与温带骨干系相比,P群自交系苗期叶色、叶鞘特征特性明显,株型缺乏紧凑类型,生育期偏晚,单株产量低,抗性强,子粒百粒重和容重较高。P群自交系的光敏感反应主要表现在与营养生长相关的几个性状上,如株高、穗位和雄穗分枝数等。在生殖生长性状上光敏感反应比较迟钝。在温带玉米区适应性较好。但是一些P群自交系如沈137、齐319、1127等各项指标光周期敏感仍反应强烈。 Compared with the temperate skeletons, the leaf color and leaf sheath characteristics of P group inbred lines were obvious at seedling stage, the plant types lacked compact type, the late growth period, low yield per plant, strong resistance, high kernel weight and high bulk density . The photosynthetic reaction of inbred lines in P group mainly manifested in several traits associated with vegetative growth, such as plant height, ear position and branch number of tassel. Photosensitive responses in reproductive growth traits are slow. Adaptability in temperate maize area is better. However, some P-line inbred lines such as Shen 137, Qi 319,1127 and other indicators are still sensitive to photoperiod.