关键词: 甜瓜, EST-SSR, 信息, 标记

Abstract: A total of 35 547 melon ESTswere 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 215 ×107 bp. From these sequences, 2 877 SSRs were sought out, distributing in 2 119 ESTs. The frequency of the EST2SSRs was 8.36% and mean distance was 8.72 kb in 34 408 ESTs. Mononucleotide, 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, dinucleotide and trinucleotide, accounting for 15.88% , 16.02% and 28.61% , respectively. The frequency of the EST2SSRswith a repeat number of 4 -10 was 69.10% and 51.34% of them had a length of 12 - 20 bp. Thirty p rimer pairswere designed for partial EST-SSRs and used for PCR amp lification of 33 melon inbred lines. Among the p rimer 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 p rimer pairs, 19 pairs could be transferable to cucumber and 16 pairs to watermelon and 15 pairs to gourd. All these results indicated that exp loitation of SSR markers from melon ESTs was convenient and p racticable.

Key words: melon, Cucumis melo L., EST2SSR, information, marker