Relationship between endosperm cell and activities of key enzymes for starch in maize with different plant types | 不同株型玉米籽粒胚乳细胞与淀粉合成关键酶活性分析

Chinese. 研究不同类型玉米品种籽粒胚乳细胞增殖与籽粒充实期淀粉合成关键酶活性的关系。以紧凑型玉米品种(先玉335和郑单958)和平展型玉米品种(长城799和农大364)为试验材料，于授粉后不同时间取果穗中部籽粒，测定胚乳细胞数、单粒质量、淀粉含量、腺苷二磷酸葡萄糖焦磷酸化酶（ADPG）、尿苷二磷酸葡萄糖焦磷酸化酶（UDPG）活性、可溶性淀粉合成酶(SSS)和束缚态淀粉合成酶(GBSS)活性，研究不同玉米品种籽粒胚乳细胞增殖动态和籽粒淀粉合成关键酶活性的关系。在灌浆中后期，先玉335籽粒淀粉合成关键酶（ADPG、UDPG、SSS和GBSS）活性均高于其他3个玉米品种；先玉335和郑单958籽粒胚乳细胞数、淀粉含量、单粒质量均显著高于长城799和农大364。玉米籽粒胚乳细胞数与单粒质量、淀粉含量和4种淀粉合成关键酶均呈正相关。库容量和库活性是制约玉米籽粒淀粉积累的主要因素。保证籽粒充实期间较高的胚乳细胞增殖速率及淀粉合成关键酶活性是实现玉米高产的关键。

English. The proliferation process of endosperm cell and its relationship with activities of key enzymes for starch were studied. The upright maize varieties Xianyu 335 and Zhengdan 958 and the common maize varieties Changcheng 799 and Nongda 364 were chosen as the experiment material. Central kernels were collected after the pollination stage, endosperm cell number, kernel weight, starch content, activities of key enzymes for starch were determined, and the relationship was analyzed. During the later grain-filling period, key enzymes: (ADPG, UDPG, SSS and GBSS) for starch of Xianyu 335 were higher than other three varieties. And the endosperm cell number, starch content, grain weight of Xianyu 335 and Zhengdan 958 were higher than Changcheng 799 and Nongda 364. The endosperm cell number had significantly positive correlation with grain weight, starch content and the enzyme activities for starch. The results here suggested that grain sink strength and activities were the main factors responsible for starch accumulation in maize. The higher endosperm cell numbers and key enzymes for starch were very important for the high yield of maize.