【作者】 赵海亮；

【导师】 高东升； 李宪利；

【作者基本信息】 山东农业大学 ， 果树学， 2007， 硕士

【摘要】 本实验于2005年~2007年在泰安群星果品示范园进行;以七年生曙光油桃(Prunus persica var. Nectarina.cv.Shuguang)为试材对不同温度梯度短时间冰冻低温处理对桃芽自然休眠解除的影响及生理生化机制进行了研究。主要结果如下:1、短时间冰冻处理对解除曙光油桃芽休眠有显著作用。当油桃植株进入休眠后,只要休眠达到一定程度,短时间冰冻处理可有效解除芽休眠;并且短时间冰冻处理对芽休眠的解除效果随处理时期的推迟、处理温度的降低及处理时间的延长而增强。-4℃和-7℃短时间冰冻处理对曙光油桃芽自然休眠解除的影响不大;-10℃以后短时间冰冻处理较为显著促进曙光油桃芽自然休眠的解除,但是随着短时间冰冻低温处理温度的降低、处理时期的推迟和处理时间的延长,出现部分桃芽因冰冻处理而死亡的现象,尽管如此,在存活芽中短时间冰冻处理对桃芽休眠解除的效果明显增强。2、11月30日短时间冰冻处理中,-4℃和-7℃处理桃芽的自由水/束缚水比值及相对电导度与对照差别不大;而-10℃以后处理的自由水/束缚水比值和相对电导度与对照相比明显升高。12月10日和20日短时间冰冻处理变化趋势与11月30日基本一致,只是前者对桃芽自然休眠解除的促进效应明显优于后者,相同处理芽的自由水/束缚水比值和相对电导度明显高于11月30日处理。不同短时间冰冻处理的萌芽级数和自由水/束缚水比值及相对电导度的相关分析表明,短时间冰冻处理可有效解除芽休眠,并显著促进了水分由束缚态向自由态的转变以及膜透性的增加。3、11月30日短时间冰冻处理中,-4℃和-7℃处理桃芽中淀粉含量和可溶性糖含量与对照相差不大;而-10℃以后各处理中,其芽内可溶性糖含量与对照相比升高,淀粉含量降低。12月10日和20日短时间冰冻处理中,-4℃和-7℃处理桃芽中可溶性糖含量和淀粉含量与对照相差无几;但-10℃以后各处理桃芽内可溶性糖含量不仅与对照相比升高,而且明显高于11月30日的相同处理,淀粉含量则显著低于对照和11月30日处理。不同短时间冰冻处理的可溶性糖含量及淀粉含量和萌芽级数的相关分析表明,短时间冰冻处理可有效解除芽自然休眠,促进淀粉向可溶性糖的快速转化。4、11月30日短时间冰冻处理中,-4℃和-7℃处理桃芽中O2-产生速率、H2O2含量和·OH产生速率及POD、CAT和SOD活性与对照相比差异不大;但-10℃以后各处理芽内O2-产生速率、H2O2含量和·OH产生速率及POD、CAT活性与对照相比明显升高,而SOD活性显著降低。12月10日和20日短时间冰冻处理变化趋势与11月30日基本一致;只是-10℃以后各处理芽内O2-产生速率、H2O2含量和·OH产生速率及POD、CAT活性显著高于对照和11月30日短时间冰冻处理,SOD活性则显著低于对照和11月30日冰冻处理。过氧化氢(H2O2)含量、超氧阴离子自由基(O2-·)和羟基自由基(·OH)产生速率的显著增加表明短时间冰冻处理可有效解除芽自然休眠,并且活性氧的迅速增加很可能是短时间冰冻处理解除芽自然休眠的部分原因。5、11月30日短时间冰冻处理中,-4℃、-7℃和-10℃处理,与对照相比,总酚含量、PAL活性与PPO活性变化不大,而POD活性则在-10℃处理时有所升高;-13℃以后各处理芽中PPO和POD酶活性与对照相比明显升高,而总酚含量和PAL酶活性显著降低。12月10日和20日冰冻处理变化趋势与11月30日基本一致,只是-13℃以后各处理芽中PPO和POD酶活性显著高于11月30日相同处理,而总酚含量和PAL活性则显著低于11月30日相同处理。冰冻处理可能是通过使PAL酶活性降低,PPO和POD酶活性的升高,加速酚类物质的氧化,从而使桃芽中总酚含量快速下降。不同短时间冰冻低温处理桃芽的萌芽级数和总酚含量之间的相关性分析表明,短时间冰冻处理可有效解除芽自然休眠,促进总酚含量降低。更多还原

