Young dispersal of xerophil Nitraria lineages in intercontinental disjunctions of the Old World

Abstract

Many cases of intercontinental disjunct distributions of seed plants have been investigated, however few have concerned the continents of Eurasia (mainly Central Asia), Africa, and Australia, especially the xerophytic lineages are lacking. Nitraria (Nitrariaceae) is just one of these xerophytic lineages. Previous Nitraria studies have hypothesized either Africa as the ancient center, with dispersals to Australia and Eurasia, or alternatively Central Asia, due to a concentration of endemism and diversity there. Our findings show eastern Central Asia, i.e. the eastern Tethys, to be the correct place of origin. Dispersal westward to Africa occurred during the late Oligocene to Pliocene, whereas dispersal to Australia from western Central Asia was young since Pliocene 2.61 Ma. Two related tetraploids are indicated to have diversified in eastern Central Asia at approximately 5.89 Ma, while the Australian tetraploid N. billardieri, is an independently derived, recent dispersal from western Central Asia.

Sequential horizontal gene transfers from different hosts in a widespread Eurasian parasitic plant, Cynomorium coccineum

“…All Cynomorium hosts in the western part of the range are adapted to salty (water‐stressed) habitats and may physiologically resemble each other and the Asian desert species to which the parasite adapted originally. Whether Cynomorium reached the Mediterranean region from Asia via a northern route, similar to Halophyllum (Rutaceae; Manafzadeh et al., ), or via southern (Arabian Peninsula/African) route, similar to Nitraria (Zhang et al., ), or even both routes, is an open question, but there is definitely a deep split between Iberian plants and the remaining accessions (Appendix S4). In North Africa, Cynomorium may continue to parasitize Nitraria , which has one species there, N. retusa , but we were unable to find published reports of N. retusa being a host.…”

“…). The Mongolian deserts expanded following the Eocene retreat of the Parathetys between 47 and 37 Myr (Bosboom et al., ), and Cynomorium might have expanded westward during that time along with the Nitrariaceae, which have been inferred to have expanded from Asia to North Africa between 61 and 30 Myr (Zhang et al., ). A caveat with inferring the stem age of Cynomorium is that its sister relationships in the huge order Saxifragales are still unclear.…”

“…In the western part of its range, C. coccineum parasitizes mostly species from the Amaranthaceae subfamily Chenopodioideae (usually Atriplex or Salsola ), Plumbaginaceae (e.g., Limonium ), Tamaricaceae ( Tamarix ), and Frankeniaceae ( Frankenia ; all in the Caryophyllales), Cistaceae (Malvales), Fabaceae (Fabales), and Asteraceae (Asterales). In the easternmost part of its range (Afghanistan, Mongolia/China), it parasitizes mostly Nitrariaceae (Sapindales), including Peganum harmala and Nitraria , a genus of 8–12 species in Asia and the Mediterranean, Central Asian Tamaricaceae (genus Reaumuria ), Zygophyllaceae (genus Zygophyllum ), and Salsola as in the western part of its range (Teryokhin et al., ; Chen and Funston, ; Yang et al., ; Cui et al., ; Zhang et al., ).…”

Phylogeny and biogeography of Artemisia subgenus Seriphidium (Asteraceae: Anthemideae)

“…ex DC. and Clausia Trotzky [Brassicaceae]: Friesen & al., 2015;Nitraria L. [Nitrariaceae]: Zhang & al., 2015a). Indeed, Central Asia has been proposed to be the main source and centre of diversity of the current xerophytes of Eurasia, the Mediterranean Basin and North Africa (Manafzadeh & al., 2017 and references therein).…”

A review on the floristic phytogeography in arid northwestern China and Central Asia

“…植物区系的始生性质 (Wulff, 1964) Komarov, 1945;Wulff, 1964; 路 安 民 , Komarov (1908Komarov ( , 1947 (Nylander et al, 2008;Ree & Smith, 2008;Yu et al, 2015), 为区系地理研究提供了有效的方法, 在 一定程度上能够给出科属类群较确切的起源时间 和起源地点。虽然这些方法应用于干旱区植物类群 的研究并不多, 但也有一些典型的案例, 例如对蒿 属(Artemisia) (Miao et al, 2011)、锦鸡儿属 (Zhang et al, 2009(Zhang et al, , 2015bZhang & Fritsch, 2010)、白刺属 (Temirbayeva & Zhang, 2015;Zhang et al, 2015a)、木 蓼 属 (Atraphaxis) (Zhang et al, 2014b) 、 红 砂 属 (Reaumuria) (Zhang et al, 2014a …”