休闲期耕作对旱地小麦籽粒蛋白质形成及其相关酶活性的影响

为给旱地小麦高产优质栽培提供理论依据,通过大田试验研究了旱地小麦休闲期不同时间深翻、深松对0～300 cm土壤蓄水量、小麦籽粒蛋白质形成及其与氮代谢相关酶活性关系的影响.结果表明,休闲期深翻或深松均可提高旱地小麦播前0～300 cm土壤蓄水量,且欠水年效果明显,以前茬小麦收获后45 d深翻效果较好.休闲期耕作均显著提高了小麦蛋白质产量.耕作时间对籽粒蛋白质含量的影响因降雨年型不同而异,欠水年的休闲期耕作均显著降低了籽粒蛋白质含量；丰水年在麦收后15d耕作显著降低了籽粒蛋白质含量,而麦收后45 d耕作则显著提高了籽粒蛋白质含量,尤其显著提高了醇溶蛋白和麦谷蛋白含量,从而改善了品质.此外,丰水年麦收后45 d耕作可提高花后旗叶和籽粒谷氨酰胺合成酶(GS)活性、旗叶和籽粒谷氨酸合成酶(GOGAT)活性,降低花后旗叶和籽粒谷氨酸脱氢酶(GDH)活性；籽粒蛋白质的累积在麦收后15d耕作条件下与籽粒GDH活性关系密切,而麦收后45 d耕作条件下与旗叶GS和GOGAT活性相关性较大.总之,旱地小麦休闲期耕作在不同降雨年型下均可起到良好的蓄水保墒作用,且欠水年效果较明显；耕作时间对土壤水分、小麦氮代谢酶活性、籽粒蛋白质及其组分含量具有较大的调控效应,休闲期雨后耕作有利于籽粒蛋白质形成,且深翻效果较好.

Effect of Tillage in Fallow Period on Grain Protein and Its Related Enzyme Activity in Dryland Wheat

This field experiment was conducted to study the effect of deep tillage and deep scarification in fallow period at different time on soil water storage at the depth of 0~300 cm, protein accumulation and the relation between protein formation and related enzymes of nitrogen metabolism of dryland wheat. The results showed that soil water storage at the depth of 0~300 cm was improved by tillage in fallow period, especially in dry year and deep tillage at 45 days after wheat harvest had better effects on soil moisture conservation. Tillage in fallow period significantly improved protein yield of wheat. In years with different types of rainfall, tillage at different time had various effects on protein content of wheat grain. In dry year, tillage in fallow period significantly decreased protein content of wheat grain. In rainfall abundant year, tillage at 15 days after wheat harvest significantly decreased protein content of wheat grain and tillage at 45 days after wheat harvest significantly improved protein content of wheat grain, especially improved the contents of gliadin and glutenin. In addition, in rainfall abundant year, tillage at 45 days after wheat harvest could improve the activity of GS and GOGAT and decrease the activity of GDH in flag leaves and grains. The result also indicated that in the condition of tillage at 15 days after wheat harvest, there was a close relationship between protein content and the activity of GDH in grains. But in the condition of tillage at 45 days after wheat harvest, there was a high correlation between protein content with the activity of GS and GOGAT in flag leaves. The above results suggested that tillage in fallow period had better effects on soil moisture conservation in years with different types of rainfall. Tillage time had great regulation effects on soil water storage, the activity of nitrogen metabolism enzyme, protein ingredient content and protein content. Deep tillage after rainfall benefited the formulation of grain protein and improved the quality of dryland wheat.