沙冬青属植物叶绿体基因组对比和系统发育分析

该研究以沙冬青和矮沙冬青叶绿体基因组为研究对象，比较分析其基因组结构和系统发育关系。结果显示: (1)沙冬青和矮沙冬青的叶绿体基因组具有典型的四段式结构，全长为153 935 bp和154 140 bp，其中大单拷贝区(LSC)分别为83 891 bp和84 126 bp，小单拷贝区(SSC)分别为18 022 bp和18 014 bp，以及长度各自为26 011 bp和26 000 bp的成对反向重复区(IRs)；沙冬青和矮沙冬青均注释130个基因，包括85个蛋白编码基因(PCGs)，37个转运RNA(tRNA)以及8个核糖体RNA(rRNA)。(2)沙冬青和矮沙冬青的叶绿体基因组中分别检测出26和15个回文重复序列，39和50个串联重复序列，23和34个散在重复序列。同时都鉴定出96个SSRs位点，包括74和73个单核苷酸重复，5和6个二核苷酸重复，以及各有17个复合SSR位点；边界分析显示两者IR区相似，但仍有一定差异。(3)通过近邻结合法(NJ)对沙冬青和矮沙冬青在内的17种蝶形花亚科以及2种云实亚科植物的叶绿体基因组构建的系统发育树显示，沙冬青和矮沙冬青以较高的支持率聚为一个独立分枝。该研究结果为沙冬青属的种间鉴别、SSR分子标记开发、保育工作、种群动态以及进一步研究坡塔里族的演化过程奠定了理论基础。

Comparative Analysis and Phylogenetic Evolution of the Complete Chloroplast Genome of Ammopiptanthus

In this study, the chloroplast complete genomes of Ammopiptanthus mongolicus and Ammopiptanthus nanus were used as research objects, and their genomic structure and phylogenetic relationship were compared and analyzed. The results showed that: (1) the chloroplast genomes of A. mongolicus and A. nanus have a typical four segment structure, with total length of 153 935 and 154 140 bp. Among them, the large single copy region (LSC) is 83 891 and 84 126 bp, and the small single copy region is 18 022 and 18 014 bp (SSC), respectively. The pair of inverted repeat regions (IRs) with lengths of 26 011 and 26 000 bp, respectively. The chloroplast genomes of A. mongolicus and A. nanus have annotated 130 genes, including 85 protein coding genes, 37 tRNA genes and 8 rRNA genes. (2) 26 and 15 palindromic repeats, 39 and 50 tandem repeat, 23 and 34 dispersed palindromic repeats were detected in the chloroplast genomes in the two species. At the same time, 96 SSRs were identified in the chloroplast genomes of A. mongolicus and A. nanus, of which 74 and 73 were mononucleotides, 5 and 6 were dinucleotides, and 17 were compound SSR. Boundary analysis shows that the IR region between A. mongolicus and A. nanus is similar, but there are still some differences. (3) A phylogenetic tree was constructed from the chloroplast genomes of 17 species of Papilionoideae, and 2 species of Caesalpinioideae, using the neighbor joining method (NJ). The phylogenetic tree showed that A. mongolicus and A. nanus were clustered into independent branches with higher support. This study provides a theoretical basis for further studies on interspecific identification, development of SSR molecular markers, conservation work, population dynamics, and further study of the evolution process of the Trib. Podalyrieae.