氮素水平对藁城8901和山农1391籽粒品质的调控效应

选用强筋小麦品种藁城8901（GC8901）和弱筋小麦品种山农1391（SN1391），在池栽条件下，分别施纯氮12、24和36 g m^-2，研究了氮素水平对小麦籽粒品质的影响。结果表明，氮素水平对2个类型小麦品种籽粒淀粉、蛋白质性状和加工品质有较大影响。与12 g m^-2处理相比，24 g m^-2处理明显提高籽粒支链淀粉含量，降低直链淀粉含量和直支比，促进淀粉积累，改善淀粉的糊化特性。当氮素水平增加至36 g m^-2时，籽粒的支链淀粉含量降低，直链淀粉含量提高，淀粉积累量降低。随氮素水平提高，GC8901籽粒清蛋白、球蛋白、谷蛋白、总蛋白含量和蛋白质产量提高，而醇溶蛋白含量降低。SN1391以24 g m^-2处理的醇溶蛋白、谷蛋白和总蛋白含量最低；随氮素水平提高球蛋白含量提高，而清蛋白含量降低。适量施氮能提高籽粒硬度，但过量施氮则使其降低。籽粒容重随氮素水平提高而降低。增施氮肥能提高GC8901面粉白度，但SN1391以12 g m^-2处理最高，24 g m^-2处理最低。氮素水平从12 g m^-2增加到24 g m^-2，GC8901面筋含量、质量提高，面团形成时间、稳定时间、拉伸面积和延伸度增加，这有利于提高强筋专用品质；SN1391面团形成时间和稳定时间显著降低，筋力变弱，拉伸面积减小，弱筋专用品质得以改善。当氮素水平增加至36 g m^-2时，2个品种加工品质有变劣的趋势。研究表明，改变淀粉、蛋白质及其各组分含量，是氮素水平影响小麦加工品质的重要途径。

Effects of Nitrogen Application Rate on Grain Quality in Wheat Cultivars GC8901 and SN1391

Application of nitrogen fertilizer(N) is one of the most important measures to increase grain yield and improve the end-use quality of wheat.It is generally accepted that the protein content and nutrition quality of wheat grain could be improved by reasonable N application.But the effect of N rate on protein component and processing quality of wheat grain varied with cultivars and cultivation conditions.The strong-gluten wheat cultivars of wheat are obviously different from the weak-gluten cultivars in many quality parameters of grain,such as grain protein content,protein component,grain starch content,starch component.In the present study,a strong-gluten wheat(Triticum aestivum L.) cultivar GC8901 and a weak-gluten wheat cultivar SN1391 were used to investigate the effect of N rate on the grain quality.The experiment was conducted in a pool culture on the Experimental Farm of Shandong Agricultural University from 2002 to 2004 with three nitrogen application rates,12(N12),24(N24),and 36(N36) g m-2,respectively.The results showed that properties of starch and protein,and processing quality in both wheat cultivars could be markedly influenced by N application.As compared with the N12 treatment,the N24 treatment significantly increased amylopectin content,decreased amylose contents and the ratio of amylose to amylopectin,promoted the starch accumulation and improved the paste properties.When the N application rate reached 36 g m-2,amylopectin content and starch accumulation decreased,however,the amylose content increased.The albumin,globulin,glutenin and protein content of GC8901 enhanced,but the gliadin content reduced with the increase of N application.The gliadin,gluten and protein content of SN1391 were much lower in the N24 treatment than those in the other two N treatments.The albumin content of SN1391 decreased and globulin increased with the increase of N rate.An appropriate N rate was beneficial to increased grain hardness,but excessive N application had an adverse effect.The volume weight of wheat grain declined with the increase of N application.The dough whiteness of GC8901 rose with increasing nitrogen,but that in N24 treatment was lower than that in the other two treatments of SN1391.As for GC8901,with the increase of nitrogen application rate,the content and quality of wheat gluten,the development time,stability time,extension area and extensibility of the dough were all enhanced,leading to the improvement of food processing quality of strong-gluten wheat cultivars,but those for SN1391 were low resulting in the better processing quality of weak-gluten wheat cultivars.When the N application was 36 g m-2,the quality of two cultivars went inferior.The results reveal that the N application rate affects protein,starch,and their component contents in grain,resulting in the changes of the processing quality of wheat.