Variation and evolution of sexual and asexual races in Mexican Stevia

墨西哥甜叶菊有性和无性种族的变异和进化

• 批准号: 12575010
• 负责人: YAHARA Tetsukazu
• 金额: $ 4.29万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12575010/
• 关键词: Sexual reproduction; Asexual reproduction; Sepciation; Evolutionary rate; ITS; Polyploidy; ステビア; 遺伝的変異

Mexica Stevia is represented by 99 species among which asexual races are found in 42 species. Among them, sexual races are mostly restricted to small area. However, S. origanoides is an interesting exception in which sexual and asexual races are widely distributed. We carried out transect studies in six area where sexual and asexual races of S. origanoides are found. As a result, we found that sexual populations in three area include cryptic species that are differentiated in morphological traits and habitat preferences. To examine whether these cryptic species differentiated in each area or in defferent area, we sequenced ITS for various samples of S. oritanoides. The results obtained seem to support the differentiation in each area, but resolution of the tree was not sufficient to be conclusive. Now, AFLP analysis is on going. The ITS tree showed that most of asexual triploids clustered together, indicating their monophyly. On the other hand, sexual populations of S. origanoides are differentiated to at least six cryptic species. These findings suggest that sexual reproduction is advantageous when populations are rapidly differentiating under spatially heterogeneous environments.

墨西哥甜叶菊以99种代表，其中有42种无性竞赛。其中，性种族主要仅限于小面积。但是，S。origanoides是一个有趣的例外，其中性和无性种族被广泛分布。我们在六个地区进行了横断研究，在这些区域中发现了s。origanoides的性和无性种族。结果，我们发现三个领域的性种群包括在形态特征和栖息地偏好中有区别的神秘物种。为了检查这些神秘的物种是在每个区域还是在缩减区域中分化的，我们将其测序为各种ofs。oritanoides样品。获得的结果似乎支持每个区域的分化，但是树的分辨率不足以结论性。现在，AFLP分析正在进行中。它的树表明，大多数无性三层三倍体都聚集在一起，表明它们是单性的。另一方面，S。Origanoides的性种群与至少六个神秘物种区分开。这些发现表明，当种群在空间异质环境下迅速区分人群时，性繁殖是有利的。

项目成果

Soejima A., Watanabe, K. & Yahara, T.: "Distribution and variation of sexual and agamospermous populations of Stevia from Mxico"Plant Species Biology. 16. 91-105

副岛 A.、渡边 K.

Soejima, A., Yahara, T., Watanabe, K.: "Distribution and variation of sexal and agamospermous populations of Stevia (Compositae : Eupatorieae) from Mexico"Plant Species Biology. 16. 91-105 (2001)

Soejima, A.、Yahara, T.、Watanabe, K.：“来自墨西哥的甜叶菊（菊科：Eupatorieae）有性和无子植物种群的分布和变异”植物物种生物学。

Watanabe, K., Yahara, T.ほか: "Mexican species of the genus Stevia : Chromosome numbers and geographical distribution"Plant Species Biology. 16. 49-68 (2001)

Watanabe, K., Yahara, T. 等人：“甜叶菊属的墨西哥物种：染色体数目和地理分布”植物物种生物学。 16. 49-68 (2001)

Soejima, A., Yahara, T.ほか: "Thirteen new species and two new combinations of Stevia from Mexico"Brittonia. 53. 377-395 (2001)

Soejima, A., Yahara, T. 等人：“墨西哥甜叶菊的十三个新品种和两个新组合”Brittonia. 53. 377-395 (2001)

Watanabe, K., Soejima, A. & Yahara, T.: "Mexican species of the genus Stevia : Chromosome numbers and geographical distribution"Plant Species Biology. 16. 49-68 (2001)

渡边，K.，副岛，A.