四种苹果砧木幼苗对NaCl胁迫的生理响应、根系生长及耐盐性评价

Effect of NaCl stress on growth and physiological characteristics of four kinds of apple stock

【目的】探讨盐胁迫下四种苹果砧木幼苗的根系构型和生理响应,评价其耐盐性能.【方法】以6叶龄八棱海棠(BL)、垂丝海棠(CS)、花叶海棠(HY)、新疆野苹果(XJ)幼苗为试材,采用Hoagland营养液水培的方式,在营养液中加2.0mg/g NaCl模拟盐胁迫.【结果】低盐胁迫下,四种苹果砧木幼苗根系的根长、根尖数、根表面积和根系活力缓慢下降;叶绿素含量呈现先升后降的趋势.随胁迫时间的延长,丙二醛(MDA)含量胁迫前期缓慢上升,胁迫后期急剧下降.过氧化物歧化酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性随胁迫时间延长均呈先升后降的趋势,有明显峰值.【结论】根据隶属函数总和的大小对苹果砧木幼苗的耐盐性能进行排序,四种砧木耐盐性由强到弱的顺序为:XJ>CS>HY>BL.

[Objective] To study the response of root system growth and physiological characteristics, and understand the tolerance of four kinds of apple rootstocks under low salt stress. [Method] Four root- stocks （BL,CS,HY and XJ） in the 6-leaf age were employed as experiment materials. Hydroponic culture in Hoagland nutrient liquid were carried out with added 2.0mg/g NaCl in nutrient solution to simulate salt stress. [Result]The root length, root number, root surface area and root activity of the seedlings decreased slowly under the stress. Chlorophyll content increased first, subsequently decreased. With the extension of stress time, contents of MDA increased gradually during the early stage of stress,and decreased sharply at the later stage of stress. The activity of SOD, POD and CAT increased firstly, then decreased. [Conclusion] The order of the tolerance of four kinds of apple rootstocks under low salt stress is as XJ〉CS〉HY〉BL, according to the fuzzy subordination method.