土壤相对含水量对冬小麦氮素积累、蛋白质组成和加工品质的影响

Effects of Soil Water Content on Nitrogen Accumulation,Protein Composition and Processing Quality of Winter Wheat

为了解土壤相对含水量（SRWC）对冬小麦氮素利用和籽粒品质的影响,在防雨条件下,以高产强筋小麦品种皖麦38为材料,采用测墒补灌的方法,0-40cm土层SRWC在拔节期（J）设置65%、70%和75%3个水平,开花期（A）设65%和70%两个水平,分析了不同处理（分别用J65A65、J65A70、J70A65、J70A70、J75A65、J75A70）间冬小麦氮素积累、蛋白质组成和加工品质的差异。结果表明,在65%-75%范围内,随拔节期SRWC的提高,小麦开花期各器官的氮素积累量显著增加;J70A70处理的成熟期籽粒氮素积累量与J75A65和J75A70处理无显著差异,但显著高于其他处理,且其氮素收获指数最高。开花期SRWC相同时,拔节期SRWC 65%处理较SRWC 70%处理具有较高的贮藏蛋白含量和谷醇比以及较低的可溶性蛋白含量;J65A65处理的籽粒谷蛋白含量、谷醇比和贮藏蛋白占总蛋白的比例显著高于其他处理。与面粉品质和烘烤品质相比,拔节期和开花期SRWC对面团品质的调控效果明显。其中,面团形成时间和稳定时间在拔节期SRWC 65%和70%条件下随开花期SRWC的提高而降低;开花期SRWC相同时,拔节期SRWC 65%处理较SRWC 70%和75%处理提高了面团形成时间、稳定时间、沉降值、面包体积。综合以上结果,J65A65处理提高了籽粒谷蛋白和谷醇比,延长了面团形成时间和稳定时间,增加了面包体积,有利于改善冬小麦加工品质,是最佳的优质节水测墒补灌方案。

Soil moisture influences nitrogen utilization,protein components and processing quality of winter wheat.However,irrigation time or amount affects soil moisture,so that reasonable irrigation pattern could be conducive to improve resource utilization and grain quality of wheat.The field experiment was carried out to investigate the effects of soil water at jointing （J） and anthesis （A） stage of winter wheat on nitrogen accumulation and grain quality with a high yielding cultivar Wanmai 38 as materials,using supplemental irrigation based on measuring soil water content,during 2010-2011 wheat growth season.Soil water content was controlled by a new strategy that supplemental irrigation based on measuring soil moisture.The soil relative water content （SRWC） in 0-40 cm soil layer was set to 65%,70%,75% at jointing stage,and 65%,70% at anthesis stage,respectively,the treatments were briefed as J65A65,J65A70,J70A65,J70A70,J75A65,J75A70,with the no irrigation treatment as the control.The results showed that nitrogen accumulation amount in different organs at anthesis stage,grain nitrogen amount and total nitrogen amount at maturity increased with the enhancement of SRWC at jointing stage.There was no significant difference on nitrogen accumulation at maturity in J70A70,J75A65 and J75A70,but they were higher than the other treatments,with higher nitrogen harvest index.Under the same SRWC at anthesis stage,higher storage protein content and ratio of gutelin to prolamin was observed in SRWC 70% than in 65% at jointing,while soluble protein content was lower.The glutelin content,ratio of gutelin to prolamin and proportion of storage protein in J65A65 were significantly higher than those in other treatments.Meanwhile,the effect of SRWC at jointing and anthesis stage on dough quality was more obvious than on flour quality and baking quality.Under SRWC at jointing was 65% and 70%,dough development time and stability time reduced with the increase of SRWC at anthesis,but no notable difference was observed in water absorption,gluten index,sedimentation value,bread volume and bread score.When SRWC at anthesis were the same,the dough stability time,sedimentation value and bread volume was higher in treatments SRWC 65% at jointing than those in treatments SRWC as 70% and 75%.To summarize,the treatment J65A65 increased glutelin content and ratio of gutelin to prolamin,extended dough development and stability time,and increased bread volume,so it was an effective SRWC pattern that was beneficial to improve grain quality of winter wheat.