to be high.According to the EST of Panax quinquefolium L.,building EST-SSR marker is a effective way.更多还原