中文摘要：

【目的】揭示HbSUT3的分子进化特点，及其与产量的相关性。【方法】克隆获得橡胶树5个大规模推广品种、9个1981’IRRDB野生种质和7个橡胶树属其它种或变种共计21份材料的HbSUT3及其同源基因（统称为SUT3）的cDNA序列，以及其中10个材料的基因组序列，利用MEGA软件（版本4．02）对获得的序列进行基因序列分析，并采用NJ法构建分子进化树。【结果】橡胶树属不同材料的SUT3均由4个外显子和3个内含子组成，其cONA编码区长度均为1608bp；不同材料序列的转换／颠换比均小于2．0，Ks值普遍大于Ka值；系统进化分析显示，高产的橡胶树种质趋于聚为一类，但橡胶属不同种的材料也可以聚在一起。【结论】橡胶树HbSUT3是一个进化相对保守的基因，其分子进化与橡胶树产量性状有一定的相关性，橡胶树属内的不同种和变种可能属于一个物种综合。

英文摘要：

[Objective] The purpose of this work was to investigate the molecular evolution of HbSUT3 and its correlation with latex yield. [Method] In this study, 21 cDNAs and 10 genomic DNAs of HbSUT3 and its homologs were cloned from 21 Hevea samples, including five large-scale recommended H. brasiliensis varieties, nine H. brasiliensis 1981＇ IRRDB germplasms, and seven other Hevea species. Molecular evolution analysis of these sequences was made mainly by using MEGA sottware, and the phylogenetic trees were constructed by the neighbor-joining algorithm. [Result] The results showed that the genomic clones of all HbSUT3 and its homologs contained four exons and three introns, and all had a cDNA coding sequence of 1 608 bp. The ratios of transitions to transversions between different samples were lower than 2.0, and the values of Ks were generally larger that those of Ka for maximum. Phylogenetic tree showed that high-yielding H. brasiliensis samples tended to cluster together, but samples of several Hevea species could also be grouped together. [Conclusion] Hb＇SUT3 and its homologs are evolutionally conservative, and the molecular evolution of HbSUT3 has a correlation with latex yield. In addition, the evolutionary analyses provide molecular evidence for the idea that the genus Hevea can be considered as species complex.