【作者】 陈碧华；

【导师】 罗庆熙；

【作者基本信息】 西南农业大学 ， 蔬菜学， 2004， 硕士

【摘要】 高温是蔬菜生产中最常见的逆境因子，严重影响蔬菜的产量和品质，是造成夏秋之交蔬菜淡季的根本原因。因此，蔬菜耐热性研究备受关注，但在甘蓝上的耐热性研究较少有报道。而甘蓝由于适应性及抗逆性强，容易栽培，是我国各地普遍栽培的一种重要蔬菜作物，在蔬菜的周年供应中占有重要地位，秋甘蓝的育苗正值夏季高温多雨季节，造成育成的甘蓝幼苗质量差，抗逆性弱，严重影响后期产量和品质。可见，采取一定的生产措施来提高甘蓝幼苗的耐热性在生产上有一定的实际意义。 本试验以耐热性不同的三个甘蓝品种（夏光、西园四号、京丰一号）为材料，两种温度处理（不同温度预处理、热激处理）方式，分别采用二次回归正交旋转组合设计（包括温度、时间两个因子）进行温度处理。以苗期热害指数分析为依据实现对甘蓝幼苗耐热性的定量分析，并分别测定了三个甘蓝品种在9种处理组合下的与耐热性相关的生理生化指标：活力指数、电解质渗漏量、脯氨酸含量、可溶性蛋白质的含量、MDA含量、SOD活性、POD活性、CAT活性，从而较系统地从种子活力、细胞膜的热稳定性、膜脂过氧化、膜保护酶系统以及蛋白质代谢等角度研究了甘蓝种子经过温度处理后所发生的一系列生理生化变化，进一步探讨了影响甘蓝幼苗耐热性的机理。并通过温度处理试验，探讨了使甘蓝幼苗耐热性提高的最优温度时间处理组合，为生产上提供一定的处理水平参数。 1、试验结果表明：甘蓝种子经过温度处理后，与耐热性呈正相关的指标如活力指数、脯氨酸含量、可溶性蛋白质含量、束缚水含量、SOD活性、POD活性、CAT活性等指标均随着热害指数的降低而提高；而与耐热性呈负相关的指标如电解质渗漏量、MDA含量等指标均随着热害指数的降低而降低。回归分析结果显示，F^**＞F_（0.05）=3.33，回归可靠，说明温度、时间二因素与甘蓝耐热性相关的生理生化指标之间存在极显著的回归关系。 2、温度、时间二因子对甘蓝幼苗耐热性的影响主次是温度＞时间，其中温度因子对热害指数都有极显著影响，而处理时间则对热害指数是显著影响，并且二者之间存在交互作用。 3、试验结果显示，相同的温度处理下三个品种之间的耐热性差异较大，其耐热性具体表现为夏光＞西园四号＞京丰一号，其中三个品种经过温度处理后的热害指数表现为：夏光＜西园四号＜京丰一号。两种温度处理的结果比较起来，热激处理的效果优于不同温度预处理的效果。其中夏光高出31.04％，西园四号高出13.18％，京丰一号高出50.27％。 4、温度是影响蔬菜耐热性的一个重要外部条件，但是温度处理时间也是影响耐热性的一个重要因素，通过本试验得出温度处理的最优组合：不同温度预处理最优组合分别是夏光21.2℃27.8h，西园四号21.2℃27.5h，京丰一号20.2℃20.1h，在此条件下热害指数分别为：西南农业大学硕士学位论文夏光5.09%，西园四号6.22%，京丰一号n.08%;热激处理的最优组合分别是夏光42.3℃2.3h，西园四号42.2℃2.3h，京丰一号42.2℃2.3h，在此条件下热害指数分别为夏光3.51%，西园四号5.4既，京丰一号5.51%o 5、本试验结果还显示，三个品种热激处理的最优处理组合没有区别，几乎是同一水平，但是耐热性表现为:夏光)西园四号>京丰一号，其中热害指数分别为夏光3.51%，西园四号5.40%，京丰一号5.51%o 综合上述，在最优温度处理条件下，与耐热性呈正相关的指标如活力指数、脯氨酸含量、可溶性蛋白质含量、束缚水含量、SOD活性、Pon活性、’CAT活性等均有所增加，以及与耐热性呈负相关的指标如热害指数、电解质渗漏量、MDA活性等有所降低，为甘蓝幼苗耐热性的提高打下了良好的生理生化基础。 可见，温度处理能有效降低幼苗期热害指数，提高甘蓝幼苗的耐热性，为甘蓝幼苗度过炎热夏季奠下坚实基础，使幼苗群体生长势良好，为后期高产高效提供了可靠的保证;并且这种处理方法简单，成本低，效益高，为下一步推广应用奠定了坚实的基础。总之，本试验结果能为甘蓝的夏季育苗工作和耐热栽培提供一定的理论依据和技术参数。更多还原

