冷季粤西野生香根草及扁穗牛鞭草对模拟光的生理响应  

Physiological Response of Wild Vetiveria zizanioides(L.) Nash and Hemarthria compressa(L.f.) R. Br. to the Simulated Light Source in West Guangdong during the Cool Season

作　　者：林保花[1] 王立[2] 刘金祥[3] 杨允菲[4] 

机构地区：[1]广东药学院药科学院,广州510006 [2]哈尔滨工业大学市政环境工程学院,哈尔滨150090 [3]湛江师范学院生命科学与化学学院,湛江524048 [4]东北师范大学草地科学研究所,植被生态科学教育部重点实验室,长春130024

出　　处：《草地学报》2009年第2期213-217,共5页Acta Agrestia Sinica

基　　金：广东省“千百十”优秀人才基金(Q02113);湛江市科技攻关项目(2002101);湛江师院自然科学基金(Z108);国家自然科学基金项目(30470272,30770397)资助

摘　　要：香根草(Vetiveria zizanioides(L.)Nash)和扁穗牛鞭草(Hemarthria compressa(L.f.)R.Br.)是广东吴川地区野生香根草群落的建群种和主要伴生种,为从生理生态的角度探讨2种植物的共存及对冷季的适应问题,利用LI-6400光合仪的人工控制系统,于2004年12月下旬,对群落优势种野生香根草和扁穗牛鞭草的光合生理特性进行测定,比较分析两种植物的光合特性和水分利用特性。结果表明:在冷季,野生香根草和扁穗牛鞭草的光补偿点分别为13.37μmol.m-2.s-1和12.77μmol.m-2.s-1,光饱和点为1100μmol.m-2.s-1,均发生光抑制现象,扁穗牛鞭草的光利用能力高于香根草,比香根草耐阴;香根草的气孔调节机制优于扁穗牛鞭草,在一定程度上对水分利用起到了较好的调节作用,提高了水分利用率。2种植物对季节性干旱气候适应对策分别表现为,扁穗牛鞭草以保持较高光合速率来提高水分利用效率,而香根草则通过调节气孔来限制水分的无效散失。Vetiveria zizanioides （L.） Nash is the dominant species and Hemarthria compressa （L. f. ） R. Br. the main companion species in the natural V. zizanioides community in Wuchuan region, Guangdong province. Mechanisms of coexistence and the adaptive strategy during cool season were compared between V. zizanioides and H. compressa by their photosynthetic and physiological characters measured by LI- 6400 portable photosynthesis system in later December. Results show that the light compensation point （Lcp） and light saturation point （Lsp） of V. zizanioides were 13.47 μmol · m -2 · s-1 and 1100 μmol · m -2 · s-1,and those of H. compressa were 12.77μmol · m -2 · s-1 and 1100 μmol · m -2 · s-1, respec- tively, in cool season. Photoinhibition occurred in both species in intense light. H. compressa had higher light use efficiency than V. zizanioides which accorded with the growth habitat of the two species. The stomatal regulation mechanism of V. zizanioides was superior to that of H. compressa in correspondence to its water use efficiency. Adaptive strategies were different between two species in response to seasonal drought; H. compressa improved the water use efficiency through high net photosynthetic rate and V. zizanioides limited water dissipation through stomatal regulation.

关 键 词：香根草 扁穗牛鞭草 光合特性 水分利用特性 适应对策 冷季 

分 类 号：Q945.11[生物学—植物学] S540.1[农业科学—作物学]