Phylogeny, Systematics and Evolution of Cactaceae, Subfamilies Opuntioideae and Cactoideae

仙人掌科、仙人掌亚科和仙人掌亚科的系统发育、系统学和进化

• 批准号: 9527884
• 负责人: Robert Wallace
• 金额: $ 5.5万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9527884&HistoricalAwards=false
• 关键词: Phylogeny; Systematics; Evolution; Cactaceae; Subfamilies

9527884 Wallace The cactus family, Cactaceae, comprises some 1500 species in North and South America (with one introduction to West Africa) and includes morphologically diverse life forms ranging from columnar, tree-like to barrel to viny and epiphytic. In adapting to dry and often desert conditions, these "stem succulents" have likely in parallel converged on similar vegetative shapes and forms, which renders evolutionary analysis designed to distinguish the lineages within the family difficult and confusing. In order to obtain robust and independent comparative data for taxonomic and phylogenetic analyses, Dr. Robert Wallace of Iowa State University is studying DNA variation in genes of the chloroplast and nucleus, from samples of cacti from the two large subfamilies Opuntioideae and Cactoideae. DNA nucleotide sequences are being gathered from several genes, and these will be aligned for comparison and assessed for mutational differences between species. Phylogenetic trees are then constructed based upon these measures of mutation difference. With the phylogenies (or taxon genealogies) as guide to lineage relationships among genera and species, one can study the pattern of adaptive radiation into desert habitats throughout the Americas, and the morphological changes that accompany or enable evolution into various regions and habitats. The phylogenetic analysis also will inform a more stable classification of cacti, and direct the choice of key characters for purposes of species identification.

9527884华莱士仙人掌是仙人掌科仙人掌科，在北美和南美洲约有1,500种(其中一种介绍到西非)，从柱状、树状到桶状到藤本植物和附生植物，形态多样。在适应干旱和通常是沙漠条件的过程中，这些“茎多肉植物”很可能平行地汇聚成类似的营养形状和形式，这使得旨在区分家族血统的进化分析变得困难和困惑。为了获得可靠和独立的分类和系统发育分析的比较数据，爱荷华州立大学的罗伯特·华莱士博士正在从仙人掌亚科和仙人掌亚科的样本中研究叶绿体和细胞核基因的DNA变异。目前正在从几个基因中收集DNA核苷酸序列，这些序列将进行比对，并评估物种之间的突变差异。然后基于这些突变差异的度量构建系统发育树。以系统发生学(或分类系谱)为指导的属和种之间的谱系关系，人们可以研究整个美洲沙漠生境的适应性辐射模式，以及伴随或允许进化到不同区域和生境的形态变化。系统发育分析还将提供更稳定的仙人掌分类，并指导用于物种鉴定的关键性状的选择。