Effects Of Density And Nitrogen Levels On Nitrogen Metabolism And Yield,Quality Of Triticale

From the cultivation techniques of triticale around China, we know most species Introduction region adequately utilizes the characteristics of triticale with strong resistance,However, the concrete control measures about triticale has not been fully explored and explained. The case study was carried out in 2006~2008, two triticale cultivars octaploid Dongnong5305 and sextuploid Dongnong96026 were selected. There were two factors in the experiment: nitrogen application (N) and density treatment (D).Four nitrogen applications were as follow: 0kg/hm2(N0), 75kg/hm2 (N75), 150kg/hm2 (N150), 225kg/hm2 (N225). Three density treatments were namely D300 (3million basic seedling per hectare), D450 (4.5million basic seedling per hectare), D600 (6million basic seedling per hectare).The study analyzed the changing law of triticale growing development, photosynthetic characteristics, grain yield and quality, enzymatic activity about nitrogen metabolism under different density and nitrogen application. Besides, physiological basis of grain yield and quality in different ploidy triticale has been discussed to provide the theory base and technical approach for improving triticale grain yield and quality and giving directions to cultivate different ploidy triticale.1. Fertilizing properly and reducing the density can increase the percentage of earbearing tiller and grain yield of triticale.Determining the appropriate number of basic seedlings can control the nonbearing tillering being produced before jointing stage and reduce the ratio of peak tillering to final spike number and increase percentage of earbearing tiller to attain the high output. The total number of stems per hectare increased with density increasing from the tillering to the maturity, but the percentage of earbearing tiller of Dongnong5305 decreased with density increasing in mature period, while the percentage of earbearing tiller of Dongnong96026 first increased then declined. The total number of triticale stems and the percentage of earbearing tiller during growth periods were higher than that of control treatment N0.In the same density, percentage of earbearing tiller of the two varieties both presented increased then downward with the nitrogen increased., thereinto the tiptop of the two respectively presented to: D300N75 treatment of Dongnong5305, D450N150treatment of Dongnong96026, and This is when the highest yield attained.2. The main direction should be angled In order to attain good harvest in different ploidy triticale. Dongnong5305 which has the higher tiller capability should appropriately reduce the number of basic seedlings and the level of nitrogen and increase grains/ear and kernel weight. Based on the suitable group controlled, Dongnong96026 should apply nitrogen fertilizer properly and coordinate yield component to realize the high production. The spike number of the two varieties increased with the density increasing, however, grains/ear and kernel weight with opposite effect. With the increasing of nitrogen fertilizer application, the spikes per hectare and the number of grains per spike of the two varieties presented increased then downward, and grain weight reduced. The result showed that the number of productive ear increased significantly with the density increasing which produced negative effects to grains/ear and kernel weight. The density was so high that the added spikes could not counteract the reducing of the number of grains per spike and 1000-grain weight, the yield did not rise but lower. The increasing of the number of productive ear and grains/ear made up for the lower grain weigh that beneficial to yield improvement. Density and fertilizer has produced an obvious effect on grains/ear compare to grain weight.3 Suitable density and nitrogen fertilizer level were favorable for improving the photosynthetic capacity of triticale.In early growth stages, the density treatment in Dongnong5305 was slightly higher than the other treatments. Low density treatment in Dongnong96026 has higher comparing to the other treatments. With the growing process postponed, the decline rate at high density treatment was bigger. Chlorophyll content reduced with density increasing, 28d after flowering Dongnong5305 at low density was significantly higher than high density. With the increased nitrogen rates, the overall trend of chlorophyll content was first increased then declined, photosynthetic rate showed consistent rule with chlorophyll.Proper density and nitrogen application improved light conversion efficiency and the potential activity of PSâ…¡on the one hand, on the other hand, inhibited the non-photochemical dissipation, excessive nitrogen was not conducive to improving photosynthetic characteristics. Dongnong5305 photochemical quenching coefficient at low-density was higher than the medium-density and high-density treatment in growth periods.Dongnong96026 photochemical quenching at the medium-density was highest under different levels of nitrogen fertility treatment in growth periods .The two varieties photochemical quenches coefficients which under various nitrogen treatments was higher than contrast N0,Dongnong5035 flag leaf got the highest electronic transfer activity with N level 75kg/hm2. Dongnong96026 showed the highest photochemical quenching with N level 150kg/hm2. The lowest non-photochemical quenching of the two varieties that under various nitrogen treatments in growth periods respectively presented to: low-density treatment of Dongnong5305, medium-density treatment of Dongnong96026. The smallest non-photochemical quenching of the two varieties were respectively: N level 75kg/hm2 of Dongnong5305, N level 150kg/hm2 of Dongnong96026.4 Reducing the density and proper nitrogen application could improve grain