施氮水平对小麦籽粒淀粉粒分布与加工品质的影响

为明确施氮对小麦淀粉粒分布与加工品质的影响,选用强筋小麦藁城8901和弱筋小麦豫麦50为材料,分析了不同施氮水平下小麦籽粒淀粉粒分布特征与部分加工品质指标。结果表明,适量施氮(240kg.hm-2)显著提高籽粒B型淀粉粒体积百分比,过量施氮(360kg.hm-2)时小麦籽粒B型淀粉粒体积百分比降低。施氮水平对两个小麦品种籽粒A、B型淀粉粒数目百分比无显著影响。在施氮0～240kg.hm-2范围内,增施氮肥可以提高籽粒直、支链淀粉积累量,而过量施氮不利于籽粒直、支链淀粉的积累。小麦湿面筋、沉淀值、面团形成时间和稳定时间等参数与A型淀粉粒体积百分比呈显著负相关,与B型淀粉粒体积百分比呈显著正相关。适量施氮能使强筋小麦加工品质变优;增施氮肥导致弱筋小麦加工品质变劣。

Effects of Nitrogen Application Rate on Starch Granules Size Distribution and Processing Quality of Winter Wheat

Two wheat cultivars,Gaocheng 8901(strong gluten) and Yumai 50(weak gluten),were used to investigate the effect of nitrogen application rate on starch granules size distribution and processing quality in wheat grain,and the relationship between starch components and processing quality.The results showed that the medium nitrogen application rate led to a significant increase in volume percentage of B-type starch granules and a decline in those of A-type starch granules.While,the high nitrogen application rate led to a significant decline in volume percentage of B-type starch granules and an increase in those of A-type starch granules.Medium nitrogen application rate remarkably increased starch and starch components accumulation at the maturity,while high nitrogen application rate remarkably reduced starch accumulation in grain.Correlation analysis showed that test weight,sedimentation value,dough development time and stability time and extensibility was negatively related to volume percentage of A-type starch granules,and positively related to volume percentage of B-type starch granules.These results suggested that the ration of A-and B-type starch granules had possible effect on the processing quality of wheat grain.The medium nitrogen application rate improved grain processing quality for strong gluten wheat cultivars,but,nitrogen application worsened grain processing quality for weak gluten wheat cultivars in the ranges from 0 to 360 kg·hm-2.