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不同大豆基因型对难溶性磷的吸收研究
UPTAKE OF SPARINGLY SOLUBLE PHOSPHATES BY SOYBEAN ROOTS OF DIFFERENT GENOTYPES
【Author】 Lai Huai Yu Zhi-wei Shen Chun-peng Shen Hong (Laboratory of Root Layer Control,College of Resources and Environment,South China Agricultural University,Guangzhou 510642)
【机构】 华南农业大学资源与环境学院根层调控实验室;
【摘要】 华南地区水热资源丰富,种植大豆(Glycine max L.)有着巨大的生产潜力。然而华南地区土壤有效磷含量低,极大限制了作物生产。因此,研究大豆根系对难溶性磷的活化与吸收,对发展大豆生产具有重要意义。本试验研究了5种大豆基因型对难溶性磷(Ca-P、Al-P、Fe-P)的吸收,发现粤春03-3和粤春03-5的生物量和磷吸收量最高;柳豆1号与巴西10号次之;本地2号最低。不同磷源处理时,大豆生物量和磷吸收量大小顺序为Ca-P、K-P>Al-P>Fe-P>CK。为探讨粤春03-3与本地2号对难溶性磷的吸收机理,研究了难溶性磷在缺磷营养液中的释放规律,发现Ca-P处理时,营养液中磷浓度先逐渐上升,到第8天时达到最大值,而后保持平稳。Al-P、Fe-P处理时,营养液中磷浓度逐渐下降,到第10天时达到最低值。粤春03-3培养液的磷浓度低于本地2号,表明粤春03-3比本地2号具有较强的磷吸收能力。正常生长条件下,两大豆基因型均能分泌少量的柠檬酸,铝处理显著增加柠檬酸的分泌,粤春03-3的柠檬酸分泌量比本地2号高出27%。铝鳌合物质是对Al3+有强螯合能力的化合物,测定分泌物中铝螯合物质发现,粤春03-3分泌的铝螯合物质多于本地2号。上述结果表明,粤春03-3对难溶性磷较强的吸收能力与其较多的柠檬酸和铝螯合物质分泌有关。
【Abstract】 Due to abundant rain and heat resources,South China has a great potential to develop soybean production.However,low phosphate(P) availability is a major limitation to soybean production.In this study,5 soybean genotypes were selected to investigate their ability to absorb sparingly soluble phosphates(Ca-P,Al-P, and Fe-P).Genotypic differences of biomass and P uptake were observed in response to treatments with sparingly soluble phosphates.Biomass and P uptake in Yuechun 03-3(YC03-3) and Yuechun 03-5(YC03-5) were the highest,the second in Liudou 2 and Baxi 10,and the lowest in Bendi 2.The size of biomass and P uptake under different treatments was Ca-P、K-P>Al-P>Fe-P>CK.To explore the different mechanisms of P uptake between YC03-3 and Bendi 2,P release from Ca-P,Fe-P,and Al-P was measured in P-deficient nutrient solution with soybean seedlings.It was observed that P concentration under Ca-P treatment increased gradually,reached the maximum after 8-d treatment,and then became stable.While under Al-P or Fe-P treatment,P concentration decreased gradually and reached the minimum after 10-d treatment.Interestingly,P concentration in the incubation solution with YC03-3 was lower than that with Bendi 2,suggesting that YC03-3 had a stronger ability to absorb P from sparingly soluble phosphates than Bendi 2 did.Organic acid analysis in root exudates indicated that both YC03-3 and Bendi 2 could exude a few amount of citrate under normal growth conditions.Al treatment increased the secretion of citrate greatly.Secretion of citrate from the roots of YC03-3 was 27%higher than that of Bendi 2.Al-chelating substance had a strong ability to chelate Al3+.YC03-3 exuded more Al-chelating substances than Bendi 2.The above results suggested that the stronger ability to utilize sparingly soluble phosphate in YC03-3 rather than in Bendi 2 was probably associated with its more secreted organic acid and Al-chelating substances in the former.
【Key words】 Soybean; sparingly soluble phosphates; uptake; citrate; Al-chelating substances;
- 【会议录名称】 土壤资源持续利用和生态环境安全——中国土壤学会第十一届二次理事扩大会议暨学术会议论文集
- 【会议名称】土壤资源持续利用和生态环境安全——中国土壤学会第十一届二次理事扩大会议暨学术会议
- 【会议时间】2009-11-01
- 【会议地点】中国广东广州
- 【分类号】S565.1
- 【主办单位】中国土壤学会