Study on the Origin and Classification of Two Poplar Species on the Qinghai–Tibet Plateau

Abstract

Poplar not only has important ecological and economic value, but also is a model woody plant in scientific research. However, due to the rich morphological variation and extensive interspecific hybridization, the taxonomy of the genus Populus is very confused, especially in the Sect. Tacamahaca. Based on the extensive investigation of Populus on the Plateau and its surrounding areas, two taxa (Populus kangdingensis and Populus schneideri var. tibetica) that are very similar in morphology and habitat and are in doubt in taxonomy were found. First of all, we set up 14 sample sites, carried out morphological investigation and statistics, and found that there were a few morphological traits that could be distinguished between the two taxa. Further phylogenetic analysis based on the whole genome resequencing data showed that the two taxa were hybrid progenies of P. xiangchengensis and P. simonii. Through gene flow detection and genetic differentiation analysis, it was found that there was still strong gene flow from P. xiangchengensis to the two taxa, and there was almost no differentiation between the two taxa. Therefore, P. schneideri var. tibetica should be classified into P. kangdingensis as same taxa. Finally, the population history was reconstructed by PSMC and ABC models, and it was found that they all belonged to a hybrid origin, and the change in population size was closely related to the Quaternary ice age. In addition, the hybrid population has better adaptability, and the suitable distribution area may expand in the future. This study provided a novel and comprehensive method for the phylogeny of Populus and laid a foundation for the development and utilization of poplar resources.

Unraveling the interplay between demography and landscape features in shaping connectivity and diversity: Insights from the leopard cat on a subtropical island

“…However, as no discernible population growth was identified during the hybridization events, we suggest that this secondary contact might imply geographic expansion rather than population growth, as previous studies have indicated that geographic expansion and population expansion may not always be correlated (Excoffier et al 2009;Williams & Giddings 1984). Furthermore, some studies have suggested that hybridization events can occur despite continuous declines in overall population sizes (Pellegrino et al 2015;Shi et al 2023). In our study, even if restrictions 200 years ago prevented humans from colonizing forests for about seven years, this timeframe may not have been sufficient for the forest system to recover.…”

An Overview of the Current Situation of European Poplar Cultures with a Main Focus on Hungary

“…All of these, together with the generally safe timber sales opportunities, made the production of hybrid poplars economical and profitable [4,5]. In addition, breeding has been going on all over Europe ever since [6,7], and poplars seem to be a good model for tree physiology and genomics research [8,9]. This shows that this issue is important across Europe and is still being addressed today. )…”

“…One major advantage of poplars and willows (Salix spp.) is that they have a relatively short cutting age, i.e., rotation time, to produce maximum yields of timber or fiber on a sustainable basis [8,9]. Taking into account their large volume, future poplar utilization should be based on an integrated and total use concept, i.e., produce the highest-value products or product combinations from each given raw material input so that nothing is wasted [17].…”