不同穗型冬小麦品种灌浆期旗叶碳氮代谢特点及籽粒淀粉积累动态

C-N Metabolic Characteristics in Flag Leaf and Starch Accumulating Developments in Seed during Grain Filling Stage in Two Winter Wheat Cultivars with Different Spike Type

灌浆期两个不同穗型冬小麦品种 :多穗型品种豫麦 4 9和大穗型品种豫麦 6 6旗叶光合速率、SPS活性和 WSC含量的变化均呈单峰曲线 ,但豫麦 6 6的峰值出现偏晚 ,而且灌浆中后期叶片代谢活性下降缓慢 ,显示出源端较强的同化物持续供应能力。两品种旗叶 NR活性变化趋势基本相同 ,但开花后 5～ 2 0 d内 ,豫麦 4 9旗叶 NR活性高于豫麦 6 6 ,开花后 2 0～ 35 d内情况则相反。籽粒中 IAAO活性变化呈双峰曲线 ,其峰值分别出现在花后 15 d和 30 d,SS活性与淀粉积累速率呈极显著的正相关 (r=0 .76 39* * ) ,在整个灌浆期籽粒的 SS活性变化呈单峰曲线 ,豫麦 6 6的峰值出现较晚 ,但持续时间较长 ,淀粉积累速率呈现同样的趋势。显示出豫麦 6 6后期仍可保持较强的库活性。

Two winter wheat cultivars with large spike type cultivar Yumai 66 and small spike type cultivar Yumai 49, were used to study their C N metabolic characteristics in flag leaf and starch accumulated in kernel during grain filling stage. Changes of photosynthetic rate, SPS activity and WSC content in flag leaf appeared to be a single peak curve, but Yumai 66 reached the peak a little later than that of Yumai 49, and leaf metabolic activity decreased slowly during later filling stage. It showed that “Source” had strong supplying ability of assimilating matter. NR activity of flag leaf in two cultivars had the same trend, but Yumai 49 was superior to Yumai 66 during 5~20d after anthesis, it had an opposite trend during 20 35d after anthesis. Change of IAAO activity in seed came to be a double peak curve, its peak appeared in 15d and 30d after anthesis, respectively. It presented significant positive correlation ( r =0.7639 ** ) between SS activity and starch accumulating rate. Change of SS activity had a single peak curve during the whole filling stage. The peak of Yumai 66 came a little later than that of Yumai 49, but it sustained a long time. Starch accumulating rate had the same trend. It showed that Yumai 66 maintained stronger “sink” activity during the later stage.