【摘要】 以种植于大田2个不同类型水稻品种为材料,自移栽后10 d至成熟设置常规水层灌溉(CF)和轻干湿交替灌溉(AWMD) 2种灌溉方式,研究AWMD对水稻茎(含叶鞘)中非结构性碳水化合物(NSC)的积累与转运、籽粒灌浆和水分利用效率的影响。结果表明:与CF相比,AWMD处理显著提高水稻茎蘖成穗率、单茎叶面积、叶片光合速率、茎中NSC的积累,显著提高花后茎中NSC往籽粒中运转量、产量和灌溉水利用效率。AWMD可提高茎中蔗糖磷酸合成酶、α-淀粉酶活性和蔗糖转运蛋白基因(OsSUT1)的相对表达水平,以及弱势粒中颗粒结合型淀粉合成酶和可溶性淀粉合成酶活性,进而促进花前储存在茎中的淀粉水解,增加茎中可溶性糖浓度,促进同化物从茎往籽粒运转及弱势粒灌浆。更多还原

【Abstract】 The objective of the study was to elucidate whether and how an alternate wetting and moderate soil drying(AWMD) regime could enhance the accumulation and remobilization of non-structural carbohydrates(NSC) in the stems(including sheaths), and consequently, promote grain filling and increase grain yield and water use efficiency(WUE) of rice. Two rice cultivars were grown in the paddy field, and two irrigation regimes, continuous flooding irrigation(CF) and AWMD were imposed from 10 days after transplanting to maturity. The results showed that, in comparison with the CF regime, the AWMD regime significantly increased the number of productive tillers, leaf area per stem, photosynthetic rate, NSC accumulation in stems, enhanced NSC translocation to the grain during grain filling, and increased grain yield and WUE. The enhanced activities of α-amylase, sucrose phosphate synthase, and rice sucrose transporter(OsSUT1) relative expression level in stems, as well as the increased in the activities of granule bound starch synthase and soluble starch synthase in inferior spikelets, accounted for the faster hydrolysis of starch in stems and the increase in carbon assimilate remobilization and better grain filling under AWMD regime than those under CF regime.更多还原