低磷胁迫下磷高效玉米单交种的形态生理特性

以齐319耐低磷突变体为亲本组配的杂交组合SD-1、SD-2为供试材料,采用溶液培养方法研究了它们对磷的吸收、转运及植株体内磷的利用效率,进而确定在低磷胁迫下其对根系形态学和生理生化机制的适应性反应。结果表明,磷胁迫下(-P)与对照(SD-1-CK、SD-2-CK)相比SD-1、SD-2有较强的磷吸收能力和利用效率;SD-1、SD-2的根系干重、总根长、根总表面积、平均根尖数均明显增加,而平均直径减小;在与磷吸收效率有关的生理指标上,SD-1、SD-2具有更大的根总吸收面积、活跃吸收面积以及在磷吸收动力学上表现出较大的Imax和较低的Km、Cmin。因此认为,SD-1、SD-2对磷具有高的吸收效率是由于根系生长旺盛,根系吸收面积大、根系活力强和对磷亲和力高所致。

Morphological and physiological characteristics of P - efficient maize hybrid to stress of phosphorus deficiency

The genotypic differences in efficiency of absorption,utilization and transportation of phosphors(P) in two maize hybrid combination(SD1、SD-2),and their responses to low P in root structure and their physio-biochemical mechanisms were studied in hydroponics culture in P-deficiency condition.The results showed that compared with SD-1-CK、SD-2-CK,SD-1 and SD-2 had higher P absorption and utilization efficiency.Under low P condition,the root dry weight,length,surface area,and average root number for the two cultivars increased obviously,while the average root diameter decreased.The two combination had larger root total uptake area and active areas,showing longer I_max,but lower K_m and C_min values in the P absorption kinetics.In this experiment,the higher P uptake efficiency of SD-1 and SD-2 depended on more extensive root systems,larger root surface area,stronger root activity and affinity for P nutrition.