不同钾素供应和光强对油菜叶片光合能力的影响  

Effects of different potassium supply and light intensity on photosynthetic capacity of oilseed rape leaves

作　　者：何紫瑶 陈其睿 胡文诗 谷贺贺 宋毅 叶晓磊 张洋洋[1] 陆志峰[1] 任涛[1] 鲁剑巍[1] HE Zi-yao;CHEN Qi-rui;HU Wen-shi;GU He-he;SONG Yi;YE Xiao-lei;ZHANG Yang-yang;LU Zhi-feng;REN Tao;LU Jian-wei(College of Resources and Environment,Huazhong Agricultural University/Microelement Research Center,Huazhong Agriculutral University,Wuhan 430070,China)

机构地区：[1]华中农业大学资源与环境学院/华中农业大学微量元素研究中心,湖北武汉430070

出　　处：《中国油料作物学报》2024年第4期843-854,共12页Chinese Journal of Oil Crop Sciences

基　　金：国家自然科学基金(32072680);湖北省现代农业产业技术体系(HBHZD-ZB-2020-005);中央高校基本科研业务费专项基金(2662021ZH001)。

摘　　要：为明确钾素供应和光强对油菜叶片生长和光合特性的影响,本研究采用钾素供应和光强两因素的试验设计,其中钾素供应设计3个水平,分别为严重缺钾(0.03 mmol·L^(-1)KCl)、轻度缺钾(0.09 mmol·L^(-1)KCl)和充足钾供应(2.00 mmol·L^(-1)KCl),光强设置2个水平,分别为低光强(LL,~200μmol·m^(-2)·s^(-1))和高光强(HL,~400μmol·m^(-2)·s^(-1)),在水培条件下研究了不同钾素供应和光强处理油菜叶片的生长、气体交换参数、叶绿素荧光特征以及叶肉细胞超微结构特征,以期为多变环境条件下钾肥的合理施用提供理论依据。结果表明,钾素供应和光强显著影响油菜叶片的生长。相同的钾素供应下,高光强处理油菜叶片厚度和比叶重较低光强分别增加了19.6%~24.3%和57.1%~73.6%,而在严重缺钾胁迫时,净光合速率较低光强条件降低了63.8%。严重缺钾胁迫叶片在高光强条件下受到光抑制,实际光化学效率、最大羧化速率和最大电子传递速率等光合关键参数明显降低,叶绿体发育不良,同时缺钾导致叶肉细胞间空隙比例减小,叶肉导度降低,进而使得叶片光合能力显著下降。综上所述,钾素供应和光强共同调节叶片形态结构,影响光合能力,高光强下钾素供应不足会严重影响油菜的生长,合理施用钾肥有利于提高油菜对光强变化的适应性,保持光合能力的稳定。To clarify the effects of potassium(K)supply and light intensity on leaf growth and photosynthetic characteristics of oilseed rape,a two-factor experimental design with K supply and light intensity was performed in this study,in which three levels of K supply were designed:severe K deficiency(0.03 mmol·L^(-1)KCl),mild K deficiency(0.09 mmol·L^(-1)KCl)and sufficient K supply(2.00 mmol·L^(-1)KCl),and two levels of light intensity were set:low light intensity(LL,~200μmol·m^(-2)·s^(-1))and high light intensity(HL,~400μmol·m^(-2)·s^(-1)).The growth,gas exchange parameters,chlorophyll fluorescence characteristics and mesophyll cell ultrastructure characteristics of oilseed rape leaves under different K supply and light intensity under hydroponic conditions,in order to provide a theoretical basis for the rational application of K fertilizer under changing environmental conditions.The results showed that K supply and light intensity significantly affected the growth of oilseed rape leaves.Under the same K supply,the leaf thickness and leaf dry mass per area of oilseed rape increased by 19.6%~24.3%and 57.1%~73.6%,respectively,under high light intensity treatment compared with low light intensity,while the net photosynthetic rate decreased by 63.8%under severe potassium deficiency stress compared with low light intensity conditions.Severely K-deficient stressed leaves were photoinhibited under high light intensity conditions,and the actual photochemical efficiency,maximum carboxylation rate,maximum electron transfer rate and other key photosynthetic parameters were significantly reduced,and chloroplasts were poorly developed.While K deficiency led to a reduction in the proportion of intercellular spaces between mesophyll cells,and a decrease in mesophyll conductance,which in turn led to a significant decline in photosynthetic capacity of leaves.To sum up,K supply and light intensity jointly regulate leaf morphology and structure,affecting photosynthetic capacity.Insufficient K supply under high light intensity wil

关 键 词：油菜 钾 光照强度 光合作用 叶绿体超微结构 叶绿素荧光 

分 类 号：S565.4[农业科学—作物学]