摘要: |
全球气候变化背景下,研究树木不同种源对干旱-复水的生理生态响应,将有助于理解种源地气候条件对树木抗旱性的影响,可为未来森林的经营与管理提供理论参考。该研究以广东与福建种源木荷为对象,通过盆栽控水方式模拟干旱及复水条件,研究木荷两个种源的水力及碳生理特征、脯氨酸(Pro)及超氧化物歧化酶(SOD)对干旱-复水的响应。结果表明:(1)对照情况下,广东种源的茎木质部水势(Ψxylem)、叶片相对含水量(RWC)、光合速率(Asat)与气孔导度(Gs)均低于福建种源;(2)两个种源木荷的水力特征、Pro与SOD对干旱-复水的响应呈一致趋势,其中Ψxylem、RWC与Pro均能较快恢复至对照水平,而茎木质部栓塞程度与SOD未恢复至对照水平;(3)福建种源木荷叶片的Asat对干旱的敏感性较广东种源的高,且复水后恢复至对照水平需要更长时间;(4)复水后福建种源木荷NSC的恢复速率高于广东种源。综上所述,福建与广东种源木荷均不能通过短期复水(30天)来修复被栓塞的木质部。尽管广东种源木荷的光合速率能够更快的恢复至对照水平,但其光合速率低于福建种源的木荷,并且其NSC的恢复能力较福建种源的低。因此在未来干旱加剧背景下,广东种源木荷的生长及存活可能受到更大威胁。 |
关键词: 干旱-复水,光合特征,水力特征,木荷,种内差异 |
DOI: |
分类号: |
基金项目:国家自然科学(31760111)。 |
|
Eco-physiological responses of Schima superba seedlings from two provenances to drought and re-watering |
王德福, Zhao Nan1,2,2,2,2,3, Qiu Wanbin1,3, Sang Dongxin1,3, Huang Guomin1,3, Liu Wenfei1,3, Shen Fangfang1,3, Duan Honglang4
|
1.Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems &2.amp;3.Watershed Ecohydrology, Nanchang Institute of Technology;4.Institute for Forest Resources and Environment of Guizhou, Guizhou University
|
Abstract: |
In the context of global climate change, the research on eco-physiological responses to drought and re-watering among provenances of trees species will help to understand the effect of climate change, further providing theoretical references for cultivation and management of forests in the future. In this study, Schima superba from two provenances in southern China were selected. Potted seedlings were subjected to simulated drought and re-watering conditions. Eco-physiological traits (photosynthesis traits, hydraulic traits, non-structural carbohydrates-NSC, proline concentrations-Pro and superoxide dismutase-SOD activity) of seedlings were examined. Our results indicate that: (1) Under well-watered condition, stem xylem water potential (Ψxylem), leaf relative water content (RWC), photosynthetic rate (Asat) and stomatal conductance (Gs) were lower in seedlings from Guangdong provenance compared with Fujian provenance. (2) Responses of hydraulic traits, Pro and SOD to drought and re-watering were consistent between the two provenances. Ψxylem, RWC and Pro could recovery to control values rapidly, while percent of stem xylem embolism and SOD could not recovery to control values in the end; (3) Asat was more sensitive to drought from Fujian provenance than Guangdong provenance, and it took more time to recovery to control in Fujian provenance. (4) The recovery rate of NSC from Fujian provenance was faster than Guangdong provenance. Collectively, seedlings from both provenances could not repair their embolized xylem in the short-term rewatering period (30 days). Although photosynthesis rate in Guangdong provenance could recover to control faster than from Fujian provenance, it was lower than that from Fujian provenance. Furthermore, the recovery rate of NSC was slower in Guangdong provenance than Fujian provenance, indicating that growth and survivals of seedlings from Guangdong provenance may experience greater risk in future characterized with increasing drought stress. |
Key words: Drought-rewatering, photosynthetic traits, hydraulic traits, Schima superba, intra-specific differences |