Study On Root Growth, Yield And Quality Of Spring Wheat Under The Nitrogen Control Environment

Spring wheat was one of the important ecological type in China. Heilongjiang Province was the main producing area of spring wheat in the Northeast,although spring wheat area declined in recent years, it was the main crop of the northern partial area, and it was an indispensable member for the implementation of crop rotation system.Due to years of emphasis on increasing production and ignoring the quality improvement,which resulted in the poor quality of wheat and lacking market competitiveness. In recent years, more and more attentions were foused on the physiological function of root system was taken associating with the root morphological and physiological traits, which becaming an important indicator to measure root growth situation.The situation of root growth was a certain extent to reflect the strength of the crop nutrient absorption capacity,the higher of the root activity,the stronger of the ability to absorb nutrients.Soil fertility and level of fertilization also had a significant role in the regulation of soil fertility high root activity on wheat root activity.Nitrogen was the important measure regulating the crop growth, group development, the capacity of assimilation improvement and water using efficiency promotion.Nitrogen applied to farmland and in the soil were to be absorbed to plants through the roots, the root growth conditions and absorption of nitrogen. In recent years, the study showed that the root was gradually increasing, however, previous studies were concentrated in the pot and hydroponic conditions, was rarely reported in the field conditions that effect of nitrogen application on wheat root growth and yield quality.In this study, Longmai26and Longmai33were used as the experimental materials, exploring the effects of nitrogen application on spring wheat root growth and grain yield and quality in the field conditions. The root growth-related indicators at different stage and grain yield quality indexes at the maturity stage were identified and analysed.In order to aim the response to nitrogen-regulated for the spring wheat root growth, yield and quality formation, further establish the appropriate nitrogen level of spring wheat root growth, provide a theoretical basis and technical support for reasonabe application of nitrogen fertilizer in wheat production.The results showed that nitrogen application of45,60,75,90and105kg· hm-2:1. Right amount nitrogen fertilization could effectively improve the morphology and distribution of wheat roots, and enhance root physiological activity, thereby increase the absorptive capacity and utilization of the roots for moisture and nutrients.2.Nitrogen had a significant effect on spring wheat yield and component factors.Increasing the amount of nitrogen fertilization in a certain range could effectively promote the grain yield,effective panicles of per unit area and1000grain weight, there was a downward trend when the amount of nitrogen fertilization was excessive,however, spikelets per panicle had a increasing trend all the time.In this study, Longmai26had best yield of nitrogen application of90kg ha (N4treatment), up to3868kg·ha, Longmai33had best yield of nitrogen application of75kg ha(N3treatment),up to4067kg·ha.3.Nitrogen significantly affected the nutritional quality of spring wheat and processing quality,increasing the nitrogen application could effectively promote the grain protein content and protein yield, and nitrogen significantly affected wheat grain protein components content, the proportion of albumin, globulin and glutelin showed an increasing trend with the amount of nitrogen increased, the proportion of gliadin showed a downward trend with the amount of nitrogen increased, wheat grain starch content showed a downward trend with the amount of nitrogen increased, Nitrogen application significantly affected wheat grain bulk density, wet gluten content, very significantly affected settlement values,and nitrogen fertilization within a certain range could effectively improve the grain bulk density, wet glutencontent and sedimentation value, but would bring it down to excessive amount application of nitrogen fertilizer.4.Under the condition of nitrogen environment,root morphological indicators and physiological activity had a close relationship with grain yield and quality.Root growth indicators (except root shoot ratio and root average diameter) were significant or extremely significant positive correlated with yield;number of secondary roots,root average diameter,root vigor and key enzyme of root nitrogen metabolism were significant and extremely significant positive correlated with protein content and protein yield, root shoot ratio was extremely significant positive correlated with starch content;root activity was significant positive correlated with grain bulk density;the correlation between root growth situation and sedimentation value and wet gluten content were not significant.