基于ITS序列探讨空心瓜在葫芦科中的系统分类

The Taxonomic Classification of Praecitrullus fistulosus in Cucurbitaceae based on Internal Transcribed Spacer Sequences

空心瓜是葫芦科一年生草本植物,是葫芦科重要的抗性资源。然而,长期以来其系统分类不清,严重影响空心瓜的利用。空心瓜形态学观察结果发现,与冬瓜具有许多相似之处。随后克隆其ITS序列,并与葫芦科其他作物进行系统进化分析,结果发现,空心瓜与冬瓜的遗传距离仅为0.03,位于进化树同一个分支末端,这表明空心瓜归属于冬瓜属。本研究不仅为空心瓜的系统分类提供直接的分子证据,而且为利用空心瓜拓宽冬瓜种质资源奠定重要的研究基础。

Praecitrullus fistulosus is an annual Cucurbitaceae herb and it is an important resistant source in Cucurbitaceae. However, the systematic classification of P. fistulosus is unclear for a long time, which seriously affects its utility. Based on the morphological observation, author finds that there are many similarities between P. fistulosus and Benincasa hispida. Subsequently, this paper carries out phylogenetic analysis with other Cucurbitaceae species by clone the ITS sequence. The result showed that the genetic distance between P. fistulosus and B. hispida is only 0.03, and they locates in the same terminal branch of the phylogenetic tree. This indicates that P. fistulosus belongs to Benincasa. This study not only provides a more clear evidence for the classification of P. fistulosus, but also lays an important foundation for the utility of B. fistulosus to broaden B. hispida germplasm.