| The peach (prunus persica) belongs to fallen leaf arbor of rosaceae, also is called peach-pit red, white peach, red peach etc. It is one of the fruits which people is fond of commonly nowadays. The peach is quite sensitive to the environment and has obvious regional distribution phenomenon. Not only mature period of fresh peach is short and concentrate, but fruit pulp does not extremely bear the storage and transportation, therefore, it is difficult in the ripe time for peach to sale abroad in the area of peach production, and lead to lower economic effect. In recent years, with the popularization and development of the fruit tree facilities cultivates, advancing or postponing fruit tree germ is important means for the improvement of economic results about fruit tree. Grasping dormant mechanism become the key technology, which inspire the people to study fruit tree dormancy once again. Gansu Province is original area of peach, great developing anti-seasonal peach cultivates will have significantly economical and social value. Therefore, the research makes use of three kind of late-maturing peach variety which is suitable to cultivate in the Lanzhou area being as experiment material, tries to study changes of PAL activity, production rate of NO, H2O2 content, CAT activity and POD activity in leaves and blossom buds, grasps function of the signal conduction matter such as SA, NO and H2O2 in peach dormancy, discusses dormant mechanism and the developing course of peach, and provides the certain theory basis for the dormant signal regulation. The mentioned above can help us find the method of the manual control dormancy advancement, and provide the theory instruction for the peach anti-seasonal cultivation. The main results are as follows:1. Under the Lanzhou climate condition, in 2006-2007 year the mid-maturing peach completed the natural dormancy in the midth of December (December 15th-December 25th), the late-maturing peach completed the natural dormancy approximately in the late-December (December 25th - January 5th).2. In the natural course of dormancy, the starch content was rapidly decline to the lowest value in the buds of three varieties, soluble sugar content is soaring to the highest value for December 15th-January 5th, coinciding with the time of relieving dormancy. Suggested that the rapid rising of soluble sugar content was as symbol of peach natural dormancy- release.3.Under the natural conditions, with the peach different growth period, the tendency of PAL activity, production rate of NO and H2O2 content in the leaves of three varieties were roughly the same, PAL activity, production rate of NO and H2O2 content in Shenyang No.2 with high chilling-requirement were higher than those in heroin peach with low chilling-requirement. Fall into the top scheduled period, production rate of NO and H2O2 content in the leaves increased significantly. Proved that the dynamic changes of production rate of NO and H2O2 content in leaves were related with the the peach tree being about to enter the dormancy. Noted that the dynamic changes among them was likely to a form of expression of stimulus when peach feel the outside conditions (such as light, temperature), and that of activating dormancy signal.4. In the natural course of dormancy, H2O2 content showed regular changes in the buds of three varieties, Along with the continuous deepening of dormancy, H2O2 content in dormant buds continuely rise, when reaching to maximum value, then quickly begin to decline, this time matched with the time of dormancy-release. Exogenous H2O2 and H2O2(hydrogen peroxide) inhibitor DMTU were used to treat Chongyanghong. Compared with CK, H2O2 treatment were able to advance about three days in breaking dormancy, and DMTU delayed dormancy two days.5. In the natural course of dormancy, production rate of NO showed regular changes in the buds of three varieties. In the early dormancy period (October 20th -November 1th), production rate of NO in flower buds was lower; In the end of dormancy period(December 15th -January 5th), production rate of NO rate had a rapidly jump, quickly reach to a higher value, this period were slightly earlier than the time of peach dormancy-release. Exogenous NO donor SNP and NO inhabitor NAME were used to treat Chongyanghong, SNP treatment raised production rate of NO in dormant buds, breaking dormancy was ahead of five days; NAME treatment decreased production rate of NO in the dormant buds, postponed releasing dormancy for two days.6. Along with the deepening of the course of dormancy, under natural conditions, PAL activity in dormant buds was gradually increased, and PAL activity rapidly reached to the highest value, conciding with the time of the peach tree through physiological dormancy time. By using exogenous SA to treat Chongyanghong, releasing dormancy was ahead of five to seven days, and the treatment also made the time of the appearance of H2O2 peak time be earlier 10 days than CK, which basically corresponded to the time of releasing dormancy.7. Extraneous NO donor SNP can remarkably activate PAL activity in the dormant buds, NO inhibitor NAME has the opposite result, indicated that the changes of PAL activity related with production rate of NO in dormant buds. Showed that NO might affect SA accumulation through activating the PAL activity. The experiment also showed that, SA transmits the dormancy signal for H2O2 is through SA unifing CAT(H2O2 main elimination enzyme), causing the H2O2 content rise. Noted SA participated in the advancement of NO regulating peach dormancy, which was possible playing a role in signal amplification in this process, transmitted to H2O2, then completed the entire advancement of regulating dormancy. At the same time, extraneous SA can also boost production rate of NO in dormant buds, proved SA and NO were not the simple chain type relations in the peach tree dormancy mechanism, but were a kind of more complexly mutual mechanism. Speculated that SA possibly changed vivo production rate of NO through some influence factors such as cis-aconitic acid enzyme, then regulated dormancy advancements through other way . |
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