不同磷效率小麦对低铁胁迫的基因型差异

用营养液培养方法研究了不同磷效率小麦幼苗对低铁胁迫的基因型差异。结果表明,低铁胁迫(-Fe)对磷高效基因型小麦生长的抑制作用显著大于对磷低效基因型。低铁处理下,磷高效基因型81(85)-5-3-3-3、Xiaoyan54和Taihe-5025的植株地上部干重平均比正常供铁(+Fe)处理下降55.2%;磷低效基因型Jinghe90-Jian-17、NC37和Jing41平均33.0%。低铁胁迫显著降低了磷高效基因型小麦的叶片叶绿素含量,3个磷高效基因型的叶绿素a、叶绿素b和叶绿素a+b含量分别降低了35.6%、35.3%和35.3%,磷低效基因型分别降低了16.8%、7.7%和11.9%。低铁胁迫对小麦的根系生长、根系吸磷量和磷利用效率均未产生明显的影响,但显著降低了磷高效基因型小麦的植株地上部吸磷量和根效率比。与正常供铁的处理相比,磷高效和磷低效基因型小麦的地上部吸磷量和根效率比在低铁处理中平均降低了55.0%、54.9%和32.5%、36.4%。磷高效基因型小麦植株体内积累的磷量明显高于磷低效基因型,这是磷高效基因型不耐低铁的主要原因。磷效率越高,对低铁的反应越敏感。

Genotypic difference in response to Fe deficiency of winter wheat with different phosphorus efficiency

The genotypic differences in response to iron deficiency (-Fe) of winter wheat with different phosphorus efficiency were investigated in nutrient solution under controlled conditions. The genotypic differences existed in response to Fe deficiency, which decreased the shoot growth in P efficiency genotypes more significantly than in P inefficiency genotypes. Compared with supplying Fe treatment(+Fe), in -Fe treatment, the average biomass in shoot of three P efficiency genotypes, 81(85)-5-3-3-3、Xiaoyan54 and Taihe-5025 decreased by 55.2%, and that in three P inefficiency genotypes, Jinghe90-Jian-17、NC37 and Jing411 decreased by 33.0%. The different response to Fe deficiency also existed in chlorophyll content between P efficiency genotypes and P inefficiency genotypes. The average contents of three P efficiency genotypes in chlorophyll a、chlorophyll b and chlorophyll a+b decreased by 35.6%, 35.3% and 35.3%, respectively, more significantly than that in three P inefficiency ones by 16.8%, 7.7% and 11.9%. respectively.The Fe deficiency was not significant effect on root growth, P uptake in root and P utilization efficiency (dry matter production per unit of P uptake, g/mg), but decreased the root efficiency ratio (ratio of P uptake in shoot to dry matter, mg/g) and P uptake in shoot in P efficiency genotypes more significantly than in P inefficiency genotypes. The root efficiency ratio and P uptake in shoot in P efficiency genotypes and in P inefficiency genotypes decreased by 55.0%, 54.9% and 32.5%, 36.4% in Fe deficiency treatment respectively. The P accumulation in P efficiency genotypes is much more than that in P inefficiency which appears to be the causative factor of the P efficiency genotypes more sensitivity to Fe deficiency.