Study On Relation Ship Among Nitrogen Metabolism And Yield And Quality In Sping Wheat Under Low Seeding Density Cultivation

In order to make the further explore for the changing regulation of physiology characters and utilization efficiency under low seeding density cultivation of spring wheat, three spring wheat cultivars (lines) which have different protein content were selected for the experiment. We established two factors that is density (A) and nitrogen topdressing level (B). Three density treatments: A₁ is conventional treatment, had 6 million basic seeding per hectare; A₂ and A₃ are low seeding density treatments, separating had 4.5 and 3.0 million basic seeding per hectare. The topdressing level of N: B₁ 30kg/hm², B₂ 120 kg/hm², B-3 210 kg/hm². The study on the characters of spring wheat under low seeding density by field test indicated that:Low seeding density can enlarge the greenery area of flag LA, with the density and fertilizer changing, the trend of single plant in each period shows: the smaller the density and the higher the fertility is, the bigger the area and the photosynthetic rate and soluble protein content is.The accumulation and transportation amount of N are increase with the decrease of seeding density, the increase application of N and apply N at later growing stage. The accumulation of N of each cultivar under different density has significant differences at each period, low seeding density and and high fertilizer treatment made the maximum accumulation of N, and in the conventional treatment the accumulation is the minimum. Different single plant has different N accumulation, the result compared with three cultivars in same level is different: the treatment has the most obviously influence to Dongnong 122, to Longmai 26 the influence is less, and to 02-4256 the influence is the lest. In three cultivars, the protein content in each organ settled in order from big to small is: leaf blade>stem sheath>spike vegetative organ, which certified that leaves are the main organ for the accumulation of N, but at the later growing stage, because of the acceleration senesce speed of leaves, N is mainly stored in stem sheath.The low seeding density cultivation has no obviously influence to the change of NRA, but has significant influence to the strength of NRA. Under the same density, enhance the fertilizer amount of N or applying N at later growing stage can improve the NRA. Among three cultivars, the NRA of Dongnong122 is the highest, second is Longmai26, and 02-4256 is the lowest.As to the grain proten content, Dongnongl22 has significantly increased (A₃>A₂>A₁), in theother two cultivars the different is distinguish.The antimony of yield and quality is still exist, the...