关键词: 东亚, 第三纪孑遗植物, 亲缘地理学, 冰期避难所, 物种形成, 迁移

Abstract

In this review, based on recent studies of population genetics and phylogeographics of East Asia’s Tertiary relict plants, we have outlined the main phylogeographic patterns and processes. We also summarize common geographic and environmental factors which may contribute to the phylogeographic patterns of East Asia’s Tertiary relict plants and present future challenges and research prospects. There are four recurrent phylogeographic scenarios identified by different case studies, including: (1) the global cooling and aridification during the Middle and Late Miocene induced recent speciation, with climate change during the Late Pliocene and Pleistocene accounting for their intra-specific lineage divergence, genetic diversification and demographic expansion/contraction. The latitudinal contraction/expansion can lead to the formation of “suture zone” for some relict plants; (2) the effects of the formation of the glacial East China Sea land bridge, as a “corridor” or “filter”, have to account not only for habitat preferences per se but also for other biological features of different relict plant species; (3) the uplift of the Qinghai-Tibet Plateau (QTP) during the Late Pliocene and the intensification of East Asian monsoon system (EAMS) are the most suggestive factors responsible for the major phylogeographic break between the western and eastern lineages across the Sichuan Basin and northwestern arid regions; and (4) some Tertiary relict plants migrated southward to Taiwan from mainland China or Japan before the Pleistocene under global climatic cooling and aridification since the Late Miocene, and refugial isolation that occurred between Taiwan and mainland Asia accelerated vicariant lineage diversification and speciation. Overall, both historical and contemporary geography and environment have affected the distribution, genetic diversity, lineage divergence and speciation of East Asia’s Tertiary relict plants. Finally, we emphasize notable gaps in our knowledge due to the long-term application of simple molecular clock based on very limited genetic markers, and outline future research prospects for disentangling the evolution and biogeographic history of East Asia’s Tertiary relict flora. We present the utilization of genome data and biogeography models and integrative phylogeographic research of multi-taxon communities as possible future directions.

Key words: East Asia, Tertiary relict plants, phylogeography, glacial refugia, speciation, migration