干热处理对甜瓜种子活力和细菌性果斑病抑制能力的影响

Effects of Dry-heat Treatment on Seed Vigor and Controlling Bacterial Fruit Blotch of Melon

以厚皮甜瓜品种‘哈密绿’种子为材料,在70℃、75℃和80℃温度下分别处理24h、48h和72h,研究不同干热处理对甜瓜种子活力萌发和生理生化指标变化及细菌性果斑病的防治效果。结果显示:(1)随着处理温度的升高和时间的延长,干热处理甜瓜种子发芽指标和成苗率显著下降,而70℃处理24h和48h对种子发芽指标(活力指数除外)和成苗率无显著影响。(2)与对照相比,干热处理种子胚芽中的SOD活性、可溶性糖和脯氨酸含量升高,在同一温度处理下,SOD活性和可溶性糖含量随着处理时间的延长基本呈增长趋势,脯氨酸含量则随着处理时间的延长呈下降趋势,POD和APX活性以及可溶性蛋白含量变化随着温度的升高和处理时间的延长呈下降趋势;与对照相比,胚芽中CAT活性在70℃处理下降低,而在75℃和80℃处理下升高,但其随着处理时间的延长呈下降趋势;胚芽中O-·2产生速率在70℃和75℃处理下与对照接近,而在80℃处理下随着处理时间的延长呈上升趋势,且均显著高于对照。(3)随着处理温度的升高和时间的延长,甜瓜接菌种子幼苗细菌性果斑病发病率较对照显著降低。研究表明,适宜干热处理温度和时间诱导甜瓜种子中抗氧化酶活性增强,渗透调节物质含量增加,超氧阴离子产生速率降低,种子活力和出苗率有效提高,‘哈密绿’种子有效、安全的干热处理组合为70℃、48h。

In this study,with melon variety ＇Hamil＇ as material,we studied the seed vigor indexes,physiological and biochemical changes,and controlling bacterial fruit blotch of different dry-heat treatments （temperature： 70 ℃,75 ℃,80 ℃;time： 24 h,48 h,72 h）.The results as followed： （1） the seed germination indexes and seedling rate of melon significantly decreased with the increase treatment of temperature and time.However,the treatments of 70 ℃ for 24 h and 48 h had no significant effect on seed germination index （except vigor index） and seedling rate.（2） Compared with the control,SOD activity,soluble sugar and proline contents of melon germ increased.At the same temperature,SOD activity and soluble sugar content showed a increasing trend,while proline content decreased with the increase of time treatments;on the other hand,the POD,APX activities and soluble protein content decreased with the increase of temperature and time treatments.Compared with the control,CAT activity decreased of 70 ℃ treatment and increased of 75 ℃ and 80 ℃ treatments,but they were decreased with the increase of time treatments.Compared with the control,changes of O-·2 production rate of 70 ℃ and 75 ℃ treatments had no significant difference,but it increased with the increase of time treatment under 80 ℃ treatment.（3） Compared with the control,seed inoculated Acidovorax citrulli of melon seedlings significantly decreased with the increase of temperature and time treatments.Comprehensive analysis showed that the proper dry-heat treatments and times caused enhances in antioxidant enzyme activities and osmotic adjustment substance contents,decreases in O-·2 production rate,as well as increased seed germination indexes and seedling rate.Meanwhile,the results showed that 70 ℃ for 48 h was the effective and safe treatment for melon seeds.