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在植物生长的各个阶段中,对养分的要求受许多因素的影响。由于农业的强化,对这方面知识的需要就更为迫切。本研究的目的,是测定P、Ca和Mg不同浓度对水稻(Oryza sativa L)生长的影响,以及了解这些离子被水稻吸收的情况。将秧苗培植在这些元素配制的营养液中维持其最好生长,P、Ca、Mg的最低浓度分别为25、250及33μM。当P的浓度较高时,可以得到一条对应于稻株组织含P量的线性吸收曲线。生长100天的植株,其地上部组织里P的临界浓度为0.4％。在生长25天到125天的植株体内,维持最好生长的Ca的含量变化为242到2,373μg—原子/5株。为了获得最好的生长,Ca的相 应的吸收范围(IM)应为14～320μg—原子/每天每克根干重。生长25、50、75、100和125天的植株,每小时每克鲜重根吸收的Mg应分别为13.7、7.7、4.3、4.0和2.4μg才能维持最好的生长。随着生育时期的进展,植株体内P和Ca的含量及其利用效率有所增加,但其相应生长率以及Ca和Mg的吸收速率则有所下降。
At various stages of plant growth, nutrient requirements are influenced by many factors. Due to the intensification of agriculture, the need for knowledge in this area is even more pressing. The purpose of this study was to determine the effects of different concentrations of P, Ca and Mg on the growth of Oryza sativa L and to understand the absorption of these ions by rice. The seedlings were cultivated in the nutrient solution formulated with these elements to maintain their best growth. The minimum concentrations of P, Ca and Mg were 25, 250 and 33 μM, respectively. When the concentration of P is higher, a linear absorption curve corresponding to the content of P in the rice plant tissue can be obtained. Plants grown for 100 days had a critical concentration of P in shoot tissue of 0.4%. In plants grown from 25 days to 125 days, the content of Ca that maintained the best growth varied from 242 to 2,373 μg-atom / 5 strains. In order to obtain the best growth, the corresponding absorption range (IM) of Ca should be 14 to 320 μg-atom / g dry weight per day. Plantlets grown at 25, 50, 75, 100 and 125 days should absorb 13.7, 7.7, 4.3, 4.0 and 2.4 μg Mg per gram fresh weight per hour, respectively, in order to maintain optimal growth. With the progress of growth period, the content and utilization efficiency of P and Ca in plants increased, but the corresponding growth rate and the absorption rate of Ca and Mg decreased.