施氮量对两个粒型小麦品种籽粒胚乳细胞增殖及糖含量的影响

为了解小麦胚乳细胞增殖、糖代谢在粒型间的差异及氮营养的调控效应,2009-2010年度以大粒型品种郑育麦9987和小粒型品种郑麦004为材料,研究了施氮量对小麦籽粒胚乳细胞增殖、细胞壁转化酶活性及糖含量的影响。结果表明,郑育麦9987胚乳细胞数(11.92×105)较郑麦004(10.73×105)多11.1%。施氮量影响籽粒胚乳细胞数,其中郑育麦9987低氮处理(150kg·hm-2)的胚乳细胞数目较高氮处理(300kg·hm-2)增加29.1%,而郑麦004则表现为高氮处理较低氮处理增加44.7%。两品种籽粒细胞壁转化酶活性均于花后5~8d达到峰值,花后20d则降到较低水平;籽粒可溶性糖和蔗糖含量均随灌浆进程整体呈先上升后下降趋势,在花后25d有一个小波峰。增施氮肥可增加籽粒细胞壁转化酶活性,提高后期籽粒可溶性糖和蔗糖含量。表明增施氮肥有利于小麦籽粒胚乳细胞增殖、光合产物的积累与运转,从而提高了粒重。

Effects of Nitrogen Application on Endosperm Cell Proliferating, Activity of Cell Wall Invertase and Sugar Content in Grains of Wheat Cultivars with Different Grain Size

The effects of different nitrogen application levels on the endosperm cell proliferating, cell wall invertase activity and sugar content in grains of wheat with different kernel weight were investigated. The experiment was carried out at the experimental farm of Henan Agricultural University in 2009-2010 wheat growing season. The results showed that the number of endosperm cells in grains of zhengyumai9987 (11.92×10⁵) was 11.1% higher than that of zhengmai004 (10.73×10⁵). The high nitrogen application treatment increased the number of endosperm cells by 44.7% for the small grain-size wheat cultivar, but decreased it by 29.1% for the large grain-size wheat cultivar. The activity of cell wall invertase in grains increased and reached a peak value at five days after anthesis (5 DAA), then decreased to a lower level at 20 DAA. Both the soluble sugar content and the sucrose sugar content in grains declined after anthesis, but slightly increased to a small peak value at 25 DAA. The activities of cell wall invertase in grains of both wheat cultivars were increased in the high nitrogen application treatment. The soluble sugar content and the sucrose sugar content in grains were slightly improved in the high nitrogen application treatment, which would benefit the kernel weight of winter wheat.