利用trnL intron序列分析低等金縷梅類植物分子親緣

Abstract

測定分布於東亞的低等金縷梅類植物6科10個代表種的tmL(UAA) intron DNA序列，期以界定低等金縷梅類植物的分子親緣關係。以木蘭科鵝掌楸屬(Liriodendron)及烏心石屬(Michelia)為外群分析峙，獲得一個最近鄰的樹型圖及四個最儉約的樹型圖，其中最儉約的步長為418，其CI值與RI值分別為0.832及0.792。從trnL ( UAA) intron基因樹的結果顯示：1.領春木科與法國梧桐科聚在一起；2.昆欄樹科和水青樹科關係較近，後者應併入前者；3.達香樹科與金縷梅科關係較近，應置於金縷梅科內。我們的結果推論這些由古老、孤立的科別所組成的低等金縷梅類植物應為異質類群(heterogeneous group)。

The trnL (UAA) intron sequences of ten representative species from six families of the lower Hamamelidae were detelmined and used for the phylogenetic analysis. Cladistic analyses supported the paraphyly of lower Hamamelidae, rooted at Liriodendron and Michelia of Magnoliaceae. One neighbor-Joining tree and four most parsimonious trees were obtained. All of the parsimonious trees have 418 steps with CI and RI values of 0.832 and 0.792, respectively. The result draws the conclusions: 1. The Eupteleaceae shows a close relationship with the Platanaceae. 2. Trochodendraceae and Tetracentraceae are very close as indicated by a bootstrap value of 100%. 3. The Cercidiphyllaceae is most closely related to Hamamelidaceae, suggesting that Cercidiphyllaceae be placed in the Hamamelidales. Our result suggests that the lower Hamamelidae which consists of isolated ancient families are a heterogeneous group.