Physiological And Biochemical Characteristics Of Winter Rape And Its Flower Bud Differentiation And Differential Expression Of Root Protein

6 winter rape varieties with different resistance in the cold region in the Northwest were studied in terms of physiological and biochemical characteristics,dry matter accumulation, flower bud differentiation and changes of root protein. The main results are as follows:1.Accumulation characteristic of dry matter:According to the results on winter rapes ,with temperature at 10℃~5℃,dry mater is mainly translated to the roots, which will not continue until temperature at -10℃, while the diameter of roots and root ratio are still increasing, especially for the super-cold resistance LongYou6. With the temperature of critical point at -10℃,The process of dry matter accumulation of winter rapes are stopped , turning to winter dormant period. However,with the temperature rises at -4℃to 8℃in the following year, the roots of winter rapes start to growth primarily,such as the diameter of roots and dry matter are increasing, and then the dry matter translates to aboveground rapidly after turning green wheat .2.Changes of soluble protein content: The protein content in the leaf is higher by 15~20mg/g than that in the root throughout the growth stage of winter rape, and the changes have noticeable stages. Soluble protein content increases steadily in the root and the leaf before overwintering, with -10°C (falling point of soluble protein content) in the root and -5°C in the leaf; it tends to decline as a whole during the overwintering stage, from 35 mg/g to 20mg/g and starts to rise again after returning green.3.Changes of protective enzyme activity: The protective enzyme activity of the leaf is higher than that of the root throughout the growth stage of winter rape. Longyou6, a type of winter rape with strong cold hardiness, changes fast in protective enzyme activity. The protective enzyme activity in the root and the leaf gradually increases before overwintering, and decreases after the temperature drops, with -5°C falling point in root and -10°C in leaf; it tends to fall as a whole during overwintering stage, and begins to pick up after the temperature rises again, with a quick recovery about 15 days prior to returning green.4. Process Observed to Flower Differentiation of Winter Rapeseed Results showed that in Northwest cold arid regions flower differentiation of Winter rapeseed began at -2℃before winter and continued at -10℃when flower differentiation came into the petal primordia and stamen primordium stages. When temperature dropped to -15℃the differentiation slowed down or even stopped. After winter flower differentiation restarted when temperature rose to -4℃to 10℃, and it went faster as temperatures rose. A flower differentiation completed in ten days.It is found that in China Northwest cold arid regions high yield cultivation of Winter rapeseed should be executed before winter. Study on the flower bud diffferentation of different type winter rapeseeds,it shows that the cold resistance ofLongyou6,74-1,Shangdang,Tianyou4 are strong ,especially Longyou6 which is Ultra strong cold resistance cultivar,early development,high regreen rate and slow flower bud diffferentation. B.napus flower bud differation is later that B.rape,generally starting after turning green wheat. So divide the flower bud differentiation of winter rapeseeds into three of the seven small period according to the heart in order to differentiate. 5.Root protein expression difference of winter rape: research results show that the Tris-HCl method can better avail the analysis of the root protein by two-dimensional gel electrophoresis, and 1000ug sample is better, and more than 1200 protein spots can be detected. There is a big difference in the root protein between Longyou6(super cold resistance variety) and Tianyou4(cold hardiness variety) under low temperature stress. Of the 1200 detected protein spots, there are 130～170 differential protein spots between Longyou6 and Tianyou4.