| In winter the temperature of heilongjiang is extremely low, so winter wheat planting is restricted in the cold area of northern China, such as Heilongjiang province.Winter wheat is the main cultivated wheat varieties in our country, compared with spring wheat, which has advantages of high quality, early maturity, adjusting farming. There are two types of wheat: winter wheat andspring wheat. The stable security overwintering of winter wheat in Heilongjiang has been an important issueof winter wheat breeding. DM1 is selection of the northeast agricultural university With strong cold resistance, The winter wheat varieties DM1 at-30 ℃ low temperature conditions for safe wintering. DM1 have some advantages, such as long growth period, good yield and quality, superior resistance to cold and then.The biggest breakthrough of DM1 is that live in-30℃~-45℃ temperature through the winter in cold conditions of Heilongjiang Province, DM1 showed strong resistance to cold.The main reason is the growth of the field DM1 cold acclimation is not sufficientin in the fall of 2011, because of de-acclimation occurred in cold acclimation period.The Survival rate of DM1 less than 20% in the secont year.So study for cold acclimation of winter wheat along with different temperature de-acclimation treat of the winter wheat of low temperature treatment is of great significance.In this study, two different cold of winter wheat cultivars were carried out in the field and laboratory tests, Research de-acclimation and cold treatment were occurred in cold acclimation phase, and then determination of the survival rate and physiological characteristics of winter wheat under different treatments, this could provide a theoretical basis for the cold winter to winter wheat breeding. The main results of this study are as follows:1.In five sampling under the different treatment, the survival rate of anti-cold varieties DM1 is higher than cold sensitive varieties JM 22, In October 31(cold acclimation 20 days) the winter wheat has already been fully domesticated under the natural conditions.the lowest survival rate of cold resistance variety(DM1) in 20℃during de-acclimation two days and then-12℃ three days,Survival rate range of 0%-65% in each sampling, the anti-cold varieties JM 22 survival rate was 0%in this treatment on November 5.There was greater impact on sensitive varieties JM 22 in 20℃during de-acclimation two days and then-12℃ three days,the survival rate range of 0%-40% in each sampling, the sensitive varieties JM 22 survival rate was 0%in this treatment on November 5. There was little effect with 10℃during de-acclimation two days,and the survival rate of de-acclimation will be higher than acclimation in some sampling date the survival rate is 75%- 100%.2.The heaviest damage of anti-cold varieties DM1 and sensitive varieties JM 22 both in 20℃during de-acclimation two days and then-12 ℃ three days, and has the maximum relative conductivity.When DM1 de- acclimation temperature and low temperature are the same,The longer the duration of the cold treatment, the higher of the relative conductivity.3. Membrane lipid peroxidation is the worston anti-cold varieties DM1 and sensitive varieties JM 22 in 20℃during de-acclimation two days and then-12℃ three days, the worst of membrane lipid peroxidation occur on November 5 with anti-cold varieties DM1 and sensitive varieties JM 22.4. When two test species in de- acclimation temperature and low temperature are the same, The longer the duration of the cold treatment, the lowest of SOD Enzyme activity.When the de-acclimation occur in the early of cold acclimation, the SOD Enzyme activity will high,the de-acclimation of later occurrence,the lower of SOD Enzyme activity, the highest of SOD Enzyme activity with DM1 occurred on October 31.There is no significant variation on anti-cold varieties DM1 POD Enzyme activityin five sampling with different the treatment, the difference was not significant between each treatment October 21(P<0.01).The highest POD Enzyme activity of sensitive varieties JM 22 in 10℃during de-acclimation two days and then-12℃ one day on October 21 and 26.The highest of POD Enzyme activity with winter wheat are in no de-acclimation on November 5 and 10.5.The content of GSH of anti-cold varieties DM1 are higher than sensitive varieties JM 22 in cold acclimation period. The highest GSH content of anti-cold varieties DM1 occurred after-12℃ three days;After October 26,both the anti-cold varieties DM1 and sensitive varieties JM 22 are show that The higher of temperature in de-acclimation and low-temperature duration, the lower of GSH content.6.After low temperature and de-acclimation treatment, Soluble sugar and Sucrose content of anti-cold varieties DM1 are higher than sensitive varieties JM 22.After de-acclimation treatment, the anti-cold varieties DM1 and sensitive varieties JM 22 Soluble sugar and sucrose content are decreased. The biggest impact on the content of soluble sugar on two test species are in 20℃during de-acclimation two days and then-12℃ three days. |
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