Research On Key Technologies Of Affecting Qualitative Traits Of Rape TCMS Two-Line Hybrid Seed In High Elevation Regions In Minle County

Minle county located in cold-cool irrigating area at the north of Qilian Montain,with cold and humid climate, large temp diff, abundance sunshine, large grain weight and high oil content. Besides it's an ideal two-line zone for production of hybrid seed rape TCMS with suitable summer temperatures, scarce rainfall and long time sunshine, rugged isolation in good condition.In the course of seed production in the field, we discovered that rape TCMS dual-use system in the area of hybrid seed breeding emerging the phenomenon of low germination potential.And the reasons for this phenomenon had seldom reported.Currently, the factors affected low seed germination potential had reported as follows:Temperature of seed maturity, seed dormancy, seed coat thickness, hormone content, soluble sugar content etc.In order to realize and solve this problem, this experiment gives a few preliminary research to a few vital factors which may lead to this phenomenon. According to this problem, the experiment was carried out in Liren and Caoying village, Lemin country, Gansu Province, using the combination of two rape combination. Important conclusions can be found in the following parts:1.Under indoor dry condition, rapeseed that harvested after flowering end 30d dry weight tended to stability during 9-12d,but other periods of rapeseed dry weight was still in the decline stage. Under outdoor dry condition, variation of rapeseed dry weight was very similar to under indoor dry condition. Under indoor and outdoor dry condition and with threshing time delaying, rapeseed dry weigh that harvested at the same time was gradually increasing. Rapeseed dry weight that under indoor condition was always higher than rapeseed dry weight that under outdoor conditions.2.Under indoor dry condition, rapeseed that harvested after flowering end 10d had the ability to germinate and rapeseed germination rate that harvested after flowering end 15d could reach more than 95%. Unde outdoor dry condition, rapeseed that harvested after flowering end 10d was not ability to germinate but rapeseed germination rate that harvested after flowering end 15d could reach more than 95%.With threshing time delaying, rapeseed germination rate increased gradually. Termed of the germination rate, rapeseed germination rate that under indoor condition was always higher than rapeseed germination rate that under outdoor conditions and the difference was the most obvious after flowering end 30d.3. In field conditions, outdoor drying method had a significant impact on the rape germination rate with different altitudes. Illumination effected on rapeseed germination rate showed increasing trend as the altitude increase.4.Elevation had a significant impact on the rape growing period, thousand grain weight, crude fat, germination rate and yield. Among them, the average growth period delayed 3.68 days, the average thousand grain weight increased 0.2g, fat content in an average increase of 2.40%, an average of 3.82 percent germination potential dropped, germination percentage dropped an average of 0.29%, yield (acres) increased by an average of 31.76kg, with every 100m increased in altitude.5. Using combine threshing, rapeseed breakage rate was 6.2%, thousand grain weight of 4.71g, while grinding machine of rapeseed damage rate was 0.5%, and thousand grain weight was 4.54g. Combine threshing rapeseed germination rate slightly faster than milled rapeseed.6.In Minle County, seed production base should be selected for the 2300m altitude along the Qilian Mountain region;Rape that harvested after end flower 25-30d was dryed by small bundles or casual in the sun and grinded machine.These technical measures were the key points to ensure high germination potential.