Reconstructing Hybrid Speciation in Paeonia Section Paeonia by Phylogenetic Analyses of Adh Gene Sequences

通过对芍药Adh基因序列的系统发育分析重建芍药杂交物种形成本研究将探索单拷贝或低拷贝核基因系统发育分析的新途径，以重建芍药物种形成中的杂交事件。大量的植物物种被认为是杂交起源，目前对网状进化结果的检测和分析存在困难。由于这些原因，桑博士的研究应该对其他生物群体的研究有广泛的应用。牡丹（Paeonia, Paeoniaceae）在希腊被称为“草药女王”，在中国被称为“花之王”，已有一千多年的历史，是一种具有观赏和药用价值的植物。该属中最大的部分，Paeonia部分，由大约27个草本物种组成，广泛分布于东亚至地中海地区，主要由于该部分内复杂的杂交而在分类上存在问题。桑博士选择使用在假定的非杂交品种芍药切片中鉴定出的单拷贝数或低拷贝数乙醇脱氢酶基因序列（Adh1A和Adh2）作为分子标记。对于假定的杂交物种，每个位点的等位基因将通过位点特异性PCR引物扩增，克隆和测序。这些序列将与非杂交物种的序列进行系统发育分析。如果维持和克隆亲本等位基因，系统发育分析应该提供亲本谱系关系的精确重建，染色体数目（倍性水平）和分类上重要性状的变化，如小叶的解剖程度、雄蕊盘的长度、萼片的数量和形状、花冠形状、每茎花的数量和根的形状可以追踪。计划在法国、意大利、西班牙、土耳其和高加索山脉开展实地工作，收集新的植物材料。准确的系统发育重建和对牡丹花段形态演化的更好理解，将有助于牡丹花更好的分类。

9726838 Sang Reconstructing hybrid speciation in Paeonia section Paeonia by phylogenetic analyses of Adh gene sequences This research will explore a new approach, phylogenetic analysis of single or low copy nuclear genes, to reconstruct hybridization events in speciation in the section of peonies. Large numbers of plant species are suggested to be of hybrid origin, and currently there is difficulty in detecting and analyzing results of reticulate evolution. For these reasons Dr. Sang's study should have broad applications for the study of other organismal groups. Peonies (Paeonia, Paeoniaceae), known as "queen of herbs" in Greece and "king of flowers" in China for over a thousand years, are ornamentally and medicinally valuable plants. The largest section of the genus, section Paeonia, consisting of approximately 27 herbaceous species distributed widely from eastern Asia to the Mediterranean region, has been taxonomically problematic due primarily to complex hybridization within the section. Dr. Sang has chosen to use single or low copy number alcohol dehydrogenase gene sequences(Adh1A and Adh2) identified in putative non-hybrid species of section Paeonia as molecular markers. For the putative hybrid species, the alleles of each locus will be amplified by locus specific PCR primers, cloned, and sequenced. The sequences will be aligned with those of the non-hybrid species for phylogenetic analyses. If the parental alleles are maintained and cloned at each locus from a hybrid, phylogenetic analyses should provide a precise reconstruction of relationships of the parental lineages, and changes in chromosome numbers (ploidy levels) and taxonomically important characters such as degree of dissection of leaflets, length of staminodial disks, number and shapes of sepals, corolla shapes, number of flowers per stem, and root shapes can be traced. Field work to collect new plant material is planned in France, Italy, Spain, Turkey, and the Caucasus Mountains. An accurate phylogenetic re construction and a better understanding of morphological evolution of section Paeonia will permit a better classification of peonies.