研究表明 ,郑单 14的最适播种密度为 35 0 0～ 4 0 0 0株 / 6 6 7m2 ;理想播期为 5月 2 5日至 6月 5日 ,不宜在 6月 10日以后播种。其表现高产、稳产的主要生理原因是 :(1)其叶面积指数变化合理 ,叶片持绿时间长、衰老慢 ,叶绿体中的光合色素、蛋白质和可溶性糖含量高 ;(2 )过氧化物酶活性高、丙二醛积累少 ,光合效率高 ;(3)籽粒体积大 ,灌浆时间长 ,千粒重高。 The results showed that the optimum sowing density of Zhengdan 14 was 35 0 0 ~ 40 000/6 6 7 m 2. The ideal sowing date was from May 25 to June 5, and should not be sown after June 10. The main physiological reasons for its high yield and stable yield are as follows: (1) The change of leaf area index is reasonable, the leaves are green for a long time, the senescence is slow, and the content of photosynthetic pigments, protein and soluble sugar in chloroplasts is high; (2) Peroxidase High activity, less accumulation of malondialdehyde, photosynthetic efficiency; (3) large volume of grain, filling a long time, one thousand grain weight.