摘要
于雾凉季研究了西双版纳热带雨林 4种植物幼苗对光抑制及光破坏的防御。发现不同光强下生长的玉蕊和滇南红厚壳日间光抑制均较团花树和滇南插柚紫重 ,在中光强下还发生了长期光抑制。中光强下生长的团花树和滇南插柚紫叶绿素含量降低 ,光合能力升高 ,同时增加热耗散量 ,维持光能平衡 ,避免了光破坏的发生。中光强下玉蕊和滇南红厚壳减少光能吸收、提高热耗散的同时 ,发生了光系统II光化学量子产量长期下调。中光强下生长的 4种植物叶片的类胡罗卜素的绝对含量并不高 ,但单位叶绿素的类胡罗卜素含量显著升高 ,相对保护作用增强。先锋树种团花树类胡罗卜素含量低于另 3种植物 ,这与其较低的热耗散速率相一致 。
In the foggy and cool season in 2000 photoinhibition of photosynthesis and the strategies of photoprotection were explored for seedlings of four tropical rainforest tree species as given below. Both Anthocephalus chinensis (Lam.) Rich. ex Walp. and Linociera insignis C.B.Clarke are light demanding, while both Calophyllum polyanthum Wall. ex Choisy and Barringtonia macrostachya (Jack) Kurz, are shade tolerant. In C.polyanthum and B.macrostachya diurnal photoinhibition of photosynthesis, as judged by F v/F m , was severe than that in A.chinensis and L.insignis , regardless of growth light regimes, and chronic photoinhibition occurred in intermediate light regimes (50% of sunshine) (Fig.2 and Table 1). In intermediate light regimes A.chinensis and L.insignis could maintain light energy balance and avoid photodamage by decreasing light capture through decreasing chlorophyll content (Table 3), and by increasing both photosynthetic capacity (Table 2) and thermal dissipation (Fig.3). While chronic downregulation of photochemical quantum yield of photosystem Ⅱ occurred in C.polyanthum and B.macrostachya , although they could decrease light energy capture (Table 3) and increase thermal dissipation (Fig.3) too. Compared with those in low light regimes, the carotenoid content expressed as unit leaf area was not higher for the four species seedlings grown under intermediate light regimes, but was higher significantly when expressed as unit chlorophyll (Table 3). This mean that relative photoprotection increased in intermediate light regimes. The carotenoid content of A.chinensis , a pioneer tree species, was lower than those of other three tree species (Table 3), which was consistent with its lower thermal dissipation rate (Fig.3). Its high photosynthetic capacity was very important in avoidance of photodamage.
出处
《植物生理与分子生物学学报》
CAS
CSCD
2002年第2期153-160,共8页
Journal Of Plant Physiology and Molecular Biology
基金
中国科学院"百人计划"资助项目部分研究内容
关键词
生长光强
热带雨林
树苗
光合机构
光抑制
光合能力
热耗散
色素含量
photoinhibition of photosynthesis, photosynthetic capacity, thermal dissipation, chloroplast pigment content, tropical rainforest tree species