quality of triticale. Reducing the density and proper nitrogen application increased grain protein content. Grain protein content of Dongnong5305 brought down with the density increasing during maturity stage, grain protein under 3 million basic seedling per hectare was highest; while grain protein of Dongnong96026 under 4.5 million basic seedling per hectare was highest. Grain total protein content of each nitrogen application treatments were higher than N0 treatment under different density treatment of two varieties. Grain protein content reduced with nitrogen application increased from 150kg/hm2to225kg/hm2. Reducing the density increased grain albumin and globulin content while increasing the density decreased gliadin and glutenin content; four protein components content in grains increased then decreased with nitrogen application increased, increasing nitrogen application properly could effectively increase protein components content, regulative function of nitrogen on gliadin and glutenin content was more obvious than on albumin and globulin content, interaction effects of density and nitrogen fertilizer was better than effect of nitrogen fertilizer.Amino acids content of each nitrogen application treatments were higher than N0 treatment in two varieties. Amino acids content of N225was lower than that of N150. Amino acids content reduced with the density increased under the same nitrogen level,difference of amino acids content among nitrogen treatment was more obvious than that among density treatment. There was significantly positive correlation between lysine content and protein content during maturity stage in two varieties, the correlated relationship between amino acids content and protein content showed the same trend.5 Increasing the density was favorable to improve grain baking quality of triticale, effect of nitrogen varied from the ploidy of triticale.Grain volume wight of Dongnong5305 showed an increasing trend with the density increased, but the change of Dongnong96026 was not significant, nitrogen application significantly increased grain volume wight; wet gluten content of middle and high density were higher than that of low density, wet gluten content showed an indistinctive increasing trend with nitrogen application increased; falling number reduced under high density in two varieties, falling number of Dongnong5305 increased while that of Dongnong96026 decreased when nitrogen application increased. Increasing nitrogen application and density was favorable to enhance grain volume wight and wet gluten content; effect of cultivation measure on sedimentation number was little and varied from varieties; it could obtain higher falling number under middle density, effect of nitrogen on falling number varied from ploidy, increasing nitrogen application had a positive effect on octoploid but a negative effect on sextuploid.6 Reducing the density and proper nitrogen application guaranteed physiological basis for formation of high grain protein content.Increasing nitrogen application promoted nitrogen assimilation of leaf after flowering, reducing the density weakened degrading ability of protein. Increasing nitrogen application enhanced the activity of NR and GS and decreased the activity of endopeptidase and aminopeptidase in flag leaf; the activity of NR and GS in flag leaf decreased with density increased, the activity of NR and GS under D300 treatment was highest, the activity of endopeptidase and aminopeptidase increased with density decreased; soluble protein content in flag leaf had significant positive correlation with the activity of NR and GS, and had significant negative correlation with the activity of endopeptidase and aminopeptidase after flowering. N translocation amount,N translocation rate,translocation N contribution rate and N harvest index increased then reduced with nitrogen application increased in two varieties, effect of nitrogen had reached significant level. Grain protein content and yield showed a significant positive with N accumulation after flowering, enhancing storage N translocation amount before flowering could accumulate N of grain and significantly enhance grain protein content and yield; the correlation between N accumulation and translocation and grain protein components content showed that N accumulation and translocation was the key factor that enhanced protein components content, N accumulation was favorable to increase gliadin content, N translocation was favorable to increase albumin content, albumin and gliadin content was the important reason for increasing grain protein content.7 The result of identified by mass spectra verified the positive effect of increasing nitrogen application.7 Differential expression proteomes were found by MALDI-TOF-MS and bioinformatics analysis, these were proteome related with synthesis and signal transduction of protein, enzyme related with. Elimination of the free radical, proteome related with chloroplast growth and metabolism, enzyme related with carbon metabolism, enzyme related with nitrogen assimilation.The increasing of proteomes expression amount further showed that the effect of nitrogen on photosynthesis is based on the activation of photosynthesis relevant enzymes to adjust the plant photosynthesis, nitrogen could delay senescence of plant might be closely related with strengthening elimination of oxygen free radical; nitrogen not only played role in keeping photosynthesis performance but also strengthened information conduction and improved the resistance of plant; increasing of nitrogen directly promoted nitrogen metabolize and assimilate; nitrogen had positive impact on protein synthesis; Nitrogen overally affected on growth,substance metabolism and signal conduction of plant, identify and analysis on protein spots showed that the emphasis of its influence was functional proteins.