摘要
石斛属植物因其附生生境的特殊性,水分获取困难。为了弄清石斛属植物对干旱胁迫的适应能力,选用3年生金钗石斛和铁皮石斛苗,通过盆栽控水进行干旱胁迫和复水处理,研究了干旱历时20、40、60 d和复水历时10、15、20 d时两种石斛光合作用的变化情况。结果表明:随着干旱时间的延长,金钗石斛叶片净光合速率(P_(n))、气孔导度(G_(s))和蒸腾速率(T_(r))均呈下降趋势,胞间CO_(2)浓度(C_(i))呈先降低再升高的趋势,复水后,除C_(i)外,P_(n)、G_(s)和T_(r)均未恢复到充分供水时的水平;随干旱时间的延长,铁皮石斛叶片P_(n)和G_(s)呈先升高后降低的趋势,C_(i)和T_(r)呈先降低再升高的趋势,复水后,P_(n)、C_(i)、G_(s)和T_(r)均恢复到了充分供水时以上的水平。同时,金钗石斛和铁皮石斛在干旱早期(40 d前),P_(n)与C_(i)和G_(s)的变化趋势基本一致,P_(n)的下降主要由气孔限制引起,而干旱后期(40 d后),P_(n)的下降主要由非气孔限制引发。并且,金钗石斛和铁皮石斛叶片水分利用效率(WUE)随干旱时间的延长均整体呈升高趋势,复水20 d时,其日平均WUE分别是充分供水时的4.99和1.91倍。综上,金钗石斛和铁皮石斛均具有较强的抗旱能力,铁皮石斛表现出强于金钗石斛的复水恢复能力。同时,在WUE上,两种植物干旱后复水均表现出一定程度的补偿性增长。并且,通过对干旱胁迫和复水过程光合生理特征的综合分析,初步认为两种石斛属植物均为干旱避免型植物。
Dendrobium plants are difficult to obtain water because of the particularity of epiphytic habitat.In order to clarify the adaptability of Dendrobium plants to drought stress,3-year-old Dendrobium nobile and Dendrobium officinale seedlings were selected for drought stress and rehydration treatment through potted water control to study the changes of photosynthesis in two Dendrobium species after 20,40,60 days of drought and after 10,15,20 days of rewatering.The results showed that with the prolongation of drought time,the net photosynthetic rate(P_(n)),stomatal conductance(G_(s))and transpiration rate(T_(r))of Dendrobium nobile showed a downward trend,and the intercellular CO_(2)concentration(C_(i))first decreased and then increased.After rehydration,except for C_(i),all of P_(n),G_(s)and T_(r)did not return to the level of sufficient water supply;with the prolongation of drought time,P_(n)and G_(s)of Dendrobium officinale showed a trend of first increase and then decrease,C_(i)and T_(r)showed a trend of first decreasing and then increasing.After rehydration,P_(n),C_(i),G_(s),and T_(r)all recovered to the levels above the sufficient water supply.At the same time,in the early stage of drought(before 40 days),the change trends of P_(n),C_(i)and G_(s)of Dendrobium nobile and Dendrobium officinale were basically the same,and the decrease of P_(n)was mainly caused by stomatal limitation,while in the later period of drought(after 40 days),the decrease of P_(n)was mainly initiated by non-stomatal limitation.Moreover,the water use efficiency(WUE)of Dendrobium nobile and Dendrobium officinale increased with the prolongation of drought time,and the daily average WUE was respectively 4.99 and 1.91 times higher than that of adequate water supply,after 20 days of rehydration.In conclusion,both Dendrobium nobile and Dendrobium officinale have strong drought resistance,and Dendrobium officinale shows stronger recovery ability than Dendrobium nobile.At the same time,in WUE,the rehydration of the two plants after drought showed a
作者
吕朝燕
高智席
邓富梅
韩畅
魏英
LÜChao-yan;GAO Zhi-xi;DENG Fu-mei;HAN Chang;WEI Ying(School of Biological and Agricultural Technology,Zunyi Normal College,Zunyi 563006,Guizhou Province,China;Institute of Food Green Processing and Nutrition Control Engineering,Zunyi Normal College,Zunyi 563006,Guizhou Province,China)
出处
《节水灌溉》
北大核心
2023年第2期111-120,127,共11页
Water Saving Irrigation
基金
贵州省科技计划项目(黔科合基础-ZK[2022]一般574)
学术新苗培养及创新探索项目培育项目(黔科合平台人才[2017年]5727-17号)
贵州省教育厅特色领域项目(黔教合KY字[2020]060)
贵州省高校第一批服务农村产业化项目(遵师合农村产业字201906)
贵州省省级教学内容和课程体系改革项目(2019140)
遵义市科技计划项目(遵市科合HZ字[2021]21号)。
关键词
金钗石斛
光合作用
干旱胁迫
复水
铁皮石斛
植物逆境
Dendrobium nobile
photosynthesis
drought stress
rewatering
Dendrobium officinale
plant adversity
