【作者】 范小威； 沈宏； 杨存义； 严小龙；

【Author】 FAN Xiao-wei, SHEN Hong, YANG Cun-yi,YAN Xiao-long (Lab of Plant Nutritional Genetics and Root Biology Center, South China Agricultural University, Guangzhou 510642,China)

【机构】 华南农业大学植物营养遗传与根系生物学研究中心；

【摘要】 土壤有效磷含量低是影响酸性红壤上作物生产的重要限制因素之一,如何提高根系对难溶性磷的吸收利用能力一直是土壤与植物营养工作者感兴趣的地方。本文探讨了不同磷效率大豆品种根系细胞壁和根分泌物对难溶性铝磷的活化与吸收能力。结果表明,砂培条件下,磷高效品种(巴西10号)对难溶性铝磷的吸收显著高于磷低效品种(本地2号)。铝磷处理条件下,根系总表面积巴西10号是本地2号的131%,而钾磷处理二者没有明显差异。根系细胞壁对铝磷的活化表明,大豆苗期根系细胞壁对铝磷的活化量显著高于成熟期。苗期、成熟期巴西10号对铝磷的活化量为本地2号的119%、176%。不同栽培方式根系细胞壁对铝磷的活化量表现为水培大于砂培,水培条件下两大豆基因型对铝磷的活化量没有差异。不同生育时期、栽培方式根分泌物对铝磷的活化量表现为,成熟期大干苗期,砂培大于水培。巴西10号根分泌物对铝磷的活化量比本地2号分别高出:69.3%(成熟期)和40.1%(砂培)。上述结果研究表明,大豆根分泌物和根细胞壁对难溶性铝磷的溶解具有促进作用,有利于大豆对铝磷的吸收。更多还原

【Abstract】 Low P availability are one of the major limitation to crop production. How to improve P efficiency are the issues that scientific researchers in the field of soil science and plant nutrition are interested in. In this study, mobilization of aluminum-bound phosphate (Al,P) was examined by root cell wall and root exudates of two soybean genotypes with different P efficiency. Results with sand culture indicated that Brazil 10 had a higher Al,P uptake than Local 2 did. Total root surface area of Brazil 10 was 131 % of that in Local 2 under AI,P treatment, while no difference under KP treatment. Mobilization of Al,P by root cell wall in the seedling stage was significantly higher than that in mature stage. Al,P Mobilized by cell wall of Brazil at seedling and mature stages were 119 % and 176 % of that of Local 2 respectively. The corresponding value under different cultivations was bigger in solution culture than in sand culture. However, no difference with solution culture in Al,P mobilization of two cultivars were observed. Al,P mobilized by root exudates under different stages and cultivations were bigger in mature stage than seedling stage, and were bigger with sand culture than with solution culture. Al,Pmobilized by root exudates were 69.3 % (mature stage) and 40.1 % (sand culture) in Brazil 10 than in Local 2. The above results indicated that root exudates and cell wall of soybean seedlings play an important role in enhancing the mobilization of sparingly soluble phosphates, thus contribute P uptake.更多还原