中文摘要：

以不同抗冷型玉米品种丰单3（抗冷型）和郑单958（非抗冷型）为试验材料,在黑龙江省Ⅰ、Ⅱ、Ⅲ积温带进行大田试验,研究了不同积温对不同抗冷型春玉米灌浆期叶片光合性能的影响.结果表明：在3个积温带,丰单3和郑单958抽雄开花期和成熟期按Ⅰ、Ⅱ、Ⅲ积温带顺序依次延长,籽粒容重依次降低;丰单3和郑单958叶片的RuBP羧化酶、PEP羧化酶活性对温度的敏感性不同,其中,丰单3灌浆前期（开花后0～20d）两种酶活性高,在温度限制区可正常成熟;郑单958灌浆前期和后期（开花后0～10d、40～60d）两种酶活性高,中期（开花后10～40d）对活动积温不敏感,在温度限制区不能正常成熟.两类玉米叶片的光合速率均与开花后0～10d和30～40d的活动积温呈显著正相关.3个积温带积温在灌浆初期和后期对春玉米光合性能影响显著,同一品种灌浆期活动积温越高,籽粒产量越高;郑单958产量均高于丰单3.

英文摘要：

Taking cold-resistant maize variety Fengdan 3 and cold-sensitive maize variety Zhengdan 958 as test materials, field experiments were conducted in Ⅰ, Ⅱ, and Ⅲ accumulated temperature zones in Heilongjiang Province of Northeast China to study the effects of different accumulated temperature on the photosynthetic performances of different types of cold-resistant spring maize varieties during their grain-filling period. In the three accumulated temperature zones, the tasseling and maturing periods of Fengdan 3 and Zhengdan 958 were prolonged in the order of Ⅰ Ⅱ and Ⅲ, and the grain bulk density decreased in the same order. The RuBPCase and PEPCase activities of Fengdan 3 and Zhengdan 958 leaves had different temperature sensitivity. For Fengdan 3, its leaf RuBPCase and PEPCase activities were high in early grain filling period （0-20 days after anthesis）, and the variety could ripen in temperature-limited region. For Zhengdan 958, its leaf RuBPCase and PEPCase activities were high within 0-10 days and 40-60 days after anthesis but not sensitive to the active accumulated temperature during 10-40 days after anthesis, and the variety could not ripen in temperature-limited region. The photosynthetic rates of the two varieties were significantly positively correlated with the active accumulated temperature during 0-10 days and 30-40 days after anthesis. The effects of the accumulated temperature in the three zones on the photosynthetic performances were significant at both early and later grain filling stages. For the same varieties, the higher the active accumulated temperature in grain filling period, the higher the grain yield. Zhengdan 958 had higher yield than Fengdan 3.