【摘要】 为利用玉米遗传潜力,节约磷矿资源,采用土壤盆栽和根袋相结合的方法,研究了高磷和低磷水平下2杂交玉米幼苗生长、根系形态、根际和非根际土壤的生理特性和微生物数量变化。结果表明:与高磷相比,低磷降低2玉米的株高、总绿叶面积、地上部干重和磷含量、根干重和磷含量,增加了根冠比,降低土壤pH值,促进土壤磷酸酶活性,减少细菌数量和速效磷含量。与非根际土比,根际土的pH、磷酸酶活性和速效磷含量均降低,细菌和放线菌数量均增加,与供磷水平无关。玉米的生物量和磷含量均与根长、根表面积、根际土的pH、细菌数量间呈显著正相关,而与根干重无关,说明根系形态、土壤pH、细菌数量是影响土壤磷素转化和高效吸收的重要因素。与‘冀单28’比,‘蠡玉16’具有优势株高、总绿叶面积、植株干重和磷含量,较大的根长、根表面积、根冠比和较多的细菌数量是该品种高效吸收磷的重要生理机制。更多还原

【Abstract】 To make the most of plant genetic potential and save phosphorus(P)mineral resources,the effects of high and low P levels on plant growth,root morphology,soil physiological characters in rhziosphere and non-rhziosphere and numbers of microorganisms were studied under conditions of pot culture with root-bag.Two maize(Zea mays L.) hybrids,’Liyu 16’ and ’Jidan 28’,were used as the testing materials.The results showed that compared with the high-P level,the height,total green leaf areas,shoot and root dry weight of two maize in low P level were reduced,while the ratio of root to shoot in dry weight increased.Moreover,soil pH was reduced,the phosphatase activity increased,numbers of bacteria and available P content lessened.Compared with non-rhziosphere,pH,phosphatase activity and available P content in rhziosphere were reduced while numbers of bacteria and actinomycete increased,but not related with P levels.Plant biomass and P content were positively related with root length,root surface area and bacteria number,but had no correlation with dry weight of root.Therefore,root morphology,pH and bacteria number in rhziosphere were the main factors affecting plant growth.Compared with ’Jidan28’ cultivar,’Liyu 16’ had higher height,total green leaf areas,dry weight and P content.Larger root length,root surface area,ratio of root to shoot,and more bacteria number may be the primary physiological mechanism leading ’Liyu16’ to possess the capacity of higher-efficient-uptake-P.更多还原