Ancient and modern introduction of <i>Broussonetia papyrifera</i> ([L.] Vent.; Moraceae) into the Pacific: genetic, geographical and historical evidence

<i>Broussonetia papyrifera</i> (L.) Vent. (Moraceae), or paper mulberry, is a species of cultural importance in South East Asia, East Asia and the Pacific. Originally from mainland South East Asia or East Asia, this plant was introduced into the Pacific range by prehistoric Austronesian voyagers. We used non-coding internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA and inter-simple sequence repeat (ISSR) on 79 samples of <i>B. papyrifera</i> from different islands of Remote Oceania, and South East Asia and East Asia. Our results show an absence of genetic diversity in the introduced range of Remote Oceania, with the sole exception of Hawaii. By contrast, Asian samples show genetic diversity. The data obtained suggest a prehistoric human-mediated introduction of this species from East Asia to Remote Oceania and a second, possibly historic, human-mediated introduction to Hawaii.构树（*Broussonetia papyrifera* (L.) Vent.，桑科Moraceae），又名纸桑，在东南亚、东亚及太平洋地区具有重要文化价值。该物种原产于东南亚大陆或东亚，经史前南岛航海族群的远洋活动被引入太平洋分布区。本研究对采自远大洋洲、东南亚及东亚不同岛屿的79份构树样本，开展了细胞核核糖体DNA非编码内转录间隔区（internal transcribed spacer，ITS）序列与简单序列重复区间扩增多态性（inter-simple sequence repeat，ISSR）分析。结果显示，除夏威夷群岛外，远大洋洲的引种种群几乎不存在遗传多样性；而东亚及东南亚的样本则展现出丰富的遗传多样性。本研究数据表明，该物种经史前人类介导从东亚传入远大洋洲，另有一次可能发生于历史时期的人类介导引种事件，将其引入夏威夷群岛。