Abstract
Purpose of this study was to investigate different morphological and physiological responses of two species of Sect. Tacamahaca Spach, Populus kangdingensis C. Wang et Tung ( P. kangdingensis) and Populus cathayana Rehder ( P. cathayana), to exogenous abscisic acid (ABA) application under well-watered and water-stressed conditions and to further elucidate the role of ABA in drought tolerance. P. kangdingensis and P. cathayana possess different natural habitats in the eastern Himalaya; the first one occurs at high-altitude zone and the second one at low-altitude zone. Exogenous ABA was applied to the leaves by spraying, changes in plant growth and structure, gas exchange, endogenous ABA content and carbon isotope composition ( δ 13 C ) were measured. The results demonstrated that exogenous ABA application significantly decreased height growth (Ht), total biomass (Tb), total leaf area (La), specific leaf area (Sla), net photosynthesis ( A), transpiration ( E) and stomatal conductance ( g) and significantly increased root/shoot ratio (Rs), fine root/total root ratio (Ft) and δ 13 C under well-watered and water-stressed conditions. However, distinct interspecific differences were found in ABA-induced growth reduction, gas exchange decrease and δ 13 C increase. P. kangdingensis was more responsive to applied ABA than P. cathayana, resulting in larger decreases in Ht, Tb, La, E and g, and larger increases in Rs and ABA. In addition, P. kangdingensis also exhibited higher Ft and δ 13 C than P. cathayana under all experimental treatments. Our results provide strong evidence for adaptive differentiation between two contrasting poplar species in the eastern Himalaya.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.