两种供水条件下两穗型小麦品种籽粒淀粉积累及相关酶活性的变化特征

Characterization of Starch Accumulation and Activities of Enzymes Involved in Starch Synthesis in Grains of Wheat Cultivars Differing in Spike Types Field-Grown in Irrigation and Rainfed Conditions

在灌溉和旱作2种栽培条件下,研究了大穗型(山农710331和潍麦8号)和多穗型(济南17和鲁麦21)小麦籽粒淀粉积累及相关酶活性的变化特征。结果表明,淀粉积累速率(SAR)和蔗糖合成酶(SS)、ADPG焦磷酸化酶(AGPase)、淀粉合成酶(SSS和GBSS)和淀粉分支酶(SBE)等活性均存在明显的基因型差异。灌溉条件下大穗型品种籽粒淀粉合成相关酶的活性显著高于多穗型品种,旱作栽培条件下两穗型品种间差异变小。旱作栽培宜于增加灌浆前、中期AGPase、SS和SBE的活性,尤其对多穗型品种。大穗型品种在灌浆中后期比多穗型品种具有更强的淀粉合成能力,但对水分较为敏感。用Richards方程模拟籽粒淀粉积累过程表明,大穗型品种籽粒淀粉积累时间长、速率高,是其淀粉积累量高的原因。

The study was carried out to characterize the starch accumulation and activities of some key enzymes in big-spike type cultivars, SN710331 and VM8, and poly-spike type cultivars, LM21 and JN17, under irrigated and rainfed conditions. Results showed that starch accumulation rate （SAR） and activities of SS, AGPase, SSS, GBSS, and SBE in big-spike type eultivars were significantly higher than those in poly-spike type eultivars. The soil water deficit led to the increases at early grain-filling period and decrease during late grain-filling, respectively, in SAR, accumulation duration and activities of the key enzymes above. Water deficit enhanced grain starch accumulation in poly-spike type eultivars. The simulation with Riehards equation showed that starch accumulation duration and SAR determine the starch accumulation amount. The grains of big-spike type eultivars maintained longer filling duration, higher SAR and greater activities of related enzymes than those of poly-spike type eultivars during mid and late grain-falling.