不同浓度海藻糖处理对西瓜幼苗低温抗性的影响

Effects of different concentrations of trehalose on the cold tolerance ofwatermelon seedlings

为探讨不同浓度海藻糖处理对西瓜幼苗低温抗性的影响,以农科大五号西瓜品种为试验材料,以清水25℃/18℃(昼/夜)为常温对照(CK),用0、5、10、15、20 mmol·L^(-1)海藻糖对西瓜幼苗进行叶面喷施预处理,10℃/7°C(昼/夜)低温胁迫7 d后测定分析最大光化学效率、相对电导率、丙二醛含量、抗氧化酶活性、根系活力、干鲜质量。结果表明,与0 mmol·L^(-1)海藻糖相比,15 mmol·L^(-1)海藻糖处理可以显著提高西瓜幼苗抗氧化酶活性、根系活力、干鲜质量,降低叶片相对电导率和丙二醛含量,增强幼苗的抗冷性,其中超氧化物歧化酶(SOD)活性升高了36.29%,过氧化物酶(POD)活性升高了43.65%,根系活力提高了127.21%,地上部鲜质量增加了89.20%,地上部干质量增加了80.35%,地下部鲜质量增加了166.95%,地下部干质量增加了107.61%,叶片相对电导率降低了23.01%,丙二醛含量降低了25.32%;而5、10、20 mmol·L^(-1)海藻糖处理大多数生理指标之间没有显著差异。综上所述,叶面喷施海藻糖可以增强西瓜幼苗的低温抗性,其中15 mmol·L^(-1)海藻糖处理效果最好。

In order to explore the effects of trehalose treatment at different concentrations on low temperature resistance of watermelon seedlings,the watermelon cultivars named Nongkeda No.5 was used as the test material,and 0,5,10,15,20 mmol·L^(-1) trehalose was applied to watermelon seedlings in foliar spray treatment with water 25℃/18°C(day/night)as normal temperature control(CK).Maximum photochemical efficiency,relative electrical conductivity,malondialde-hyde content,antioxidant enzyme activity,root viability,dry fresh weight were measured and analyzed after 7 days of 10℃/7°C(day/night)cold stress.The results showed that compared with 0 mmol·L^(-1) trehalose,the autioxidant enzyme activities,the root viability,dry fresh weight were significantly increased and relative conductivity of leaves,malondialde-hyde content were significantly reduced by the treatment of trehalose with 15mmol·L^(-1) concentration,and the cold resis-tance of watermelon seedlings was enhanced.Among them,superoxide dismutase(SOD)activity increased by 36.29%,peroxidase(POD)activity increased by 43.65%,root viability increased by 127.21%,the fresh weight of shoot increased by 89.20%,the dry weight of shoot increased by 80.35%,the fresh weight of root increased by 166.95%,the dry weight of root increased by 107.61%,relative conductivity of leaves decreased by 23.01%and malondialdehyde content decreased by 25.32%.While there was no significant difference in most physiological indicators of trehalose treatment at 5,10,20 mmol·L^(-1) concentration.In conclusion,spraying trehalose on leaves can enhance the low temperature resistance of watermelon seedlings,and 15 mmol·L^(-1) trehalose treatment showed the best effect.