Chloroplast DNA phylogeographic analysis reveals significant spatial genetic structure of the relictual tree Davidia involucrata (Davidiaceae)

Abstract

The dove tree, Davidia involucrata Baill. (Davidiaceae), is a relict species endemic to China. Human activities and the strict requirements for seedling recruitments have led to the decline in number of individuals in extant natural populations of this species. In order to provide information for the design of conservation management strategies for D. involucrata, we investigated the phylogeographical pattern of this relict tree. Our sampling included 256 individuals from 32 natural populations of D. involucrata in China and we sequenced six chloroplast DNA (cpDNA) non-coding regions. We distinguished a total of 13 different cpDNA haplotypes. From the cpDNA variation in D. involucrata, we found a very high level of regional differentiation (F ST = 0.812) and a strong phylogeographical pattern (N ST = 0.996 [ G ST = 0.981, P \ 0.05). Phylogenetic analysis reveals three main cpDNA haplotype lineages and four population groups. The split between these geographical groups can be dated back from the late Pliocene to early Pleistocene. Nonoverlapping distribution of chloroplast haplotypes and high genetic differentiation among four distinct geographical groups suggest that D. involucrata probably survives in four separate glacial refugia. Our findings have an important implication for conservation of its genetic diversity. The deduced glacial survival areas for D. involucrata should be recognized as four ''evolutionary significant units'' and be considered as separate targets in conserving its genetic diversity.

Evolution of East Asia’s Arcto-Tertiary relict Euptelea (Eupteleaceae) shaped by Late Neogene vicariance and Quaternary climate change

“…Cercidiphyllum spp. ; Tetracentron sinense ; Davidia involucrata ; Sargentodoxa cuneata ) [ 3 , 4 , 12 , 104 ]. However, our estimated coalescent times of the various cpDNA phylogroups within E. pleiosperma (nodes C1 and C2: 1.66 Ma; C3: 1.15 Ma; C4: 1.73 Ma) and E. polyandra (node J1: 1.50 Ma; J2: 2.31 Ma) are generally more recent (Fig.…”

“…Nonetheless, recent molecular phylogeographic studies suggest that most Arcto-Tertiary relicts endemic to China have been little affected by Quaternary glacial-interglacial alternation [ 4 , 11 , 12 ]. In those instances, species likely tracked their climatic niche boundaries locally through altitudinal migration in a topographically complex landscape [ 13 – 15 ].…”

Population genetic structure, migration, and polyploidy origin of a medicinal species Gynostemma pentaphyllum (Cucurbitaceae)

“…A species with low genetic diversity lacks the evolutionary flexibility to cope with a changing ecological environment and is passive in longer-term evolutionary processes (Genton, Shykoff, & Giraud, 2005). Thus, a species with low level of genetic diversity is relatively more vulnerable to get extinction (Chen et al, 2015;Knox, Bezold, Cabe, Williams, & Simurda, 2016;Nolan, Noyes, Bennett, Hunter, & Hunter, 2010). In contrast, a high level of genetic diversity tends to be associated with successful ecological adaptation (Ortego, Noguerales, Gugger, & Sork, 2015).…”

Cytotype Distribution and Chloroplast Phylogeography of Actinidia Chinensis Complex

“…Among them, the chloroplast genetic diversity (H T ) of var. chinensis was 0.920, which was signi cantly higher than that the relict plants in this region, such as Cercidiphyllum japonicum (0.757) [44], Davidia involucrata (0.882) [45], and eupleea pleiosperma (0.893) [46]. However, the genetic diversity (H T ) of var.…”