中文摘要：

乙烯受体基因ETR1是乙烯信号转导过程中的关键调控基因。研究根据ETR1基因的保守序列设计引物,以西瓜（Citrullus lanatus（Thunb.）Matsum＆amp;Nadai var.lanatus）和黄瓜（Cucumis sativus L.）的基因组DNA为模板进行PCR扩增,获得序列长度分别为1 633 bp和1 491 bp的基因片段CLETR1和CSETR1。序列分析表明,CLETR1和CSETR1与Genebank中收录的多条ETR1基因的核苷酸序列同源性在80%～98%,氨基酸序列同源性在75%～98%。西瓜和黄瓜ETR1基因片段的编码序列存在明显的单核苷酸变异,共23个核苷酸位点存在SNPs（Single nucleotide polymor-phisms）,其中5个SNPs导致4个编码氨基酸的改变。

英文摘要：

ETR1 was the controlling gene in ethylene signal transduction.A pair of oligo nucleotide primers were designed from conserved domain of ETR1 gene family.PCR amplifications were performed on genomic DNA template of Citrullus lanatus（Thunb.） Matsum ＆amp; Nadai var.lanatus and Cucumis sativus L.,they produced two fragments of 1 633 bp and 1 491 bp,named CLETR1 and CSETR1 respectively.The results of Blastn on NCBI Genebank database indicated that many highly matched homologous nucleic acid sequences and amino acid sequences were all ethylene receptor gene,the ratio were 80% -95% and 75% -90% respectively. The single sequences between CLETR1 and CSETR1 , there were 23 SNPs（single and 5 of them resulted 4 amino acids difference. nucleotide variations were found in the conserved nucleotide polymorphisms） in the encoding region,