Evolutionary history of a widespread tree species Acer mono in East Asia

Abstract

East Asia has the most diverse temperate flora in the world primarily due to the lack of Pleistocene glaciation and the geographic heterogeneity. Although increasing phylogeography studies in this region provided more proofs in this issue, discrepancies and uncertainty still exist, especially in northern temperate deciduous broad-leaved and coniferous mixed forest region (II). And a widespread plant species could reduce the complexity to infer the relationship between diversity and physiographical pattern. Hence, we studied the evolution history of a widespread temperate tree, Acer mono, populations in region II and the influence of physiographic patterns on intraspecific genetic diversity. Analyses of chloroplast sequences and nuclear microsatellites indicated high levels of genetic diversity. The diversity distribution was spatially heterogeneous and a latitudinal cline existed in both markers. The spatial distribution pattern between genetic diversity within A. mono and the diversity at species level was generally consistent. Western subtropical evergreen broad-leaved forest subregion (IVb) had a unique ancient chloroplast clade (CP3) and a nuclear gene pool (GP5) with dominance indicating the critical role of this area in species diversification. Genetic data and ecological niche model results both suggested that populations in region II disappeared during the last glacial maximum (LGM) and recovered from south of Changbai Mt. and the Korean Peninsula. Two distribution centers were likely during the LGM, one in the north edge of warm temperate deciduous broad-leaved forest region (III) and another in the south edge of region III. This was reflected by the genetic pattern with two spatially independent genetic groups. This study highlights the key role of region III in sustaining genetic diversity in the northern range and connecting diversity between southern and northern range. We elucidated the diversity relationship between vegetation regions which could facilitate the understanding of biodiversity origin and maintenance in East Asia.

Sharp genetic discontinuity in the aridity‐sensitive Lindera obtusiloba (Lauraceae): solid evidence supporting the Tertiary floral subdivision in East Asia

“…Both the TMRCA of chlorotypes and the NEA–SEA population divergence time of the nSSRs were estimated to be in the late Pliocene. The NEA–SEA divergence time of L. obtusiloba is similar to or younger than that in other tree species with similar distributions, in which divergence typically dates back to the late Miocene (Qi et al ., ; Guo et al ., ; Bai et al ., ; Cao et al ., ). Because neither the Bayesian method nor the ABC procedure considers gene flow during divergence, the estimated divergence time might be later than the true value.…”

“…Moreover, some species show no clear NEA–SEA genetic divide. For example, a genetic division in Acer mono was found along the arid belt on the mainland (Guo et al ., ), whereas populations on the Japanese archipelago were more closely related to those in SEA (Ye et al ., ), and an ambiguous pattern has been found in some other species (Chen et al ., ; Qi et al ., ; Sakaguchi et al ., ). The arid belt narrowed and became less arid after a monsoon climate dominated at the Oligocene–Miocene boundary (Guo et al ., ), and NEA and SEA are now < 1000 km apart.…”

Combining mitochondrial and nuclear genome analyses to dissect the effects of colonization, environment, and geography on population structure in Pinus tabuliformis

“…This mountain range has become a significant physical obstacle for the northward movement of the seasonal monsoon since the late Miocene, and it created an important climate boundary that resulted in a warm‐humid subtropical climate to the south of the mountain range and a cool‐dry temperate climate to the north (Rost, ). In addition, the Qinling Mountains also function as a strong barrier to the dispersal of pollen and seeds, thus defining the phylogeography of many plant species in central China (e.g., Guo et al., ; Tian et al., ; Yuan et al., ).…”

Efficient Identification of the Forest Tree Species in Aceraceae Using DNA Barcodes

“…However, many maple species have complex sex systems, and since seeds and pollen are dispersed by wind and birds, interspecific hybridization and introgression occur extensively between closely related species, causing transitional intraspecific morphological variations, such as similar shapes of leaves, inflorescences and samaras (Guo et al, 2014; Liu C. et al, 2014). Therefore, it is difficult to recognize and delimitate maple species accurately by available morphological characteristics (Tian et al, 2002).…”