不同菜豆基因型根系对难溶性磷的活化吸收

通过溶液培养和砂培试验,研究了不同菜豆基因型根系对难溶性P化合物(Al-P和Fe-P)的活化、吸收及根系分泌的有机酸对难溶性Al-P和Fe-P的活化能力。结果表明,菜豆在Al-P处理中生长要好于Fe-P处理。菜豆在耐低P方面存在着一定的基因型差异。来源于安第斯基因库的大粒种基因型的生物量和吸P量明显大于来源于中美基因库的中、小粒种基因型,其中来源于安第斯基因库的菜豆基因型G19839有较明显的耐低P和适应Fe-P的能力。菜豆根系分泌物对难溶性P有一定的活化能力,P胁迫下菜豆根系分泌物对难溶性Fe-P和Al-P的活化能力都较正常供P时高;菜豆根系分泌物中有柠檬酸、甲酸和乙酸,柠檬酸对难溶性Fe-P和Al-P的活化能力远远高于甲酸和乙酸。

Mobilization and uptake of insoluble phosphorus by different common bean genotyes

Solution culture and sand pot experiments were carried out to study the mobilization and uptake of phosphorus compounds ( K-P, Ca-P, Al-P and Fe-P) by different common bean(Phaseolus vulgaris L.)genotypes as affected by organic acid exudates The results showed that common bean had a significant variation in response to insoluble P compounds Generally, the growth of plant and P uptake by the larger seeded genotypes from the Andean gene pool was better that by middle and small seeded genotypes from the Middle American gene pool The genotype G19839 from the Andean gene pool had better tolerance of low P stress and adaptation to Fe-P. Under low-P stress, root exudates had higher ability to mobilize insoluble Fe-P and Al-P than that at normal P supply The roots secreted citric acid, formic acid and acetic acid, and the citric acid is more effective than formic acid and acetic acid in mobilizing insoluble Fe-P and Al-P, indicating that citric acid may play an important role in mobilizing the insoluble P