Screening Of Appropriate Amount Of Nitrogen Fertilizer On Different Genotypes Of Wheat

In order to determine the appropriate nitrogen application rate of different genotypes of wheat,two different genotype of wheat varieties of N50222 and LX987 were choosed as experimental materials.Four nitrogen rate treatments?0,100,200,300 kg?hm-2?were set to provide theoretical basis for the reasonable application of nitrogen in different genotypes of wheat from yield and quality.The results showed that the increased nitrogen application changed the individual dry matter accumulation and decreased the grain weight of the two varieties of wheat and this effect varied with genotypes.With the increase of N,the transferred matter in LX987 from vegetative organs to grain and contribution to grain firstly declined and then increased,while N50222 were on the contrary.The grain grouting process was changed as the "S" type trend.With the increase of N application,wheat grain dry matter accumulation was suppressed.In the range of 0 ³00 kg?hm-2of N application,the grain yield showed a tendency of up then down in both two wheat cultivars,and reached the maximum at N100.In the starch of N50222,the amylose content was lower than 0.9%,and the total starch and amylopectin content were higher than that of LX987.The increasing nitrogen application decreased the starch content of both varieties of wheat.The size distribution of starch was in unimodal curve,and the volume and surface area distribution were in bimodal curves.With the increase of N application rate,the particle size and the starch distribution of starch grains were affected,and the internal structure of wheat starch was changed.The starch pasting properties were improved effectively by increasing nitrogen application,and the pasting characteristic parameters of LX987 were higher than that of N50222.The relative crystallinity of LX987 increased while the N50222 decreased.The correlation analysis showed that nitrogen fertilizer affected gelatinization properties and crystal properties by changing the grain composition and particle size distribution of starch,and then affected the quality of wheat starch.Theprotein and its components of the two varieties increased with the increasing of the amount of nitrogen fertilizer and N50222 protein content was higher than that of LX987.From the yield and quality,the appropriate nitrogen application rate of the two different genotypes of wheat was 100 kg?hm^-2.