等渗胁迫下聚乙二醇和氯化钠对喜旱莲子草生长的影响

喜旱莲子草（Alternanthera philoxeroides）为世界性恶性杂草,是中国国家环保总局公布的9种危害最大的外来入侵植物之一。采用不同渗透势的PEG（聚乙二醇）-6000和NaCl营养液模拟水分胁迫和盐胁迫处理喜旱莲子草,测定9d中其根数、根长、茎长、芽数、叶数的变化,旨在探讨喜旱莲子草对不同强度水分胁迫和盐胁迫的生理响应。结果显示,渗透势越低,根数、根长、茎长、芽数、叶数的增长越少,喜旱莲子草受PEG引起的低渗透势的影响比由NaCl引起的低渗透势的影响大,喜旱莲子草较强的耐旱和耐盐能力,是其快速适应多种生境的原因之一。

Effects of PEG and NaCl on the Growth of Alternanthera philoxeroides under Iso-osmotic Stress

Alligator weed,Alternanthera philoxeroides,is a kind of worldwide malignant weed and one of the listed 9 invasive plants in Chinese state biodiversity report.Different osmotic potentials of PEG-6000 and NaCl nutrient solution were used to simulate water and salt stress to determinate A.philoxeroides root,shoot and leaf number as well as the length of root and stem in 9 d.The objective of this study was to test main indexes of morphological changes of A.philoxeroides under different strength of water and salt stress.The results showed that A.philoxeroides has stronger salt endurance and drought hardiness,and the lower osmotic stress,the slower growth in root number,root length,stem length,shoot number and leaf number.They indicated that the effects of osmotic stress from PEG were greater than those from NaCl on growth of A.philoxeroides.These features are one of the reasons that A.philoxeroides can quickly adapt to many habitats.