大豆利用难溶磷源基因型差异

来源于不同pH土壤上的各种大豆基因型利用难溶性磷源有明显差异.采用分别代表着南方、西北和东北本地品种三种基因型大豆,研究它们生物量、磷素积累、分泌的有机酸、根际pH和磷素利用效率(PUE)的差异.三种基因型大豆都比较偏爱Al-P,然而,绥农10号和泥巴豆在利用Al-P时,生物量比Na-P分别少8.5%和9.4%,比Ca-P和Fe-P分别多5.3%和11.8%,6.4%和42.2%.新大豆1号利用Al-P时生物量比Na-P、Fe-P和Ca-P分别多1.4%、20.8%和40.8%.地上部、根系和根瘤含磷量变化范围分别在1.37～2.47 mg/g、1.39～3.04 mg/g和3.20～4.73 mg/g.绥农10号、新大豆1号和泥巴豆最大总磷含量分别出现在Al-P、Fe-P和Fe-P条件下.泥巴豆根系分泌的有机酸表现出下面的顺序:草酸＞乳酸＞苹果酸;新大豆1号表现为:乳酸＞苹果酸＞丙二酸＞草酸＞柠檬酸;泥巴豆表现为:苹果酸＞草酸＞乳酸＞柠檬酸＞丙二酸.无论供给哪种形态磷源,根际pH变化范围为5.48～6.52.新大豆1号磷素利用效率比绥农10号和泥巴豆高,绥农10号、新大豆1号和泥巴豆最大磷素利用效率分别出现在Al-P、Al-P和Na-P源条件下.这些结果表明,不同基因型大豆生长和磷吸收对各种难溶磷源的反应不同,各基因型磷素利用差异与根系分泌物和根际pH有关.

Genotypic Variation in P Utilization of Soybean(Glycine max L. )Grown in Various Insoluble P Sources

The information on soybean genotypes originating from different pH soil utilized insoluble P sources was various.Three soybean genotypes representing typical native species were collected from south,western and northeast of China.Plant biomass,P accumulation,organic acid excretion,pH and PUE were analysed.Three genotypes all favoured in Al-P,however,Suinong 10 and Nibadou total biomass in Al-P was 8.5% and 9.4% less than Na-P,respectively,then 5.3% and 11.8%,6.4% and 42.2% more than Ca-P and Fe-P,respectively.For Xin soybean 1 total biomass was 1.4%,20.8% and 40.8% more than Na-P,Fe-P and Ca-P,respectively.P concentration ranged from 1.37 to 2.47 mg/g,1.39 to 3.04 mg/g and 3.20 to 4.73 mg/g in shoots,roots and nodules,respectively.The maximum total P concentration was Al-P,Fe-P and Fe-P in Suinong10,Xin soybean 1 and Nibadou,respectively.Irrespective of genotype,the amount of organic acid exuded followed the order L(-)-malic>Oxalic>L(+)-lactic>Malonic>Succinic>Citric.Howeve-r,for Suinong 10 the order was Oxalic>L(+)-lactic>L(-)-malic,for Xin soybean 1 the order was L(+)-lactic>L(-)-malic > Malonic>Oxalic> Citric and for Nibadou the order was L(-)-malic>Oxalic>L(+)-lactic>Citric>Malonic.Solution pH ranged from 5.48 to 6.52.PUE(phosphorus use efficiency) in Xin soybean 1 was more than Suinong 10 and Nibadou,irrespective of P source.The maximum PUE was Al-P,Al-P and Na-P in Suinong 10,Xin soybean 1 and Nibadou.The results suggest that soybean genotypes differ in growth response and P uptake from insoluble P sources and genotypic variation in P acquisition was related to root exudation and pH.