【Abstract】 The experiment had been carried out in Taian Qunxing orchard from 2005 to 2007 with 7-year-old nectarine trees of cv Shuguang(Prunus persica var. Nectarina.cv.Shuguang). The effects of short-term freezing at different temperature on the endodormancy breaking of peach buds were studied. The main results were as follows:1. Short-term freezing at the rest temperatures significantly released the peach bud endodormancy. When the plants were entering dormancy, an effect of short-term freezing was observed only if a sufficient level of dormancy had been reached, which appeared to be when chilling reached two-thirds of chilling requirement or more for P. persica. Short-term freezing at -4℃and -7℃showed little effect on the endodormancy release in P. persica, but short-term freezing at the rest temperatures efficiently released the peach bud endodormancy. Effects of short-term freezing on the release of dormancy were advanced by the postponement of treatment date, the decrease of treatment temperature and the prolonging of treatment time. Some buds died in the short-term freezing treatment, whereas the effects of short-term freezing on the dormancy breaking in the survival buds were significantly advanced.2. On November 30, compared with non-freezing treatment (CK), the effects of -4℃and -7℃freezing treatment were almost the same as CK, the bud burst, the ratio of free water to bound water and membrane permeability were nearly the same as CK. But the rest freezing treatments advanced the date of endodormancy release, the bud burst, the ratio of free water to bound water and membrane permeability were higher than CK. On December 10 and December 20, the effects of the freezing treatment on endodormancy release were the same as the treatment on November 30, and the effect was better as the treatment was later. The correlation between the rate of bud burst, the ratio of free water to bound water, and membrane permeability of the different freezing treatments indicated that the change from bound water to free water and the increase of membrane permeability were probably the signal of dormancy release.3. On November 30, the chang of content of soluble sugar and the content of starch were almost the same as CK on -4℃and -7℃-freezing treatments. Whereas the rest-freezing treatments had the significant effects that the content of soluble sugar was higher and the content of starch was lower. On December 10 and December 20, the effects of rest-freezing treatments on dormancy release were the same as the treatment on November 30, and the effect of the former was superior to the latter. The correlation between the content of soluble sugar, the content of starch and the rate of bud burst of the different freezing treatments indicated that the transition of starch to soluble sugar was probably the charctristic of dormancy release.4. On November 30, -4℃and -7℃-freezing treatment nearly had the same results as CK on the following factors, including the rate of production in O2-·and·OH, the content of H2O2 , the activity of CAT ,SOD and POD enzyme .But all of them were higher than CK on the rest-freezing treatments except that the activity of SOD enzyme was lower. On December 10 and December 20, the effects of freezing treatments on dormancy release were the same as the treatments on November 30, and the effect of the former was superior to the latter. The significant increase of reactive oxygen content and production rate were probably the cause of dormancy release.5. On November 30, compared with CK, the content of total phenolics , the activity of PPO and PAL enzyme showed little difference at -4, -7 and -10℃, but the activity of POD enzyme became higher from -10℃-freezing treatment. The rest freezing treatments had the significant effects on them, and the activity of PPO and POD enzyme were higher than CK while the content of total phenolics and the activity of PAL were lower. On December 10 and December 20, the effects of the freezing treatment on dormancy release were the same as the treatment on November 30, and the effect of the former was superior to the latter. The correlation of the bud burst rate and the content of total phenolics of the different treatments indicated that short-term freezing significantly released the peach bud endodormancy and played down the content of total phenolics through reducing the activity of PAL enzyme and increasing the activity of PPO and POD enzyme.更多还原