| 摘要: |
| 【目的】探讨外源细胞分裂素6-BA预处理对干旱胁迫条件下蒙原欧李生理响应特性的影响，为蒙原欧李抗旱机制研究提供参考。【方法】以蒙原欧李盆栽苗为材料，通过不同质量浓度的6-BA预处理后，采用断水方法对苗木进行干旱胁迫处理，分析6-BA预处理对蒙原欧李叶片水分状况（叶片相对含水量(RWC)、水分饱和亏缺(WSD)）、光合色素（叶绿素a、叶绿素b、类胡萝卜素(Car)）、光合性能（净光合速率(Pn)和光合性能指数(PIABS)）、渗透调节能力（脯氨酸(Pro)和可溶性蛋白(SP)）、抗氧化系统（超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)）、细胞伤害程度（丙二醛(MDA)）及综合抗旱性的影响。【结果】断水5 d时，200 mg/L 6-BA预处理对提高蒙原欧李植株综合抗旱性的效果最好，可使WSD降低32.2%，Pn和PIABS分别提高37.9%和49.5%，Pro增加64.0%，POD和CAT活性分别提高26.6%和54.3%；断水10 d时，100 mg/L 6-BA预处理对提高植株综合抗旱性的效果最好，可使WSD降低62.6%，Car/Chl a+b提高50.0%，MDA含量减少34.7%，POD和CAT活性分别增强116.8%和32.2%；断水15 d时，100 mg/L 6-BA预处理对提高植株综合抗旱性的效果最好，可使WSD降低30.4%，Chl a、Chl b、Chl a+b、Car、Pn和PIABS分别提高38.7%，64.6%，42.8%，24.4%，84.0%和22.4%，MDA含量减少29.5%，SP和Pro分别增加43.6%和47.1%,POD活性增强460.3%；断水20 d时，150 mg/L 6-BA预处理对提高植株综合抗旱性的效果最好，其可使Car/Ch a+b提高5.7%，MDA减少35.7%，POD、CAT活性分别提高119.0%和27.6%。【结论】6-BA预处理对干旱胁迫条件下蒙原欧李生理特性的调节作用受干旱胁迫程度和6-BA质量浓度的共同影响。叶面喷施适宜质量浓度的6-BA，能够在一定程度上缓解干旱胁迫对蒙原欧李植株造成的伤害，提高其综合抗旱性。 |
| 关键词: 欧李 细胞分裂素 干旱胁迫 生理特性 |
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| 基金项目:内蒙古自治区自然科学基金项目（2020MS03083,2019MS03072,2018MS03052）;内蒙古农业大学高层次人才引进科研启动项目（NDYB2016-16） |
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| Effects of 6-BA pretreatment on physiological characteristics of Mengyuan Cerasus humilis under drought stress |
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ZHANG Xiaoyan,LI Lianguo,GUO Jinli,et al
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| Abstract: |
| 【Objective】This paper explored effects of exogenous cytokinin 6-BA pretreatment on physiological characteristics of Mengyuan Cerasus humilis under drought stress.【Method】Mengyuan Cerasus humilis was planted in pot and seedlings were treated with drought stress by water cut-off method after 6 -BA pretreatments at four suitable concentrations.Relative water content (RWC),water saturation deficit (WSD),chlorophyll a,chlorophyll b,carotenoid,net photosynthetic rate (Pn) and photosynthetic index (PIABS),proline (Pro) and soluble protein (SP) contents,superoxide dismutase SOD,peroxidase POD and catalase CAT) activities as well as malondialdehyde (MDA) content were measured.Then the effects of 6-BA pretreatment on water status,photosynthetic pigment,photosynthetic activity,osmotic regulators,antioxidant system,cell injury and drought resistance were studied.【Result】The pretreatment of 200 mg/L 6-BA was the best in improving comprehensive drought resistance of plants when water was cut off for 5 days,causing 32.2% reduction in WSD,37.9% and 49.5% increases in Pn and PIABS,64.0% increase in Pro,and 26.6% and 54.3% increase in activities of POD and CAT,respectively.When water was cut off for 10 days,100 mg/L 6-BA pretreatment was the best with 62.6% reduction in WSD,50.0% increase in Car/Chl a+b,34.7% decrease in MDA,and 116.8% and 32.2% increases in activities of POD and CAT,respectively.When water was cut off for 15 days,100 mg/L 6-BA pretreatment was the best with 30.4% reduction in WSD,38.7%,64.6%,42.8%,24.4%,84.0% and 22.4% increases in Chl a,Chl b,Chl a+b,Car,Pn and PIABS,29.5% decrease in MDA,43.6% and 47.1% increases in SP and Pro,and 460.3% increases in activities of POD,respectively.When water was cut off for 20 days,150 mg/L 6-BA pretreatment was the best,causing 5.7% increase in Car/Chl a+b,35.7% decrease in MDA,and 119.0% and 27.6% increases in activities of POD and CAT,respectively.【Conclusion】 he effects of 6-BA pretreatment on physiological characteristics of Mengyuan Cerasus humilis under drought stress were influenced by drought stress level and 6-BA concentration.Spraying 6-BA at suitable concentration on leaves can alleviate the damage caused drought stress and improve its comprehensive drought resistance. |
| Key words: Cerasus humilis exogenous cytokinin drought stress physiological characteristics |
