不同磷效率大豆农艺性状与磷/铁利用率对磷素的响应

Response of agronomic traits and P/Fe utilization efficiency to P application with different P efficiency in soybean

土壤中磷含量与植物铁的吸收密切相关,为研究供铁充足条件下不同P∶Fe配比对不同磷效率基因型大豆农艺性状和磷/铁利用率的影响,本文以前期筛选到的磷高效和磷低效大豆品种为试验材料,采用沙培方式和裂区设计研究不同P∶Fe比对大豆生物学性状的影响及基因型差异,并利用因子得分综合评价磷高效和磷低效基因型对不同P∶Fe处理的响应,以解析农艺性状与大豆体内磷/铁利用率的关系,从而为磷、铁肥合理施用提供理论依据。结果表明:(1)R5期,磷高效基因型在各处理下的株高、茎粗、根干重和地上部干重增长相对较快,且均大于磷低效基因型;磷高效和磷低效基因型在P∶Fe比为100∶100处理下的R5期单株根干重较低,而百粒重较大。此外,磷高效和磷低效基因型的籽粒磷利用率在P∶Fe比为1000∶100时降至最低。(2)典型相关分析表明,磷高效基因型R5期的茎粗与叶片铁利用率呈正相关关系,而磷低效基因型R5期的地上部干重与叶片磷利用率呈负相关关系。(3)R8期单株地上部干重和R3期叶片磷利用率的增加有助于磷高效基因型单株粒重的增加,而R3期单株根重的增加反而会导致磷高效基因型单株粒重的下降。R3期株高、R3期和R8期地上部干重的增加都有助于磷低效基因型单株粒重的增加,而R3期、R5期和R8期的茎粗以及R5期叶片铁利用率的增加反而导致磷低效基因型单株粒重下降。而且,R8期单株地上部干重对磷高效和磷低效基因型的直接正向贡献均最大。(4)利用因子得分综合评价发现,P∶Fe≤100∶100时,磷高效和磷低效基因型在P∶Fe比为100∶100处理下的综合表现最好;当P∶Fe≥500∶100时,磷高效和磷低效基因型在P∶Fe比为1000∶100处理下的综合表现最好。综上,鼓粒初期可以作为筛选不同磷效率基因型的一个重要时期。在铁供应充足情况下,应考虑到土壤磷素累积和植酸对磷素效率影响问题,无论是磷高效还是磷低效基因型施P∶Fe比达到1∶1时整体表现最好。

The phosphorus content in soil is closely related to the iron absorption in plant.In this study,15 agronomic traits were analyzed by principal component analysis in sand culture and split blot design,with P-efficient and P-inefficient soybean varieties screened in the early stage as the experimental materials.To analyze the relationship between agronomic traits and P/Fe utilization efficiency,and to provide the theoretical basis for the rational application of P and Fe fertilizer in soybean,the effects of different P:Fe ratios on biological traits and genotypic differences were studied in response to P-efficient and P-inefficient genotypes under different P:Fe treatments by factor scores in soybean.The results were as follows:(1)At R5 stage,plant height,stem diameter,root dry weight,and shoot dry weight of P-efficient genotypes were increased relatively rapidly under each treatment,and all of them were higher than those of P-inefficient genotypes.When P:Fe ratio was 100:100,root dry weight per plant at R5 stage was lower,while 100-seed weight was higher.In addition,when P:Fe ratio was 100:100,P utilization efficiency of the two soybean genotypes were the lowest.(2)Canonical correlation analysis revealed that stem diameter at R5 stage of P-efficient genotypes was positively correlated with Fe utilization efficiency in leaves,while shoot dry weight of P-inefficient genotypes was negatively correlated with P utilization efficiency in leaves.(3)The increase of P utilization efficiency of leaves at R3 stage and shoot dry weight at R8 stage were beneficial to the increase of seed weight per plant of P-efficient genotypes,while the increase of P-efficient genotypes at R3 stage would lead to the decrease of seed weight per plant of P-efficient genotypes.The increase of plant height at R3 stage,shoot dry weight at R3 and R8 stages contributed to the increase of seed weight per plant of P-inefficient genotypes,while the increase of stem diameter at R3,R5,and R8 stages,and Fe utilization efficiency of leaves at R5 stage resulted in the decrease of seed weight per plant of P-inefficient genotypes.Furthermore,shoot dry weight at R8 stage had the largest direct positive contribution to both P-efficient and P-inefficient genotypes.(4)Comprehensive evaluation by factor score showed that when P:Fe≤100:100,the comprehensive performance of P-efficient genotypes and P-inefficient genotypes were the best when P:Fe ratio was 100:100.When P:Fe≥500:100,the comprehensive performance of P-efficient genotypes and P-inefficient genotypes were the best when P:Fe ratio was 1000:100.In conclusion,the early stage of seed filling can be an important stage for screening soybean genotypes with different P efficiency.P:Fe ratio at 1:1 was better for both P-efficient and P-inefficient genotypes under sufficient Fe supply,considering the accumulation of phosphate fertilizer in soil and effect of phytates in seed on P efficiency.