Molecular phylogeny and comparative ecology of Mexican Stevia

墨西哥甜叶菊的分子系统发育和比较生态学

基本信息

批准号：
07041129
负责人：
YAHARA Tetsukazu
金额：
$ 5.7万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Mexican Stevia includes about 100 species of annual, perennial, and shrubs among which shurubby species are considered to be ancestral. Floral morphology is diversified among species. Autogamy and apomixis are found in many species. Chromosome numbers vary from n=11 to n=12.The goal of this project is to examine correlation in generation time, reproductive system, floral morphology and chromosome numbers. To obtain research materials, we carried out field trips in Mexico.In 1995, we had field trips in Oaxaca, Veracruz, Jalisco and some other states. We collected about 50 species of Stevia including Stevia phlebophyla and S.karwinskyana which had never been collected during the past hundred years and had been considered to be extinct. We also found several new species. In 1996, we had field trips to Chiapas, Chihuahua, Durango and some other northern states. As a result of field trips during the two years, we obtaiened materials of approximately 80 species of the 100 total. Chromosome counts made on these materials revealed that shrubby species have n=12, perennial species have n=12 or 11, and annual species have n=11 or 4 (in S.ephemera). This fact supports the idea that chromosome number reduction is associated with reduction in generation time. All materials of shrubs and annuals examined were sexual diploids while perennial plants are often triploids, tetraploids or pentaploids and are regarded as seed apomicts.As a result of a phylogenetic study using sequences of matK,Carphocaete (n=12) was shown to be a sister genus of Stevia. Another study using sequences of ITS revealed that shurubby species (n=12) are monophyletic and basal in the genus ; perrenial species belong to two monophyletic groups, one of which includes S.deltoidea (n=12) and S.decummbens (n=12), and the other includes some species with n=11 and S.origanoides (n=11,12).

墨西哥甜叶菊包括大约100种年度，多年生和灌木，其中Shurubby物种被认为是祖先。花卉形态在物种之间多样化。在许多物种中都发现自动型和apomixis。染色体数量从n = 11到n = 12不等。该项目的目的是检查生成时间，生殖系统，花卉形态和染色体数的相关性。为了获得研究材料，我们在墨西哥进行了实地考察。在1995年，我们在瓦哈卡州，韦拉克鲁斯，哈利斯科州和其他一些州进行了实地考察。我们收集了大约50种甜叶菊，其中包括甜叶菊和s.karwinskyana，它们在过去一百年中从未收集过，被认为已灭绝。我们还发现了几种新物种。 1996年，我们进行了前往Chiapas，Chihuahua，Durango和其他一些北部州的实地考察。由于在两年内实地考察的结果，我们获得了100个总计约80种的材料。这些材料上的染色体计数表明，灌木种具有n = 12，多年生物种的n = 12或11，并且年度物种的n = 11或4（在s.ephemera中）。这一事实支持这样的想法：染色体数量减少与减少发电时间有关。所检查的灌木和一年生的所有材料均为性二倍体，而多年生植物通常是三倍体，四倍体或五倍体植物，被视为种子植物。由于使用MATK序列，Carphocaete（n = 12）的系统发育研究的结果是Stevia的姐妹属。另一项使用其序列的研究表明，shurubby物种（n = 12）在该属中是单系的，基础是基础。多肾种类属于两个单系组，其中一个包括s.deltoidea（n = 12）和s.decummbens（n = 12），另一个包括一些n = 11和s.origanoides（n = 11,12）的物种。