摘要
以濒危植物华山新麦草为材料进行盆栽试验,设置3个水分梯度,研究生长指标、气体交换、叶绿素荧光参数、光合色素含量、光响应特征及丙二醛(MDA)含量。结果表明:随干旱胁迫的加剧,株高、叶宽和光合色素含量降低,根长和丙二醛(MDA)含量增加;水分胁迫导致净光合速率(PN)、气孔导度(gs)、蒸腾速率(E)、最大荧光(Fm)、光合电子传递速率(ETR)和光化学猝灭系数(qP)降低,胞间CO2浓度(Ci)、瞬时水分利用效率(WUE)、初始荧光(Fo)和非光化学淬灭系数(NPQ)升高;光系统Ⅱ最大光化学效率(Fv/Fm)不变;干旱胁迫下光响应曲线拟合结果显示,干旱胁迫造成最大光合速率和光能利用效率下降。综上表明,干旱对光系统Ⅱ的伤害是制约华山新麦草光合作用的主要原因。
Abstract： Psathyrostachys huashanica Keng is a perennial herb belongs to Gramineae and only distributes in Huashan area of Qinling Mountain, Shaanxi Province, China. At present, the amount of the population is much less than the past and suffers the risk of extinction. Owing to distributing limitation and importance as breeding material for germplasm storage, it has been listed into the first class of rare and endangered species of the nation and imperatively protected wild species in relation to crops. Drought is the major environmental stress limiting growth and yield of plants worldwide. Mean global temperature and evaporation rate are expected to rise over the next few decades and as a consequence the crop demand for water will increase. It is well known that inhibition of photosynthesis is one of the primary physiological consequences of drought stress. For this reason, the study of photosynthetic characteristics with related to drought stress is worthwhile in exploration of the acclimation and conservation of this endangered species. In the present paper, the response of photosynthetic characteristics to drought stress in P. huashanica Keng was studied by measuring growth parameters, gas- exchange, photosynthetic pigment contents, modulated chlorophyll fluorescence and malonaldehyde （MDA） contents under 3 different drought stresses in a pot experiment. The result exhibited that, when increasing drought stress, plant height, the width of leaf and photosynthetic pigment contents decreased and root length and MDA contents enhanced. Drought stress induced the decrease of net photosynthesis （Pn）, stomatal conductance （gs）, ratio of transpiration （E）, the maximum fluorescence （F）, the electron transport rate （ETR） and photochemical quenching （qp） and an increase of ratio of intercellular CO2, intrinsic water use efficiency （ WUE）, the minimal fluorescence （ Fo ） and non-photochemical quenching（NPQ）. Meanwhile, the maximum quantum yield of photo-system II （PSII） （Fv/
出处
《生态学报》
CAS
CSCD
北大核心
2012年第13期4278-4284,共7页
Acta Ecologica Sinica
基金
国家自然科学基金(31070362)
关键词
华山新麦草
水分胁迫
光合作用
光合特性
Psathyrostachys huashanica Keng
drought stress
photosynthesis
photosynthetic characteristics
