| In recent years, the wheat production area gradually declined in Heilongjiang province, total cultivated area is less than400thousand hm-2, poor quality and low output is the main reason of low benefit, so there are big sowing density and high fertilizer which result in many problems such as lodging, reduction, and poor wheat quality. This study discuss that the regulatory means of high quality and yield population for Heilongjiang province spring wheat which is located in the high latitude, and compare the influence of spring wheat yield formation quality of two main spring wheat varieties, including Longmai26and Kenan16, the population density and the content of silicon. The wheat population was designed from300to900million hm-2under each three levels of fertilization, including105,180and225kg·hm-2and five levels of the silicon contents were analyzed under above population density.To uncover the effects of fertilization and population density on yield and processing quality of spring wheat, the physiological indexes involved in photosynthesis and senescence and relationship between them were analyzed under three treatments for two strong-gluten and medium-gluten spring wheat varieties, including the fertilization content. The main physiological processes investigated comprised photosynthetic characteristics and allocation of photosynthetic products; matter accumulation in organs, absorption and utilization of nitrogen, phosphorus and potassium. The important results were as follows:As population density increases, the peak time of leaf area index advanced, the net photosynthetic rate caused by the increase of non-stomatal limitation showed decreases first and then increases, the index of photosynthesis allocation each organ and dry weight were reduced, resulting in the decrease of the root shoot ratio. The increase of fertilization could reduce the stomatal limitation with net photosynthetic rate increased, improve photosynthetic distribution index of stems and leaves, promote matter accumulation in each organ. Compared with the strong-gluten wheat, Medium-gluten wheat showed that higher distribution index in roots and leaves, improvement of rapid formation of photosynthetic tissue in the prophase of growth and delaying the senescence of stem and leaf at late stage of growth.Higher population density resulted in restricting the accumulation and transportation of nitrogen, phosphorus and potassium of upside wheat, reducing agronomic efficiency of nitrogen, and improving the production efficiency of nitrogen phosphorus potassium and nitrogen harvest index.Fertilization level and promote the potassium to shoot transport, improve leaf nitrogen transfer efficiency and nitrogen agronomic efficiency, increase the organ of nitrogen phosphorus and potassium accumulation amount, reduces the nitrogen harvest index, but the middle level of nitrogen phosphorus and potassium fertilizer under the highest production efficiency. Strong gluten wheat has higher than medium gluten wheat nitrogen transfer efficiency, therefore, the latter contents of nitrogen phosphorus and potassium were higher, while production efficiency of nitrogen phosphorus and potassium and harvest index of nitrogen were lower than the former.The total soluble sugar of wheat leaf showed a single-peak curve along with population density, the increasing fertilizers decreased C/N for strong-gluten wheat, and improved C/N for medium-gluten wheat; suitable high density population ensured the number of harvest spikes of medium-gluten wheat, but made the restriction of formation of strong gluten wheat individual yields. Under suitable planting density, the increase of fertilizer amount improved photosynthate distribution of the filling stage wheat, and delayed leaf senescence during maturity, the former was useful to increase number of grains, the latter was useful to increase grain weight.Population density increased accelerated the leaf senescence, resulted in stomatal closure, the improvement of antioxidant enzyme activity, reducing transpiration rate, and net photosynthesis rate by non-stomatal limitation. During grain formation stage, the ratio of carbon to nitrogen that because of total soluble sugar accumulation, while nitrogen content declined, suffered imbalance of cause the increase of1000-grain weight, and the decrease of grain number. The competition of previous both factors produced directly the results that the increase of bulk density, the decrease of gluten quality, and the deterioration of characteristics of flour quality and dough stretching in the process of the quality formation. The increase of fertilization amount could alleviate the adverse effects of the high population density effectively.Basic fertilizer silicon caused the change of the photosynthetic area and capacity synchronously, resulting in improving photosynthetic rate and distribution index of photosynthate before the flowering, stimulating matter accumulation of vegetative organs, but for the increase of distribution index of the nutritional organs generated the decrease of spike material input of medium-gluten wheat after flowering. Basic fertilizer silicon below60kg-hm2(SiO2), the photosynthetic rate was improved for the enhanced for the improvement of non-stomatal limitation factors mainly, while above60kg-hm-"(SiO2) the photosynthetic rate falled because of the decreases of stomatal conductance and water use efficiency.The efficiency of spring wheat of nitrogen, phosphorus and potassium was enhanced for basic fertilizer silicon, but nitrogen transfer efficiency of wheat stem and leaf was decreased to cause the depression of nitrogen harvest index. On the basis of silicon fertilizer, the synergistic effect of the absorption and accumulation of nitrogen phosphorus and potassium presented, as well as antagonism in the organ level, and antagonistic relationship exhibited larger differences with different cultivars.Basic fertilizer silicon helpfully increased the spike length and density to change the spike traits of strong-gluten wheat; simultaneously promoted wheat photosynthetic carbon assimilation after blossoming, and the total soluble sugar content from source organs, which could supply adequate nutrition for capacity formation. Silicon helped to coordinate source, reservoir, flow of spring wheat during kernel formation, thereby wheat yields were heightened for improving seed rate and grain weight. In addition, silicon facilitated the nitrogen metabolism of wheat source organs after flowering to improve flour processing qualities, for example, improvement of grain gluten quality and flour water absorption rate, elongation of dough breakdown time, tensile resistance and tensile ratio. For medium-gluten wheat, basic fertilizer silicon could expand production capacity of population by increasing the number of harvested spike, but affect quality of spring wheat un-significantly.Wheat protein family involved in silicon transporter was identified by analysis of homologous sequence. Four members of family with NOD26-like membrane integral structure named respectively TaNIP2;1, TaNIP2;2, TaNIPad4;1and TaNIP1;1. Phylogenetic analysis showed that, except for TaNIP1;1protein belonged to subgroup NIP â… , others were classified into subgroups NIPâ…¡.TaNIPs expression patterns were divided into two groups based on analysis of ESTs database and qPCR. Both TaNIP1;1and TaNIP4;1expressed mainly in flower and inflorescence; while both TaNIP2;1and TaNIP2;2expressed principally in root and shoot. The effects of silicon on plant height and dry weight of upper plant significantly were found, and silicon accumulation in leaves almost depended on the silicon content. The expression change of TaNIP2;1å'ŒTaNIP2;2were weak exposured to the different content silicon, and the correlation with silicon accumulation was not obvious. |
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