【作者】 张迷离；

【导师】 韩烈保；

【作者基本信息】 北京林业大学 ， 草业科学， 2013， 硕士

【摘要】 口本结缕草(Zoysiajaponica)作为一种暖季型草坪草,在很多地区都会受到寒冷胁迫的制约,而其在寒冷胁迫下的机制并未完全被理解。本研究以两个品种的日本结缕草(普通(Chinese Common)和兰引三号(Lanyin-3))为材料,测定其低温胁迫下(21d)的主要抗寒性生理指标的变化。与此同时,深入测定寒冷胁迫初期(3d)的激素：ABA和H2O2及相关抗氧化酶的变化。最后以蒸馏水喷施为CK,研究了外施不同浓度的ABA和H202对普通日本结缕草的影响。本研究为日本结缕草抗寒性生理提供一定理论依据,为抗性育种及提高管理策略提供一定的指导作用。其研究结果表明：1、普通日本结缕草比兰引三号更抗寒,其半致死温度分别为-12.5℃和-9℃；2、在低温胁迫下,两个品种的结缕草的碳代谢产物(可溶性糖和淀粉)持续增长,氮代谢产物(脯氨酸和可溶性蛋白)持续增长,抗氧化酶活性(SOD、POD、 CAT)总体呈现先下降后上升的趋势。3、两个品种之间,抗寒性更强的普通日本结缕草能累积更多的糖代谢产物,脯氨酸和保持较高的SOD酶活性。4、在寒冷胁迫的初期(3d), ABA含量稳定,H202迅速升高；MDA持续上升,SOD、CAT活性下降,POD活性上升。5、外施高浓度的ABA和H2O2能降低日本结缕草的抗寒性；而低浓度和中等浓度的ABA和H202能提高日本结缕草抗寒性。其提高日本结缕草抗寒性的激素及浓度依次为：ABA100mmol/L> ABA50mmol/L> H2O2100mmol/L> H2O250mmol/L> H2O215mmol/L> ABA150mmol/L综上所述：在低温胁迫下,抗寒性强的结缕草能累积更多的碳水化合物产物,脯氨酸,以及保持更高的SOD酶活性。在寒性胁迫下的初期，信号分子H2O2可能位于ABA上游,作为主导信号分子。外源激素ABA和H2O2对日本结缕草的抗寒性都有影响,其中低浓度的ABA和H2O2能起促进作用,而高浓度的ABA和H2O2能引起更大的寒冷伤害。更多还原

【Abstract】 Zoysiagrass, a warm-season turfgrass species, experiences freezing damage in many regions, the mechanisms of its cold acclimation and freezing tolerance have not been well understood. This study was designed to investigate changes in metabolites (carbohydrate, proline, proteins), and antioxidant enzyme activity during cold acclimation(21d). Meanwhile, this study investigates the signal molecule (ABA and H2O2) and related MDA and antioxidant enzyme activity changes in the first period of cold acclimation (3d). Finally,3groups of different concentration of exogenous ABA and H2O2were sprayed on the I eaf of Zoysi a japonica cultivar Chi nese Common to study thei r effects on cold tolerance as water as CK. Two zoysiagrass cultivars (Chinese Common (cold tolerant) and Lanyin-3(relatively cold sensitive) were choose as materials. The objective of this study is to provide theoretic physiology reference of Zoysiagrass in cold acclimation, to provide certain guidance of resistant cultivars breeding and management improvement. The result showed that:1、The LT50of Chi nese Common and Lanyin-3are-12.5℃癈and-9℃respectively.2、The I eaf soluble sugar, starch, proline, and soluble protein content increased in response to cold acclimation. The leaf superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity tended to decline from0to7d and then increased from7to14d during cold acclimation.3、Common accumulated more metabolites (soluble sugars, starch, proline) and had higher SOD activity relative to Lanyin during cold acclimation.4、As to the first period of cold acclimation, the leaf hydrogen peroxide (H2O2) and and related MDA and antioxidant enzyme activity increased rapidly in response to cold acclimation while leaf ABA remain steady.5、High concentration of ABA and H2O2could decline the winter survival of Zoysiajaponica while low and middle level of concentration of ABA and H2O2could help to improve it. The effects of improving Chinese Common from the best to the worse is as following:ABA100mmol/L> ABA50mmol/L> H2O2100mmol/L> H2O250mmol/L> H2O215mmol/L> ABA150mmol/L In conclusion, the results suggest that the zoysiagrass cultivar with higher levels of carbohydrate, praline content, and SOD activity during cold acclimation period may have a greater winter survival than those with lower levels of carbohydrate and prolineand SOD activity. Moreover, H2O2may serve as signal for inducing antioxidant responses. Both of exogenousABA and H2O2have effects on the cold tolerance of zoysiagrass： low concentration of ABA and H2O2can help to improve the cold tolerance of zoysiagrasswhile high concentration ABA and H2O2help to deteriorate cold tolerance.更多还原