花铃期不同钾效率基因型棉花对干旱和低钾胁迫的响应差异  

Differential Response of High and Low Potassium Use Efficiency Cotton Genotypes to Drought and Low Soil Potassium Stress at the Flowering and Boll Setting Stage

作　　者：汪霄[1,2] 陈防[1,3] 

机构地区：[1]中国科学院武汉植物园/水生植物与流域生态重点实验室,武汉430074 [2]中国科学院研究生院,北京100049 [3]国际植物营养研究所中国项目部,武汉430074

出　　处：《棉花学报》2015年第1期16-21,共6页Cotton Science

基　　金：国家自然科学基金"棉花钾高效基因型的高效生理机制与根际土壤矿物钾风化特性研究"(41171243);国际植物营养研究所科研基金(IPNI-HB-34)

摘　　要：以钾高效和钾低效基因型棉花(HEG和LEG)为试验材料,研究了最优水肥(W1K1),干旱胁迫(W2K1),低钾胁迫(W1K2),干旱、低钾胁迫(W2K2)对其光合作用及水分、钾素利用率的影响。结果表明:干旱显著降低花铃期2种基因型棉花叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr),导致蕾铃脱落,钾素利用率(KUE)降低,造成棉花减产。施钾促进叶片Pn及水分利用率(WUE)的提高,但基因型间存在差异,LEG叶片WUE与施钾量成正比,HEG相反。低钾胁迫下HEG的Pn、Tr下降,但Pn下降幅度小于Tr,WUE增大。较高的WUE有利于提高棉花Pn,降低蕾铃脱落率,促进钾素的高效吸收和运输。To investigate the effects of soil water and potassium（K）on genotypic variation in photosynthesis, water and K use ef- ficiencies, pot experiments were carried out with two cotton genotypes （a high K utilization efficiency cotton genotype and a low K utilization efficiency cotton genotype referred as HEG and LEG, respectively） and four treatments： optimum water and K （W1K1）, drought stress（W2K1）, low K stress（W1K2）, drought and low K stresses（W2IC2）. The results indicated that soil drought had significantly negative effect on cotton net photosynthetic rate （Pn）, stomatal conductance （Gs） and transpiration rate （Tr）, then leading to falling of buds or bolls and decreasing the K use efficiency and yield. Application of K fertilizer improved cottons＇ Pn and water use efficiencies （WUE）. There was a significant difference of WUE between genotypes. The WUE of LEG was notably and positively correlated with K applying, whereas HEG was on the contrary. Both Pn and Tr of HEG cotton de- creased under low soil K condition, while WUE increased because the change of Pn was smaller than Tr Higher WUE was con- ductive to higher absorption and transportation of K by increasing Pn and decreasing buds and boll falling ratio. Our findings will provide a new theoretical basis for further exploring of high K use efficiency mechanism.

关 键 词：水钾耦合 棉花 基因型 光合参数 水分利用效率 钾素利用效率 

分 类 号：S562[农业科学—作物学]