【作者】 杨春祥；

【导师】 李宪利； 高东升；

【作者基本信息】 山东农业大学 ， 果树学， 2005， 硕士

【摘要】 本研究于2003-2005 年在山东农业大学果树试验站进行,以油桃几个品种曙光(Prunus persica var. nectaria Maxim.cv.Shuguang)、早红宝石(Prunus persica var. nectarine Maxim.cv.Zaohongbaoshi)、中油四号(Prunuspersica var.nectarina Maxim.cv.Zhongyousihao)为试材,对几个油桃品种花期和幼果期的抗寒性状进行了观察和测定,初步探明了低温胁迫下油桃花器官生理生化变化规律及适应低温胁迫的相应生理生化机制,同时对CaCl2、SA 和6-BA 三种低温保护剂的抗寒机制进行了初步研究。主要研究结果如下:1.低温胁迫下电解质渗透率变化规律:随着低温加剧,油桃花果相对电导率增加,造成细胞膜透性增大。电解质渗透率表现出慢-快-慢有规律的变化,变化曲线呈“S”型。2.油桃不同品种和花器官对低温迫的适应能力不同。通过配合Logistic 方程测定了它们的低温半致死温度。花蕾期曙光、早红宝石、中油四号三个品种的半致死温度分别为-6.02℃、-5.51℃和-5.04℃;盛花期三个品种的半致死温度分别为-4.68℃、-4.17℃和-3.98℃;然而在幼果期三个品种半致死温度趋于一致。对于同一品种而言,蕾期抗寒性大于盛花期,盛花期抗寒性大于幼果期。对于同一朵花而言,通过褐变率的观察发现,不同部分的抗寒性由强到弱为花瓣,雄蕊和雌蕊。3.低温胁迫下植物体内物质发生相应的有规律的变化:在低温处理过程中,随着低温胁迫的加剧,可溶性糖、游离氨基酸、脯氨酸含量有持续增加的趋势,但前期的增长速率大于后期;蛋白质含量前期呈现升高趋势,但是达到一定低温后,开始下降;植物体内保护酶活性变化也呈现出先升高后降低的趋势,即在胁迫温度较低时,酶的活性升高,达到一定低温后酶活性下降;植物体内有毒物质MDA 含量随着低温的加剧表现出持续增加的趋势。4.喷施适宜浓度的CaCl2、水杨酸、6-BA 溶液等保护剂能够降低低温胁迫下花朵的电解质渗透率和MDA 含量,减轻了膜脂过氧化作用,从而提高了油桃花期的抗寒能力,三种保护剂均能提高低温胁迫下花朵的可溶性蛋白、脯氨酸含量。三种保护剂对低温胁迫下保护酶活性的作用不同,更多还原

【Abstract】 The research had been carried out in the garden of college of horticulturalscience and engineering, Shandong Agricultural University from 2003 to 2005 .The experimental materials were 6-year-old nectarine trees, includingshuguang(Prunus persica var. nectarina Maxim. cv. Shuguang),zaohongbaoshi(Prunus persica var. nectarina Maxim.cv. Zaohongbaoshi) andzhongyousihao (Prunus persica var. nectarine Maxim. cv. Zhongyousihao).The characters of cold-resistance of nectarine trees were observed anddetermined in flower stage and young fruit stage. The variational physiologicaland biochemical mechanism and corresponding response for chilling stresswere proved up primarily in nectarine flower organs. In the same time, thecold-resistance mechanism of cryoprotectants such as CaCl2, salicylic acid and6-BA was researched elementarily. The main results were indicated as follows:1. The changes of the leakage of electrolyte in nectarine flowers and youngfruits under chilling stress were increased with the strengthened chilling stresswhich increased the permeancing of cell membrane. The changes of theleakage of electrolyte showed slowly-fast-slowly and the changing curvesshowed ‘S’model.2. The adapting capability under chilling stress was different with thedifferent nectarine varieties and flower organs. Their lethal temperatures ofpercent 50 under chilling stress were determined through cooperating logisticequation. The lethal temperatures of percent 50 under chilling stress in budflower of three varieties including shuguang, zaohongbaoshi andzhongyousihao were -6.02℃,-5.51℃and -5.04℃respectively. The lethaltemperatures of percent 50 under chilling stress of three varieties in full flowerwere -4.68℃,-4.17℃and -3.98℃severally. But the lethal temperatures ofpercent 50 under chilling stress of three varieties in young fruits tended to besimilarly. To the same variety, the cold-resistance in bud flower was strongerthan that in full flower, the cold-resistance in full flower was stronger than thatin young fruit. To the same full flower, through observing the rating ofbrowning it showed that the cold-resistance of flower organ was petal, stamenand pistil from strong to infirmness. 3. The substance in plants under chilling stress showed regularily change.With the strengthening of chilling stress during the process of decliningtemperature, the contents of soluble sugar, dissociating amino acid and pralinewere increased continuously, but the increasing rate in the prophase was fasterthan the post-phase; the content of protein showed increase in the prophase,but it began to decrease when reaching a certain low temperature; Theactivities of protecting enzymes in plant also showed increasing in the first,then decreasing in the end, namely, the activities of protecting enzymesincreased under mild chilling stress, and the activities of protecting enzymesbegan to decrease when reaching a certain low temperature; the contents ofMDA which was poisonous to plant increased with the strengthening ofchilling stress. 4. The appropriate concentration cryoprotectant solution such as CaCl2,salicylic acid and 6-BA could decrease the leakage of solution and the contentsof MDA, alleviate the membrane lipid peroxidation, accordingly enhance theability of cold-resistance in full flower stage under chilling stress. The threekinds of cryoprotectant all enhanced the contents of soluble protein andproline in full flower under chilling stress. The three kinds of cryoprotectantshad different effects on protective enzymes under chilling stress. Sprayingappropriate solution of CaCl2 and 6-BA could enhance the activities of SOD,POD, CAT and APX under chilling stress in full flower stage, while sprayingappropriate solution of salicylic acid could increase the activities of SOD andPOD and decrease the activities of CAT and APX . The result of mensuratingrelated protective enzymes in young fruit under chilling stress showed thatspraying appropriate concentration solution of CaCl2 and 6-BA could enhancethe activities of SOD, POD and CAT; Spraying appropriate concentrationsolution of salicylic acid could enhance the activities of SOD and POD, but更多还原