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以小蓬竹为试材,以自然光为对照,研究了轻度遮阴(LS,74.32%自然光)、中度遮阴(MS,44.83%自然光)、重度遮阴(SS,18.57%自然光)3种遮阴处理对小蓬竹的光合作用和光响应特征的影响,以探讨濒危植物小蓬竹对光照的适应性。结果表明:轻度遮阴下小蓬竹叶片光合速率(Pn)、最大净光合速率(Pnmax)、表观量子效率(AQE)以及光能利用效率(LUE)相对于对照(CK)有所提高,而光饱和点(LSP)、光补偿点(LCP)以及暗呼吸速率有所下降;中度及重度遮阴下小蓬竹叶片Pn等气体交换性指标,AQE、Pnmax、LSP、LCP以及暗呼吸速率(Rd)等光响应参数均随遮阴加重而逐渐下降,但LUE却极显著升高。说明小蓬竹对轻度遮阴环境有良好的适应性,适度遮阴更有利于其生长发育。遮阴加重的情况下,小蓬竹直接地提高LUE、降低LCP和LSP,维持一定光合作用水平并减少能量消耗,使其在光照不足条件下迅速实现碳的净积累,从而加强对弱光逆境的抵御能力。由此推断,小蓬竹对中度及重度遮阴环境具有较强的适应性。
The experiment was conducted with light shading (LS, 74.32% natural light), moderate shading (MS, 44.83% natural light), severe shading (SS, 18.57% natural light) 3 Shading treatments on photosynthesis and photosynthetic characteristics of Phyllostachys heterocycla cv. Phyllostachys pubescens were studied in order to investigate the adaptability of the endangered Phyllostachys praecox to light. The results showed that the photosynthetic rate (Pn), Pnmax, AQE and LUE of Phoebe bryophyte increased slightly under light shading compared with control (CK) (LSP), light compensation point (LCP) and dark respiration rate decreased; PQ and other indicators of gas exchange under moderate and severe shading, AQE, Pnmax, LSP, LCP and dark The photoresponse parameters such as respiration rate (Rd) gradually decreased with increasing shading, but LUE increased significantly. Description Phyllostachys light shade of the environment has a good adaptability, shade is more conducive to their growth and development. Under the shading conditions, Phyllostachys pubescens increased LUE directly, decreased LCP and LSP, maintained a certain level of photosynthesis and reduced energy consumption, enabling it to rapidly achieve a net carbon accumulation in low light conditions, Resilience. It can be inferred that Phyllostachys pubescens has a strong adaptability to moderate and severe shady environments.