外源ABA对干旱胁迫及复水下弥勒苣苔生长的影响

Effects of Exogenous ABA on Paraisometrum millense Growth Under Drought Stress and Rewatering

为促进弥勒苣苔(Paraisometrum mileense)在干旱区域的应用,本研究通过调查喷施ABA后弥勒苣苔在5种干旱胁迫处理下植株形态和部分生理指标的变化及各生理指标的相关性,分析外源ABA对干旱胁迫下弥勒苣苔生长的影响。结果表明:对干旱处理的弥勒苣苔喷施ABA后植株萎蔫程度有所缓解,仍存在部分绿叶,相对电导率、丙二醛(MDA)、脯氨酸(Pro)和可溶性糖(SS)含量均显著低于干旱处理(P<0.05)。复水后,植株叶片恢复舒展柔软鲜绿,相对电导率、MDA和Pro含量与对照无显著性差异;但SS含量有差异,喷施ABA复水后的植株SS含量恢复至对照处理水平,而未喷施ABA复水后的植株SS含量则显著高于对照和其他处理(P<0.05)。MDA与脯氨酸和相对电导率呈显著正相关,相对电导率与脯氨酸也表现为显著正相关,即弥勒苣苔相对电导率增加的同时还伴随着丙二醛和脯氨酸含量的大量增加。综上,弥勒苣苔具有很强的抗旱性,喷施ABA不仅能延长绿叶期、提高抗旱性,还能促进迅速返青、恢复观赏性。

In order to promote the application of Paraisometrum millense in arid areas,this study investigated the changes of plant morphology and some physiological indexes of P.mileense under five drought stress treatments after spraying ABA and the correlation of various physiological indexes.The effects of exogenous ABA on the growth of P.mileense under drought stress were analyzed.The results showed that the wilting degree of P.mileense treated with drought was alleviated after spraying ABA,and there were still some green leaves.The relative electrical conductivity,malondialdehyde(MDA),proline(Pro)and soluble sugar(SS)contents were significantly lower than those of drought treatment(P<0.05).After rewatering,the leaves of the plant returned to stretch,soft and bright green,and the relative conductivity,MDA and Pro contents were not significantly different from those of the control.However,the SS content was different.After spraying ABA and rewatering,the SS content of plants returned to the control treatment level.The SS content of plants without ABA spraying was significantly higher than that of the control and other treatments(P<0.05).MDA was significantly positively correlated with proline and relative conductivity,and the relative conductivity was also significantly positively correlated with proline.That is,the increase of relative conductivity of P.mileense was accompanied by a large increase in the content of malondialdehyde and proline.In conclusion,P.mileense has strong drought resistance.Spraying ABA can not only prolong the green leaf period and improve the drought resistance,but also promote the rapid return to green and restore the ornamental.