施氮处理对水稻子代乳苗素质的影响

Effects of Various Nitrogen Applications on the Quality of the Progeny Seedlings in Rice

为了探讨N对水稻种子蛋白质含量以及子代乳苗素质的影响 ,在分蘖期和孕穗期对籼稻和粳稻进行不同的施N处理 ,以收获的种子为材料 ,进行水培 ,在萌发后 5～ 13d内测定各处理对乳苗生理活性的影响。结果是 :(1)颖果中蛋白质含量以孕穗期施高N的为最高 ,分蘖期施高N的次之 ,不施N的最低 ;(2 )子代乳苗株高、鲜干重、叶片叶绿素含量、光合速率、可溶性蛋白、IAA含量、胚乳细胞淀粉酶的活性、叶片CAT和根尖的SOD活性、抗寒能力的大小都是孕穗期施高N为最高 ,分蘖期施高N的次之 ,不施N的最低 ;(3)乳苗叶片可溶性糖则是不施N的最高 ,分蘖期施高N的次之 ,孕穗期施高N的最低。因此在水稻生长的后期适当增施N量 ,既能提高种子的蛋白质含量 ,还能促进子代秧苗的生长。

To explore the effects of nitrogen application on the protein content of rice seeds and the quality of its progeny seedlings, water culture was carried out and the physiological activities of the progeny seedlings in 5—13 days after the germination of the harvested seeds of the two common rice cultivars (japonica and indica) were measured. The rice plant was treated with various nitrogen applications at booting and tillering stages respectively. The principal results are as follows: (1) The protein content in caryopsis was the highest in the treatment with the higher application of nitrogen at booting stage than that at the tillering stage. (2)The increment of nitrogen application at booting stage had the positive effects on the height, fresh and dry weight of the seedlings, the chlorophyll content of the leaves, the photosynthetic rate, the content of soluble protein, the IAA content, amylase activities of the endosperm, the activities of CAT in leaves, and SOD in root tips. Meanwhile, their chilling resistance was enhanced compared with the seedlings without nitrogen supply. (3) The soluble sugar content was the highest in the seedlings with no nitrogen application, and the lowest in those with higher application of nitrogen at booting stage. So, the proper increase of nitrogen application at booting stage could be favorable to the growth of rice seedlings as well as the protein content in caryopsis.