Effect Of Row Spacing On Carbon And Nitrogen Metabolism And Grain Yield Of Two Winter Wheat Cultivars With Different Spike Types

Effect of row spacing on two winter wheat cultivars with different spike types was studied in order to improve the yield potential and resource utilization efficiency. Under field experiments, two cultivars including large-spike and multi-spike winter wheat were cultivated in growth season during 2005-2007 at Henan Agricultural University Research Station to evaluate the effects on Population Dynamics, Photosynthesis Characteristics, Nitrogen Metabolism and Grain Yield. Four row spacing was setted, they were 10cm, 15cm, 20cm and 25cm, represent as R1, R2, R3, and R4. The main results were as follow:1. There were effects on population developmental dynamic state and some photosynthetic physiological indexes under different row spacing of two winter wheat cultivars with different spike type. The results indicated that the tiller number of plant population and LAI showed a single peak-curve of two spike type winter wheat. The tiller number increased with the row spacing became narrower. The LAI of narrow row planting treatment were bigger than wide row planting treatment of lankaoaizao8, while yumai49 showed the contrary condition. The chlorophyll content and Pn in flag leaf gradually decreased with the grain filling course. The indexes under different row spacing showed that: R2>R1>R3>R4 with lankaoaizao8, and R3>R4>R2>R1 with Yumai49.2. The soluble sugar content in flag leaf of two spike type winter wheat increased first and decreased afterwards. For lankaoaizao8, the higher content was observed on wide row planting treatment compared with the narrow row planting treatment in the early filling stage, then it showed the contrary condition in the late filling stage. For yumai49, the highest content was observed on R3 treatment, and the lowest was R1 at the whole filling stage. The sucrose content in flag leaf was also showed a single peak-curve of two spike type winter wheat, for lankaoaizao8, the highest sucrose content was R2 treatment, the lowest was R4 treatment, and for yumai49, the highest sucrose content was R3 treatment, the lowest was R1 treatment. The soluble sugar content and sucrose content in grains decreased with days after anthesis of two spike type winter wheat. For lankaoaizao8, the soluble sugar content of narrow row planting treatment was higher in the early filling stage, but the wide row planting treatment was higher in the late filling stage. For yumai49, the soluble sugar content increased with the row spacing became wider. The sucrose content in grains of lankaoaizao8 decreased with the row spacing became wider in the early filling stage, then it showed the contrary condition in the late filling stage. As to yumai49, higher sucrose content was observed on wide row planting treatment compared with the narrow row planting treatment in the filling stage.3. The activity of SPS in flag leaf showed a single peak-curve. Lankaoaizao8 appeared the curve at 14d after anthesis, the SPS of R2 treatment was higher in the filling stage, R4 treatment was lowest. Yumai49 appeared the curve at 7d after anthesis, the wide row planting treatment was higher than the narrow row planting treatment in pre-filling stage and middle of filling stage, the result was contrary to it in the late filling stage. The activity of SS in grains gradually decreased with the grain filling course. For lankaoaizao8, the narrow row planting treatment t was higher than the wide row planting treatment, and for yumai49, the wide row planting treatment was higher. The content in grains of two wheat cultivars present"S"form dynamic. The starch content in grains under different row spacing of lankaoaizao8 showed R2>R1>R3>R4, the difference increased with the process of grain filling; and for yumai49, the wide row planting treatment was higher than the narrow row planting treatment, but the differences were not significant.4. The nitrogen content in flag leaf decreased with the grain filling course of two spike type winter wheat. In pre-filling stage and middle of filling stage, for lankaoaizao8, R2 treatment had the highest nitrogen content, the wide row planting treatment were lower; and for yumai49, the nitrogen content decreased with the row spacing became wider. In the late filling stage, the wide row planting treatment of both cultivars were higher,. NR activity in flag leaf decreased with days after anthesis. For lankaoaizao8, R4 treatment was higher in pre-filling stage, then R2 and R3 treatment were higher, but the wide row planting treatment of yumai49 were higher in the grain filling course. There were difference on GS activity in flag leaf of the two cultivars, lankaoaizao8 decreased in the grain filling course and the narrow row planting treatment was higher than the wide row planting treatment, but yumai49 showed a single peak-curve, the effect of row spacing was contrast to lankaoaizao8. The protein content in grains of lankaoaizao8 reached its peak point at 14d after anthesis, then present"V"form dynamic, but yumai49 present"V"form dynamic after reached its peak point at 7d after anthesis. Row spacing have the same effect on the cultivars, R2 treatment had higher protein content at 7d after anthesis, then the wide row planting treatment were higher in the middle and the late filling stage.5. Row spacing had a evident effect on C-N metabolic characteristics of two spike type winter wheat. The total amount of re-transported storage matter covers a great part to the dry weight. For lankaoaizao8, R2 treatment was higher on the total amounts of re-transported storage matter and the rate of remobilization; and for yumai49, R3 treatment was higher, but R1 was the lowest treatment to the two cultivars. The total amount of re-transported storage nitrogen was the determining factor of the grain nitrogen. The total amount of re-transported storage nitrogen of lankaoaizao8 showed R1>R3>R2>R4, the rate of remobilization were contrast to it. The total amount of re-transported storage nitrogen and the rate of remobilization of yumai49 increased with the row spacing became wider.6. The grain filling course of the two cultivars present"S"form dynamic. For lankaoaizao8, the dry weight under narrow row planting treatment was higher, then the dry weight under wide row planting treatment speeded up the process of increasing with the grain filling course, the dry weight increased with the row spacing became wider in the late filling stage. For yumai49, the wide row planting treatment had a higher dry weight than the narrow row planting treatment during the filling course. Under different row spacing form, the kernels per united area and grain yield of lankaoaizao8 show R2>R1>R3>R4, its 1000-kernal weight increased with the row spacing became wider, but row spacing form had little influence on the grains per spike. The kernels per united area of yumai49 decreased with the row spacing became wider, but the differences were not significant, the grains per spike, 1000-kernal weight and grain yield show R3>R4>R2>R1, but row spacing form had less influence on the 1000-kernal weight.