Studies On The Regulation Of S₃₃₀₇ Applied To Seed And Nitrogen Level On The Growth Of Root And Relation Between Roots And Shoots In Winter Wheat

The regulation of Uniconazole ( S3307 ) applied to Seed with different concentration (0, 10, 20, 40 mg/kg) and nitrogen levels (90, 180, 270 kg/hm2) on the development of winter wheat root and shoot was studied by combination experiments of yield and soil column culture. The results are showed as followings:1. Uniconazole inhibits the growth of shoot and promotes the growth of root simultaneously, decreases the leaf area of middle and private leaves significantly (P0.05 r P<0.01), the higher of the concentration, the less of the main stem leaf area. But with higher nitrogen level, the inhibition is decreased and the tiller growth is promoted. Uniconazole treatment increases the leaf area of the flag leaf and the reciprocal second leaf. The flag leaf and the recoprocal second leaf for Uniconazole treatment are significantly higher than that of control. Except the third leaf stage in which the weight of fresh root pre plant is decreased, other stages in which the weight of fresh root and secondary roots.2. The total 32P radioactivity in S3307 treatment is more than that in control, and significantly promotes the 32P transfer to tillers. In the filling stage , the total 32P radio activity in the middle (20-40 cm) and lower ( >40 cm) roots are more than that in the upper roots. Uniconazole treatment promotes the distribution to the spike and active leaf.3. Uniconazole treatment promotes CO2 assimilation, improves the distribution of 14CO2 assimilate from leaf to spike and root. The total 14CO2 radioactivity in tillers treated by Uniconazole is more significantly (p<0.05) than that in the control. In middle filling stage, Uniconazole treatment promotes the49distribution to the spike and active leaf, especially in the middle and lower roots.4. The sencsnce process of wheat plants could be adjusted by Uniconazole and nitrogen treatmented by prolong the slow decline phase of photosynthesis in the flag leaf, the chlozophyll, leaf area per plant and root activity, increasing nitrate reductase (NR) activity in root and flag leaf after anthesis, inhibiting malondialdehyde (MDA) accumulation and membrane peroxidization in some extent.5. S3307 treatment increases grain number per ear, the ears per hm2 significantly, and duration of linear grain in grain weight is prolonged by Uniconazole and N treatment at pistal-stamen formation and tetrad stage, i.e. the grain filling phase is prolonged, so that grain weight and yield are incraesed significantly. The 20 mg/kg S3307 concentration on the 180 kg/hm2 N, the 40 mg/kg concentration on the 270 kg/hm2 N got the best results.6. Protein content in grain, the flour extraction , the wet gluten content ,the development time , the stability time ,the zeleny sedimentation volume,and the the breakdown time was raised when applying S3307 .S3307 treatment decreased the degree of softening and the mixing tolerance index , and improved the valorimenter value.