摘要
为了揭示干旱胁迫下钾对甘薯幼苗的抗旱机制,选取长势一致的甘薯幼苗放入1/4 Hoagland营养液培养,待第五片叶完全展开时,对幼苗进行高钾处理和干旱胁迫处理,研究高钾水平下干旱胁迫对甘薯幼苗光合特性及根系活力的影响。结果表明,未干旱胁迫条件下,高钾处理能够显著提高根系活力,但对甘薯幼苗光合特性影响甚微。干旱胁迫条件下,正常供钾和高钾处理的甘薯幼苗叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、表观量子效率(AQY)和光饱和点最大同化速率(Amax)等显著下降,呼吸速率(Rd)、光补偿点(LCP)和根系活力等显著上升,但干旱胁迫条件下高钾处理的Pn、Gs、AQY和Amax高于正常供钾处理,Tr,Rd和LCP等低于正常供钾处理。干旱胁迫下高钾处理的甘薯幼苗根系活力显著高于正常供钾处理,根系能够吸收更多的养分,减轻干旱胁迫对植株伤害。
The objective of this study was to evaluate the effects of potassium concentrations on the drought tolerance of root and leaves of sweet potato （ Ipomoea batatas Lam） . The seedlings and roots were exposed to different concentrations of potassium. The results showed that under drought stress, the net photosynthetic rate（ Pn ） , stomatal conductance（ Gs ） , transpiration rate（ Tr ） , apparent quantum efficiency（ AQY） and maximum assimilation rate（ Amax ） of sweet potato exposed to either high-or low-concentration potassium decreased significantly, while dark respiration rate（Rd）, light compensation point（ LCP） and root activity increased dramatically. The treatment of high potassium concentration can improve photosyn-thetic capacity of sweet potato under drought stress by raising Pn , Gs , AQY ,Amax and reducing Tr , Rd and LCP. Sweet po-tato exposed to high-concentration potassium held higer root vigor than that exposed to normal potassium supply, leading to more nutrient absorption and less damage by drought stress.
出处
《江苏农业学报》
CSCD
北大核心
2014年第5期992-996,共5页
Jiangsu Journal of Agricultural Sciences
基金
现代甘薯产业技术体系建设项目(CARS-11-B-13)
关键词
甘薯
干旱胁迫
钾
光合特性
根系活力
sweet potato
drought stress
potassium
photosynthetic characteristic
root activity