【Abstract】 High temperature is the most unfavorable factor in vegetable production. It seriously influences the quality and output of vegetable and is a basic reason for the shortage of vegetables in summer and autumn seasons. Therefore, studies on heat-durability of vegetables are paid to great importance. Up to now there are few reports on the heat-durability of cabbage. Because cabbage is of strong adaptability and anti-adversity, they are easily cultivated, so it has become an important vegetable in China and occupy an important status in anniversary supply of vegetables. The seedling of autumn cabbage is bred in summer when it is hot and rainy, which results in the bad quantity and less anti-adversity of cabbage seedlings, and seriously influences the subsequent yield and quality. Therefore, adopting certain cultivation method to enhance heat-durability of seedlings is of great importance in cabbage production.The material used in the experiment are three cabbages species(Xiaguang, Xiyuan NO. 4, Jingfeng NO.1), They are applied with two temperature treatment methods(different temperature pretreatment and heat-activation treatment) respectively, using the response surface design (including temperature and time two factors). According to the test of seedling heat-damage index, quantitative analyses have been achieve for the heat-durability of cabbage seedlings, and it has been measured for the heat-related physiological and biochemical indexes of three cabbage species in nine combined treatments. Consequently, the physiological and biochemical changes in cabbage seeds after temperature treating are systematically studied. Furthermore, the mechanisms that affect heat-durability of cabbage seedlings are discussed. By the experiment, the best temperature and time treat combinations are acquired for the improvement of cabbage seedling heat-durability, which may provide to cabbage production.1. The result indicates: after treating with temperature, all indexes have positive relation with heat-durability of cabbage seeds such as vitality, proline content, dissolubility protein content, binding water content, SOD activity, POD activity, CAT activity etc, all of them increase as the heat-damage index reducing; those have negative relation with heat-durability such as electrolyte pervasion, MDA content etc. all go down as heat-damage index. The statistics show that,temperature and treat time have remarkable regressive relations with physiological and biochemical index that related with heat-durability of cabbage.2. The influence on heat-durability of cabbage seedling is temperature>time, and temperature has remarkable influence on heat-damage index.3. The result shows that, heat-durability among three species has big difference under the same temperature treatment , the heat-durability is Xiaguang>Xiyuan No. 4>Jingfeng No. l.and after temperature treating , the heat-damage index of these three species is Xiaguang<Xiyuan No. 4< Jingfeng No.1. Comparing the result of two temperature treatments, the effect of heat-activating is better than that of temperature pretreatment. Among three species, Xiaguang exceed 31.04%, Xiyuan No.4 13.8%, Jingfeng No. 1 50.27%, respectively.4. Temperature is an important exterior condition that affect the heat-durability of vegetable, the treat time is also an important factor to affect the heat-durability of vegetable. The best combination under different temperature pretreatment is Xiaguang, 21.2℃ and 27.8h; Xiyuan No.4, 21.2℃ and 27. 5h; Jingfeng No. 1, 20. 2℃ and 20.1h respectively. Under these treatments the heat-damage index would be Xiaguang 5. 09%, Xiyuan No. 4 6. 22%, Jingfeng No.1 11.08%, respectively. The best combinations by heat-activation treatment are Xiaguang, 42.3℃ and 2. 3h, Xiyuan No. 4 ,42.2℃ and 2.3h, Jingfeng No. 1, 42.2℃ and 2. 3h, The heat-damage index under the treats would be Xiaguang 3.51%, Xiyuan No. 45.40%, Jingfeng No. 15. 51%.5.The study also indicates that the best combinations after heat-activate treating to three species have no difference,更多还原