玉米自交系苗期磷营养特性评价

利用一元线性回归模型对9种基因型玉米自交系在6叶龄苗期的磷(P)营养特性进行了评价。以幼苗的全株或地上部生物量(mg/plant)分别与培养介质对其供磷量(P.mg)建立线性模型,其回归系数作为全株或地上部磷效率的指标;以幼苗的全株或地上部生物量分别与相应的全株或地上部磷含量(P.mg/plant)建立线性模型,其回归系数作为全株或地上部磷利用效率的指标;以幼苗全株磷含量与培养介质对其供磷量建立线性模型的回归系数作为幼苗磷吸收效率的指标。结果表明,9种玉米基因型的磷效率,磷利用效率和磷吸收效率的平均值分别为53.95(全株)和42.61(地上部)、131.84(全株)和124.45(地上部)、0.41。自交系04419的磷效率比平均值约高出45%(全株)和59%(地上部),属于磷效率高效型;而自交系04065和04088的磷效率分别比平均值约低43%、38%(全株)和55%、51%(地上部),属于磷效率低效型;其余自交系的磷效率介于两者之间,为磷效率中间型。玉米自交系苗期的磷效率与磷吸收效率呈显著正相关,与磷利用效率关系不明显;磷吸收效率可作为苗期磷效率预筛选的生理指标。

Evaluation of the phosphorus nutrient characteristics of maize inbred lines at the seedling stage

Phosphorus(P) nutrient characteristics of 9 maize inbred lines at their six-leaf-aged seedling stage were evaluated using linear modeling.Basing on the biomass production of the whole plant or the shoot(mg/plant) vs the P content in culture media contributing to per-seedling(P mg),the linear models were established and their regression coefficients were taken as indices of the P efficiency of the whole-plant or the shoot part.Basing on the biomass production of the whole plant or the shoot part vs the corresponding P content of the whole plant or the shoot part(P(mg/plant)),the linear models were established and their regression coefficients were taken as indices of the P utilization efficiency of the whole-plant or the shoot part.Similarly,basing on P contents in the whole plant vs P content in culture media contributing to per-seedling,the linear models were established and their regression coefficients were taken as indices of P uptake efficiency.The mean values of P efficiency,P utilization efficiency and P uptake efficiency of the above 9 maize inbred lines were 53.95(whole plant) and 42.61(shoot);131.84(whole plant) and 124.45(shoot);0.41,respectively.The highest P efficiency was observed from the inbred line 04419 with respectively 45%(whole plant) and 59%(shoot) higher than the corresponding mean value.The lowest P efficiency was observed from the inbred line 04065 and line 04088 with respectively 43%,38%(whole plant) and 55%,51%(shoot) lower than the corresponding mean value.The other efficiencies were middle.There was a significant correlation between P efficiency and P uptake efficiency at seeding stage of maize inbred lines,indicating that the P uptake efficiency may be employed as a pre-selection criterion for high-P efficiency maize lines at the seedling stage.