Testing Systematic and Evolutionary Hypotheses in a Primitive Neotropical Group of Violets (Viola sect. Leptidium)

真正的紫罗兰属于紫罗兰属，由一大群种类繁多的植物组成，这种植物在世界各地都有发现，但在拉丁美洲热带的山区尤为丰富。像许多其他热带植物群一样，拉丁美洲的代表很少受到科学上的关注。迫切需要研究来了解那里的物种多样性，澄清物种的差异并找出它们之间的关系，并最终阐明物种多样化的进化过程。首席调查员最近对拉丁美洲和世界各地其他紫罗兰族的分子研究表明，拉丁美洲紫罗兰是最古老和最原始的。因此，对这些紫罗兰的研究将揭示紫罗兰在世界各地的起源、进化、全球迁徙和显著的成功等重要线索。拉丁美洲最大的两个紫罗兰族之一，利普蒂亚组，是这项资助研究的重点。将对哥伦比亚和委内瑞拉，秘鲁和玻利维亚，以及巴西东南部进行实地考察，以研究所有种类的紫罗兰组的种群。并将开花和果实材料带回进行密集的实验室研究。花卉、树叶、胶囊和种子的细节将在实地采样的种群中进行比较，并与从其他植物机构借来的数千件博物馆藏品进行比较，以确定可识别的物种。每个物种的几个种群中每一个都有代表性的合成物将从实地考察中带回进行分子研究。两种类型的分子数据，核内转录间隔区的DNA序列和高度可变的简单序列间重复标记，将从种群样本中产生，以解释种群和物种之间的关系。从该组物种的花中提取的染色体数目和物种的物理特征，将与世界上其他紫罗兰组进行比较，以解释作为一个整体的“真正的”紫罗兰的进化模式。将完成对Leptidium部分物种的传统分类处理，以服务于在拉丁美洲遇到这些紫罗兰的植物学家和博物学家。

The "true" violets, belonging to the genus Viola, comprise a large and verydiverse group of plants that is found worldwide but is especially rich inthe mountain regions of the Latin American tropics. Like many othertropical plant groups, Latin American representatives have received littleserious scientific attention. Studies are desperately needed to understandspecies diversity there, clarify distinctions of species and figure outrelationships among them, and eventually to illuminate evolutionaryprocesses of diversification. Recent molecular studies of Latin Americanand other violet groups worldwide by the Principal Investigator demonstratethat Latin American violets are the oldest and most primitive of all.Thus, investigations on these violets will reveal important clues regardingthe origins of violets around the world, their evolution, global migrationand remarkable success. One of the two largest violet groups in LatinAmerica, section Leptidium, is the focus of the funded research.Field expeditions to Colombia and Venezuela, Peru and Bolivia, andsoutheastern Brazil, will be made to study populations of all species ofsect. Leptidium in the field and to bring back flowering and fruitingmaterials for intensive laboratory studies. Details of flowers, leaves,capsules and seeds will be compared among field-sampled populations, andagainst thousands of museum collections on loan from other botanicalinstitutions, to determine recognizable species. A compositerepresentative from each of several populations of each species will bebrought back from the field expeditions for molecular investigations. Twotypes of molecular data, DNA sequences from the nuclear InternalTranscribed Spacer region, and highly variable Inter-Simple Sequence Repeatmarkers, will be generated from the population samples to interpretrelationships between populations and species in section Leptidium.Chromosome numbers taken from flowers of species in the group, and physicalcharacteristics of species, will be compared with other groups of violetsaround the world, in order to interpret evolutionary patterns in the "true"violets as a whole. A traditional taxonomic treatment will be completedfor species in section Leptidium, to serve botanists and naturalists whoencounter these violets in Latin America.