摘要
在低氮(中度缺乏)和高N(丰足)条件下,地上部干物质生长量和稻谷产量在供试品种间的差异顺序为:汕优64>汕优6号>浙丽1号>秀水48,其中杂交稻与常规稻的差异最大,低N条件下的差异又比高N条件下的明显。结果还表明在低N条件下产量较高的品种吸收利用土壤中N素能力较强,其相关的生物学和生理学特征为:1.根系发达,根系生长量、分布密度以及根对NH_4^+的亲和力均较大;2.地上部干物质生产量和功能叶氮、碳同化代谢关键酶,即硝酸还原酶,各氨酸合酶,RuBP羧化酶的活力均较高。此外RuBP羧化酶活力以及其水平受氮素的提高效应也N-高效品种较明显。这些特性均可以作为筛选和鉴别N-高效作物基因型的生理生化指标。
Field and sand culture experiments were conducted to study varietal difference of rice plants in response to N levels and its physiological mechanisms. The results obtained show that at low N (mediately deficiency) and high N (sufficient) levels the biomass of the top and grain yield of the varieties tested at main growth stages decreased in the order: Shanyou 64>Shanyou 6>Zheli 1>Xiushui 48. The greatest difference was found between the hybrids and the conventional varieties, especially at a low N level. The results also show that the rice variety which could obtain higher yield at a low N rate had a greater potential of absorbing and utilizing N from the soil with following characteristics: 1) a well developed and vital root system with a greater root volume and distribution density, and a higher affinity to NH^+_4, i. e. with a smaller K_m value; 2) greater activities of the key enzymes involved in the assimilation of NO^-_2 and NH_3 and photosynthesis in the leaves. All these physiological characteristics may be used as the indices for identifying and selecting N-efficient variety or genotype.
出处
《土壤学报》
CAS
CSCD
北大核心
1992年第1期73-79,共7页
Acta Pedologica Sinica
关键词
水稻
品种
氮素
营养
N nutrition, Michalis-Mentern constant, Root mophology, Glutamate synthase, RuBP cerboxylase, Rice varity
