孕穗期低温条件下ABA对水稻结实率及叶片生理特性的影响

Effect of ABA on Seed-setting Rate and Physiological Characteristics of Rice Leaves Under Low Temperature Stress at Booting Stage

为了明确ABA对孕穗期低温下水稻结实率及叶片生理特性的调控效应,本试验在盆栽条件下,以2个水稻(Oryza sativa L.)品种‘龙粳11’(冷敏型)和‘龙稻5’(耐冷型)为材料,于孕穗期在人工气候室进行低温(15℃,持续1,2,3,4,5天)处理,并喷施不同浓度的脱落酸(ABA),研究低温条件下ABA对不同水稻结实率的调控效应,同时探讨了ABA和低温对水稻叶片膜透性、抗氧化酶等生理特性的影响。结果表明:低温条件下,‘龙稻5’的结实率变化不大,‘龙粳11’的结实率显著降低,20 mg/L的ABA能够有效缓解低温伤害,相对提高低温胁迫下水稻的结实率。叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性表现出先升高后下降的变化趋势,‘龙稻5’的抗氧化酶活性、可溶性糖和可溶性蛋白含量高于‘龙粳11’,但丙二醛(MDA)含量和相对电导率低于‘龙粳11’。ABA可提高冷敏品种的抗氧化酶活性、可溶性糖和可溶性蛋白的含量,同时可降低MDA含量和相对电导率。这说明ABA可以通过调控水稻抗氧化酶、可溶性糖等生理指标的活性及含量,进而提高冷敏水稻品种的耐冷性。

The aim is to clarify the regulating effects of ABA under low temperature stress on seed-setting rate and physiological characteristics of rice leaves at booting stage. This study was conducted with two ricecultivars‘Longjing11＇（cold sensitive） and‘Longdao5＇（cold tolerant） which were planted in pots. At bootingstage,the low temperature treatments（15℃,lasting 1,2,3,4,5 d） were carried out in climatic laboratory. Thedifferent concentrations of abscisic acid（ABA） were sprayed. The regulating effects of ABA on the seed-settingrate of different rice cultivars were studied. The effects of ABA and low temperature on the membranepermeability of leaf and antioxidant enzyme were also discussed. The results showed that the seed-setting rate of‘Longdao5＇had little change in low temperature condition,and the seed-setting rate of‘Longjing11＇decreased significantly. Spraying of 20 mg/L ABA could effectively alleviate the cold damage,and the seed-setting rate was improved relatively under low temperature. The activities of SOD,POD and CAT in leaves firstshowed an increasing trend then a decreasing trend. The activities of antioxidase,contents of soluble sugar andsoluble protein of‘Longdao5＇were higher than those of‘Longjing11＇,but the content of malondialdehyde（MDA） and relative conductivity were lower than that of‘Longjing11＇. It indicated that ABA could increasethe cold tolerance of cold sensitive rice cultivar through regulating some physiological characteristics such asthe activities of antioxidant enzyme,the content of soluble sugar in leaf.