摘要
对GenBank中35547条甜瓜EST进行净化处理,得到总长度为2.5×107bp的无冗余EST34408条。从这些序列中发现2877个SSR,分布于2119条EST中,出现频率为8.36%,分布密度为1/8.72kb。单碱基、二碱基和三碱基重复是主导重复类型,分别占EST-SSR总数的16.61%、22.49%和46.09%。A/T、AG/CT和AAG/CTT分别是单碱基、二碱基和三碱基的优势重复基元,分别占15.88%、16.02%和28.61%。在所有的EST-SSR中,69.10%的重复次数为4～10次,51.34%的长度为12～20bp。设计了30对EST-SSR引物,分别对33份甜瓜自交系进行了PCR扩增,24对引物能够扩增出期望长度的条带,22对引物产物表现多态性,平均每对引物能检测到2.73个等位基因。这些引物能比较准确地将甜瓜材料聚为不同类别。24对引物中,有19对、16对和15对分别在黄瓜、西瓜和葫芦中通用。以上结果说明,从甜瓜EST中开发SSR标记是一条简便、可行的途径。
A total of 35 547 melon ESTs were downloaded from GenBank （http： //www. ncbi. nlm. nih. gov） and cleaned resulting in production of 34 408 non-redundant ESTs with a total length of 2.5 × 10^7 bp. From these sequences, 2 877 SSRs were sought out, distributing in 2 119 ESTs. The frequency of the EST-SSRs was 8.36% and mean distance was 8.72 kb in 34 408 ESTs. Mononueleotide, dinucleotide and trinucleotide repeats were major types, respectively accounting for 16.61% , 22.49% and 46. 09%. A/T, AG/CT and AAG/CTT were most frequent motifs in mononucleotide, dinueleotide and trinucleotide, accounting for 15.88% , 16. 02% and 28.61% , respectively. The frequency of the EST-SSRs with a repeat number of 4 - 10 was 69.10% and 51.34% of them had a length of 12 - 20 bp. Thirty primer pairs were designed for partial EST-SSRs and used for PCR amplification of 33 melon inbred lines. Among the primer pairs, 24 pairs gave distinct bands with expected length and 22 pairs generated polymorphic bands with 2.73 alleles per primer pair. With the primers, melon materials could be exactly divided into different groups, which accorded with the actual situation of the materials. Among the 24 primer pairs, 19 pairs could be transferable to cucumber and 16 pairs to watermelon and 15 pairs to gourd. All these results indicated that exploitation of SSR markers from melon ESTs was convenient and practicable.
出处
《园艺学报》
CAS
CSCD
北大核心
2009年第4期513-520,共8页
Acta Horticulturae Sinica
基金
国家‘863’计划项目(2007AA10Z100)
河南农业大学博士启动基金项目(30400247)
关键词
甜瓜
EST-SSR
信息
标记
melon
Cucumis melo L.
EST-SSR
information
marker
