摘要：以冷敏感型西瓜品种“橙兰”为试验材料，采用清水、20000倍碧护、3000倍禾稼春、20000倍碧护加3000倍禾稼春的复配剂各10ML进行灌根预处理，研究两种植物生长调节剂在2℃低温胁迫下对西瓜幼苗叶绿素相对含量、植株干重、快速叶绿素荧光、抗氧化酶活性及MDA、可溶性蛋白含量的影响。结果显示：（1）复配剂、禾稼春、碧护三种处理能提高西瓜幼苗叶片叶绿素相对含量、植株干重。（2）常温和低温胁迫下，三种处理叶片的光合性能均优于对照。（3）低温胁迫下，三种处理提高了西瓜幼苗叶片SOD、POD、APX三种抗氧化酶活性及可溶性蛋白含量，降低了MDA含量，但对西瓜幼苗叶片CAT活性无影响。以上结果显示，禾稼春及其与碧护复配可以进一步提高植物耐寒性，其中至少部分原因与植物抗氧化酶活性上升有关。

关键词：禾稼春、碧护、西瓜幼苗、快速叶绿素荧光、低温胁迫

Effects of Two Chemicals on Leaf Photosynthesis and Antioxidant Enzyme Activities of Watermelon Seedlings under Cold Stress

Abstract：【Objective】To study the effect of this two agentias on chlorophyll relative content, dry weight, fast chlorophyll fluorescence, antioxidant enzyme activity, MDA and soluble protein content of watermelon seedlings at 2 ℃ low temperature stress, 【Method】the cold sensitive watermelon variety " Cheng Lan " was used as the experimental material, and each 10ml of clear water, 20000 times Vitacat , 30000 times "Cropspring" and the compound mixing with 20000 times Vitacat and 30000 times "Cropspring" was pretreated by root irrigation. 【Result】The results showed:(1)The compound, Cropspring and VitaCat could improve the Relative chlorophyll content and leaves' dry weight of watermelon seedling;(2)The photosynthetic property of the leaves with three different treatments were improved comparing with the control group, no matter at ordinary temperature or low temperature;(3)Under cold stress, three treatments improved the activities of SOD, POD and APX, and improved the soluble protein content, and reduced MDA content, and they had no effect on CAT in the watermelon's leaves. 【Conclusion】These results imply that application of Cropspring and its compound with VitaCat can improve the cold resistance of plants, at least in part due to the increase in antioxidant enzyme activity.

Key words: Crospring；Vitavat；Watermelon Seedling；Fast Chlorophyll Fluorescence；Cold Stress

目  录

摘要3

关键词3

Abstract3

Key words3

引言3

1材料与方法4

1.1材料 4

1.2试验处理 4

1.3生理指标测定4

1.4数据处理5

2结果与分析5

2.1两种药剂对西瓜幼苗叶片叶绿素相对含量的影响5

2.2两种药剂对西瓜幼苗干物质产量的影响5

2.3两种药剂对低温胁迫下西瓜幼苗叶片快速叶绿素荧光诱导动力学曲线的影响5

2.4两种药剂对低温胁迫下西瓜幼苗叶片快速叶绿素荧光诱导动力学参数的影响6

2.5两种药剂对低温胁迫下西瓜幼苗叶片820nm光吸收曲线的影响7

2.6两种药剂对低温胁迫下西瓜幼苗抗氧化酶活性、MDA含量、可溶性蛋白含量的影响8

2.7两种药剂对西瓜幼苗低温胁迫后恢复情况的影响8

3讨论 9

4结论 10

致谢10

参考文献10

两种药剂对低温胁迫下西瓜幼苗光合特性及抗氧化酶活性的影响

引言：近年来，全球气候变化异常，中国冬春季节的气温屡创新低，植物在低温条件下会遭到不同程度的伤害，严重时甚至会导致植株死亡，大大降低农作物的产量和品质。西瓜（Citrullus lanatus）喜高温干燥，较不耐寒。目前西瓜品种多数耐冷性弱，栽培时受季节限制较大，且缺乏耐冷种质资源。因此，解决西瓜的耐冷性问题对西瓜冬春季节保护地栽培和提高西瓜的产量、品质具有十分重要的意义。