【作者】 王宇；

【导师】 王晶英；

【作者基本信息】 东北林业大学 ， 植物营养学， 2010， 硕士

【摘要】 水曲柳是我国东北林区重要珍贵硬阔叶树种。低温危害对水曲柳造林的成活率、保存率都有重要影响。因此,掌握水曲柳寒害规律,揭示其在低温胁迫下受害和抗寒性改变的机制,并在此基础上提出有效的防治技术措施,对培育和保护水曲柳人工林具有重要意义。本文以盆栽水曲柳幼苗为材料,比较了人工低温或秋季自然降温条件下5种不同的外源物质对于水曲柳幼苗叶片防御系统的影响,测定了相对电导率、可溶性蛋白和可溶性糖含量、SOD和POD活性、光合速率等生理指标,研究了外源物质在水曲柳低温逆境中的生理效应,旨在获得一个提高水曲柳抗寒性的抗寒剂配方。研究结果如下：芸苔素浓度为1.0μmol·L-1和2.0μmol·L-1均能有效缓解电解质外渗量发生改变,增加可溶性蛋白质和增强保护酶活性,但2.0μmol·L-1处理不利于叶片低温下可溶性糖的积累。低浓度的0.7μmol·L-1的处理对于各生理指标基本无显著性影响。自然降温下,1.0μmol·L-1处理维持电导率不上升效果好于其它两种浓度处理。综合比较,1.0μmol·L-1浓度效果较好。复硝酚钠处理在常温下可提高水曲柳幼苗叶片胞内可溶物含量,对于人工低温胁迫下质膜透性的稳定及保护酶系没有明显效果,自然降温过程中对于电导率也无影响,对于水曲柳幼苗不表现出抗寒效果。脱落酸处理浓度为10mg·L-1时抗寒效果最好,能有效缓解电解质外渗量发生改变,增强保护酶活性和提高渗透调节物质含量。30mg·L-1和60mg·L-1脱落酸在人工低温下的电导率、可溶性蛋白含量和POD酶活性方面表现出一定程度的副作用。自然降温时,10mg·L-1脱落酸处理对于维持膜透性的稳定效果也比较好。综合比较,10mg·L-1浓度效果较好。亚精胺处理浓度为1mmol·L-1抗寒效果较好,可缓解0℃幼苗叶片电导率下降,提高渗透调节物质含量,增强SOD活性。5mmol·L-1浓度处理在可溶性蛋白和可溶性糖方面不如1mmol·L-1效果显著。而低浓度的0.5mmol·L-1处理对于生理指标的变化无明显影响。综合比较,1mmol·L-1浓度效果较好。浓度为50mg·L-1的赤霉素处理对于水曲柳抗寒性有帮助,可一定程度延缓0℃低温胁迫下的叶片电导率下降,提高渗透调节物质,一定程度增强保护酶SOD和POD活性。100mg·L-1、150mg·L-1处理表现出一定的抑制作用,效果不理想。综合比较,50mg·L-1浓度效果较好。在以上实验结果的基础上,配制了5种抗寒剂组合,在秋季自然降温过程中,通过光合指标和膜透性变化,确定了提高水曲柳抗寒性的抗寒剂配方,即10mg·L-1脱落酸,0μmol·L-1芸苔素,1mmol·L-1亚精胺,50mg·L-1赤霉素。更多还原

【Abstract】 The Fraxinus mandshurica was an important precious hard hardwood species of China Northeast forest. The low damage had a significant impact on survival rate and preservation rate of Ash afforestation. Thus, it was important that mastering the chilling injury of Fraxinus mandshurica and revealing the mechanism of their victimization and change on the cold temperature stress, and on this basis proposing effective measures for prevention and control technologies to nurture and protect the plantation of Fraxinus mandshurica. The Fraxinus mandshurica seedling was used to study the effects of five different exogenous substances on the defense system of seedling leaveseffects under the artificial low temperature or fall natural temperature reduction. The relative conductivity, soluble protein and soluble sugar content, SOD and POD activity, photosynthetic rate and other physiological indicators were measured. In this paper, the effects of exogenous substances on physiological characteristics of Fraxinus mandshurica seedling in responses to low temperature were studied to obtain an dose formulation that could increase cold resistance of Fraxinus mandshurica. The results were as follows:1.0μmol·L-1 and 2.0μmol·L-1 concentration of brassinolide could effectively alleviate the change of electrolyte leakage amount, increase the content of soluble protein and the activity of protective enzymes, but 2.0μmol·L-1 concentration processing was not conducive to the soluble sugar accumulation of leaf at low temperatures. The low concentrations of 0.7μmol·L-1 processing had no significant effect for all the physiological indexes. Under natural cooling, the 1.0μmol·L-1 processing to maintain the conductivity was better than the other two concentrations. Comprehensive comparison, the 1.0μmol·L-1 concentration of brassinolide was better.Sodium nitrophenolate could increase the intracellular soluble content of seedling leaves at room temperature, but had no significant effect on the stability of membrane permeability and the protective enzymes under artificial low temperature stress. Sodium nitrophenolate had no effect on the conductivity under the natural cooling process and did not show a cold tolerance effect for seedling.10mg·L-1 concentration of ABA was best, which could effectively alleviate the change of electrolyte leakage amount, enhance the protective enzymes and the content of osmotic adjustment matter. 30mg·L-1 and 60mg·L-1 ABA demonstrated a degree of side effects on the conductivity, soluble protein content and POD activity under artificial low temperature. Under natural cooling,10 mg·L-1 ABA in maintaining the stability of membrane permeability was better. Comprehensive comparison, the 10mg·L-1 concentration of ABA was better.1mmol·L-1 concentration of spermidine was better on cold intimidate, which could ease the decline of leaves conductivity at 0℃and enhance osmotic adjustment matter content and SOD activity.5mmol·L-1 concentrations was not more remarkable than 1mmol·L-1 in terms of soluble protein and soluble sugar. Low concentrations of 0.5mmol·L-1 was not significant for the physiological indices. Comprehensive comparison, lmmol·L-1 concentration was better.50mg·L-1 concentration of GA treatment was helpful to the cold resistance of Fraxinus mandshurica, a certain degree to delay the decreace of leaf conductance, increase osmotic adjustment matter content, to some extent enhance the activity of protective enzymes SOD and POD. 100mg·L-1, 150mg·L-1 treatment showed some inhibition and result was not satisfactory. Comprehensive comparison, 50mg·L-1 concentration was better.The five kinds of cold dose combination were preparated on the base of above results. In the autumn natural cooling process, the formulation that could improve the cold resistance of Fraxinus mandshurica was determined, that 10mg·L-1ABA,1.0μmol·L-1 brassinolide, 1mmol·L-1 spermidine, 50mg·L-1 GA.更多还原