Effects of Microbial Communities on Elevational Gradient Adaptation Strategies of Pinus yunnanensis Franch. and Pinus densata Mast. in a Mixed Zone

Abstract

Pinus densata Mast. is considered a homoploid hybrid species that originated from the putative parent species Pinus tabuliformis Carr. and Pinus yunnanensis Franch., but the mechanism of the adaptive differentiation of P. densata and its parents in native habitats has not been reported. Therefore, the overlapping distribution areas between P. densata and P. yunnanensis in the heart of the Hengduan Mountains were chosen. The adaptive differentiation mechanism of the homoploid hybrids and their parents with respect to the elevational gradient was studied based on the morphological features and the different strategies of recruiting endophytic microbial communities from the rhizosphere soil. The results showed that (1) the height and diameter at breast height were the greatest at 2600 m and 2900 m, and from 2700 m to 2900 m, three-needle pines (P. yunnanensis-like type) transitioned into two-needle pines (P. densata-like type). (2) The recruitment of rhizosphere microbial communities was driven by the C, N, P and pH values which showed significant elevation features. (3) There was a significant difference in the recruitment strategies of endophytes between the P. yunnanensis-like type and P. densata-like type. Pinus densata mainly reduced the recruitment of Mucoromycota (fungi) and increased the recruitment of Proteobacteria (bacteria), which may be related to environmental adaptability, quorum sensing and the metabolism of auxiliary factors and vitamins at high elevations. (4) The root endophytic microbiome was enriched in the rare groups from the rhizosphere soil microbial pool. The results of this study provide new insights and new ideas for environmental adaptability and differentiation in homoploid hybrid speciation.

Diversity and Recruitment Strategies of Rhizosphere Microbial Communities by Camellia fascicularis, a Plant Species with Extremely Small Populations in China: Plant Recruits Special Microorganisms to Get Benefit out of Them

“…The results showed that the composition of rhizosphere soil and root endophytes were significantly different. In agreement with most of the literature, the results show that the endophytes were not simply random or changed according to the rhizosphere soil microbial pool gradient, but were actively recruited [34,35]. The composition of soil microorganisms was consistent with previous reports.…”

Soil Properties and Forest Decline in the North-Western Part of Romania

“…Another factor that impacts soil quality and health is soil erosion, which can have detrimental effects on forest productivity due to the loss of soil water and nutrients [8,9].…”

“…As environmental conditions shift along elevation gradients, plant hosts may need to adapt and recruit different microbial symbionts to maintain their symbiotic relationships. The availability and composition of microbial symbionts may vary with elevation due to the altered soil characteristics and associated microclimatic conditions [8].…”