| Pot experiments and solution culture were undertaken in a greenhouse of GAU in 2002. 4 genotypes spring wheat and 3 genotypes spring faba-bean were chosen as trial materials. The root morphological character, activity of acid phosphatase (Apase), traits of P-uptake and distribution, P-use efficiency (PUE) were measured at different growth stages.The differences of P-uptake and P use efficiency were compared in different genotypes so that index and theoretical basis were provided for selecting genotypes of higher P efficiency and tolerant of P deficiency. The results were as followed:1. The activity of Apase secreted by the roots increased under P-deficiency conditions. Under P-stress soil, activity of root s Apase of GanChun 20 was higher than P-application, between 49.27% and 121.73%, LongChunl6 was higher than P-application, between 25.68% and 44.60%. LC5 was higher than P-application, 25.45%.2. Root morphology characteristics were affected significantly by P application. Under the condition of low P, adaptation of crops to low P stress were to reduce root radius, increase root shoot ratio, raise specific surface area of plant roots, increase root length etc. Different plant species and even genotypes of the same species differed in their ability to grow on soil low in P; in other words, there were some differences of root morphology. DingXi 33 s root length changed obviously, at the average of 36.22%, LongChunl6s root radius and root special area also changed distinguishly, 26.23% and 26.01%, respectively. But in jointing stage of wheat, comparison of P-deficiency with P-supply, the root special area and R/C of LongChun 16 increased by 71.43% and 70.82%, respectively, and the root radius of LongChun 16 decreased by 71.53%.In maturity stage of wheat, the largest of root radius decreasing ,root special area and R/C increasing were GanChun 20, 37.50%,36.15% and 70.82%,respectively, which showed GanChun 20 and LongChun 16 were sensitive more than DingXi 33 and HuiNing 18 to P, and belonged to sensitive type genotypes, and the root length of DingXi 33 increased only significantly, but other root morphology indexs did not increase significantly. In whole growth process of faba-bean, the average fluctuating range of root length, root radius, root special surface area and R/C of LC5 were more obvious, 36.40%, 65.10%, 65.27% and 13.46%, respectively. This showed LC 5 was sensitive to P among genotypes tested, and belonged to sensitive type genotype.3. Among wheat and faba-bean genotypes with different regulation abilities P uptake and P utilization exited large variation. From P concentration in plant in maturity stage, GanChun 20 had the hightest P concentration in all organs, the next one was LongChun 16, which showed GanChun 20 and LongChun 16 had the strong ability of P uptake. From average P-use efficiency in shoot, the ability of P utilization of DingXi 33 and HuiNing 18 were higher than GanChunn 20 and LongChun 16, but P translocated to grain of Ganchun 20 was higher obviously than other genotypes, the root efficiency (RE) of Longchun 16 was higher significantly than other genotypes. Under soil low in P, RE of Ganchun 20 was highest, those showed GanChun 20 expressed the higher RE in late stage.Among P concentration and P use efficiency examined in maturity of faba-bean, P concentration in each organ of LC5 and 8409 were high significantly than 8354, but P use efficiency in shoot of 8354 was high significantly than LC5 and 8409, which showed that LC5 and 8409 belonged to genotypes of higher P uptake efficiency, and 8354 belonged to genotype of higher P translocation efficiency.4. The grain yield was affected obviously by P-levels and heredity factor. P-deficiency in soil caused yield to lower, and the range of decreasing was different in different genotypes. Yield of GanChun 20 and LongChun 16 based on P2 decreased by 36.32% and 24.45%, respectively, and fluctuating rang of Dingxi 33 and Huining 18 was small. Above showed that DingXi 33 and HuiNing 18 belonged to P dull type genotypes, and...
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