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以冬小麦(烟台-2070)为实验材料,苗期对冬小麦进行不同浓度钠盐(NaCl、Na2CO3、Na2SO4)处理,在随后进行的干旱胁迫和复水过程中进行叶片抗逆生理指标变化对比分析,以期探究盐处理在提高小麦抗旱性中的作用和生理调节机理,为未来干旱区农业实施盐水灌溉提供理论依据。实验采用盆栽法,将冬小麦种子盆栽,待长到第7天进行不同浓度钠盐(70mM,135mM,200mM,270mM)预处理8d,然后进行干旱胁迫12d和复水5d。分别在盐处理的第4天,第8天,干旱胁迫的第4天,第8天,第12天,以及复水第5天,从不同盐处理中采集冬小麦叶片,分析叶片相对含水量、丙二醛(MDA)、脯氨酸含量及抗氧化酶活力[超氧化物岐化酶(SOD)、过氧化氢(CAT)、过氧化物酶(POD)]的动态变化,同时测定土壤含水量。结果表明,在干旱胁迫过程中,未经盐处理的对照组和低浓度(70mM)NaCl、Na2CO3、Na2SO4溶液处理的土壤,土壤含水量急剧下降,同时冬小麦叶片相对含水量也相应的急剧下降;而用较高盐浓度处理的土壤和冬小麦叶片含水量降低较慢。在干旱胁迫过程中,对照组冬小麦在短时间(6d)内干旱叶片便出现萎蔫,并伴随着丙二醛、脯氨酸含量、SOD等抗氧化酶活力急剧增加并一直高于盐处理的冬小麦。相反高浓度盐处理的冬小麦在干旱处理12d时叶片直立生长良好,叶片MDA、抗氧化酶活力均增加,但增加幅度均低于对照。脯氨酸含量随干旱胁迫增加,但随盐处理浓度增加而上升幅度减小。在复水处理5d后,叶片含水量均增加,MDA和脯氨酸含量下降,但抗氧化酶活力仍增高。荒漠环境土壤中盐离子一方面可提高土壤和植物的保水率,提高水分利用率,另一方面激活体内的抗氧化酶系统使植物较早获得抗逆能力,这可能是荒漠植物多抗逆性形成的部分生理生化原因。
Taking winter wheat (Yantai-2070) as experimental material, winter wheat was treated with different concentrations of sodium salt (NaCl, Na2CO3, Na2SO4) at seedling stage, comparative analysis was conducted on the changes of physiological index of leaves during drought stress and rewatering, In order to explore the role of salt treatment in improving wheat drought resistance and physiological regulation mechanism for the future implementation of salt water irrigation in arid areas provide a theoretical basis. Pot experiments were carried out to plant winter wheat seeds in pots. After seven days, different concentrations of sodium salt (70mM, 135mM, 200mM, 270mM) were pretreated for 8 days, then subjected to drought stress for 12 days and rehydration for 5 days. Winter wheat leaves were collected from different salt treatments on the 4th day, the 8th day, the 4th day, the 8th day, the 12th day and the 5th day after the rehydration. The relative water content, (MDA), proline content and antioxidant enzyme activity [superoxide dismutase (SOD), hydrogen peroxide (CAT), peroxidase (POD) Water volume. The results showed that in the process of drought stress, the soil water content decreased sharply and the relative water content of winter wheat decreased sharply in the control group and the soil treated with low concentration (70mM) NaCl, Na2CO3, Na2SO4 solution without salt treatment. However, the water content of soil and winter wheat treated with higher salt concentration decreased more slowly. During drought stress, the control group of winter wheat appeared wilting in a short time (6 days), accompanied by the rapid increase of malondialdehyde, proline content and the activities of antioxidant enzymes such as SOD and higher than the salt-treated winter wheat . On the contrary, the high-salt-treated winter wheat had good upright growth 12 d after drought treatment, and the activities of MDA and antioxidant enzyme in leaves increased, but the increasing range was lower than the control. Proline content increased with drought stress, but decreased with the increase of salt concentration. After rehydration treatment for 5 days, leaf water content increased, MDA and proline content decreased, but antioxidant enzyme activity still increased. On the one hand, the salt ions in the desert environment can increase the water retention rate of soil and plants and increase the water use efficiency. On the other hand, activate the antioxidant enzyme system in the body to make the plant get earlier resilience, which may be the result of multi-resistance of desert plants The formation of part of the physiological and biochemical reasons.