两种穗型冬小麦籽粒淀粉积累动态及其有关酶活性变化

花后25d内，大穗型品种豫麦66籽粒中淀粉积累比多穗型品种豫麦49慢，但花后25d后情况则相反。2个品种籽粒中淀粉积累速率的变化均呈单峰曲线，豫麦49峰值出现在花后15～20d，而豫麦66峰值则出现在花后20～25d。灌浆期豫麦66和豫麦49籽粒中蔗糖合成酶(SS)活性变化呈单峰曲线，峰值分别出现在花后20d和15d，整个灌浆期内豫麦66籽粒中SS活性高于豫麦49；2个品种籽粒中腺苷二磷酸葡萄糖焦磷酸化酶(AGPP)和淀粉分支酶(SBE)活性变化均呈单峰曲线，峰值出现在花后20d，而可溶性淀粉合成酶(SSS)活性变化则呈双峰曲线，峰值分别出现在花后10d和20d，且第二个峰值显著高于第一个。相关分析表明，SS、AGPP、SSS和SBE是影响小麦籽粒淀粉积累的关键酶。

Study on dynamic changes of starch accumulation in grain and related enzymes in winter wheat cultivars with two spike types

Two winter wheat cultivars with large-spike type Yumai 66 and small-spike type Yumai 49 were used to study their activities of enzymes associated with starch synthesis in kernel during grain filling stage.The main results indicated that starch accumulated faster in kernel of Yumai 66 than that of Yumai 49 before 25 d after anthesis,but it had an opposite trend after 25 d after anthesis.Starch accumulating rate of two cultivars all had a single-peak curve,the peak of Yumai 49 appeared in 15~20 d after anthesis,but that of Yumai 66 appeared in 20~25 d after anthesis.Changes of SS activity all came to be a single-peak curve,the peak appeared in 20 d and 15 d after anthesis,respectively.The SS activity of Yumai 66 was higher than that of Yumai 49 in the whole grain filling stage.Changes of AGPP and SBE activity in kernel of two cultivars all had a single-peak curve,the peak all appeared in 20 d after anthesis,but SSS activity showed a double-peak curve,its peaks appeared in 10 d and 20 d after anthesis,and the second peak was much higher than that of the first.Correlation analysis indicated that SS,AGPP,SSS and SBE were key enzymes to synthetise starch of winter wheat.