接种菌根真菌对不同磷效率基因型大豆生长和磷吸收的影响

Effect of mycorrhizal fungal inoculation on the growth and phosphorus uptake by soybean genotypes with different phosphorus use efficiency

接种丛枝菌根真菌(AMF)能显著促进大豆生长和对磷的吸收,但不同磷效率基因型大豆对AMF接种的响应还少有报道。为探究接种AMF对不同磷效率基因型大豆生长和磷转运基因表达的影响,以磷高效大豆BX10和磷低效大豆BD2为试验材料进行盆栽试验,设置接菌和不接菌处理,对大豆干重、菌根侵染性状、氮磷养分含量、根系性状,以及菌根诱导的磷转运基因表达进行了分析。结果表明,AMF接种显著促进了大豆的磷吸收,并且接菌效果存在显著的基因型差异,接种AMF显著增加了BD2的地上部干重、磷含量以及植株总磷吸收量,但只增加了BX10的地上部磷含量和总磷吸收量,对植株地上部干重没有显著影响。无论接种与否,BD2的地上部磷含量均显著高于BX10,表明磷低效的BD2具有较高的植株体内磷转运能力。不接菌条件下,两个大豆基因型根系性状无显著差异;接种AMF后BX10的根系体积和根系平均直径均显著高于BD2。BD2的菌根生长反应(MGR)和菌根磷反应(MPR)均显著高于BX10,对菌根依赖性更高。此外,在接菌处理的BD2根系,代表菌根途径磷吸收的磷转运基因GmPT8、GmPT9和GmPT10表达均显著高于BX10;相应地,BD2的总磷吸收量也显著高于BX10。以上结果表明,接种AMF对促进磷低效大豆BD2生长和磷吸收的作用更大,这可能主要是由于BD2菌根途径的磷吸收量较高,体内磷转运效率较高。以上结果将为研究AMF接种对磷吸收的贡献提供理论依据。

Inoculation of arbuscular mycorrhizal fungi(AMF)can significantly promote soybean growth and phosphorus(P)uptake.However,information about the growth response of soybean genotypes with different P use efficiency to AMF inoculation is limited.In order to explore the effects of AMF inoculation on the growth and phosphate transporter gene expression in different soybean genotypes,a pot experiment was conducted to analyze plant dry weight,mycorrhizal infection characteristics,nitrogen and P contents,root traits,and mycorrhizal inducible phosphate transporter gene expression using P-efficient soybean BX10 and P-inefficient soybean BD2 under mycorrhizal(AM)and non-mycorrhizal(NM)inoculation treatments.The results showed that AMF inoculation significantly increased P uptake in the two soybean genotypes,and there were significant genotypic differences in mycorrhizal effects.Mycorrhizal inoculation significantly increased the shoot dry weight,P content,and total P uptake in BD2,but only significantly increased shoot P content and total P uptake in BX10.BD2 showed higher shoot P content than BX10 irrespective of the inoculation treatments,indicating that a high content of P was translocated from the roots to shoots in P-inefficient BD2.There was no significant difference in root traits between the two soybean genotypes under the NM treatment.However,BX10 showed higher root volume and average diameter than BD2 in the AM treatments.BD2 presented higher mycorrhizal dependence,mycorrhizal growth response,and mycorrhizal P response than BX10.Additionally,the expression of phosphate transporter genes GmPT8,GmPT9,and GmPT10,which indicate mycorrhizal P uptake pathway,was significantly higher in the mycorrhizal roots of BD2 than those of BX10,and consequently,total P uptake of BD2 was higher than that of BX10.The results indicate that mycorrhizal inoculation has greater effects on the growth and P uptake of BD2 than BX10,which can be attributed to the higher P uptake via the mycorrhizal pathway and higher P translocation efficiency of BD2 plants.The results provide a theoretical basis for studying the contribution of mycorrhizal inoculation to P uptake.