不同磷效率玉米自交系根系形态与根际特征的差异

Root configuration and rhizosphere characteristics of different maize inbred lines with contrasting P efficiency

通过三室根袋栽培试验,对3种磷高效型和3种磷低效型的玉米自交系在2种不同磷水平下的植株生物量、吸磷量、根系形态、根际pH值以及根际磷酸酶进行研究,比较不同磷利用率基因型玉米自交系的根系形态及根际特征的差异。结果表明,在低磷情况下,磷利用率高的玉米自交系其植株生物量中的根干重、植株的吸磷量、根系形态中的根尖数与根长以及根际磷酸酶的活性方面均高于磷利用率低的玉米自交系。植株的根部干重:磷高效的1号品种(hp1)显著高于磷低效的2号品种(lp2),hp2显著高于lpl、lp2、lp3;hp1、hp2的地上部与根系的吸磷量均显著高于lp2、lp3。hp1、hp2根尖数、根长显著高于磷低效型的lp2、lp3。hp1、hp2、hp3根际土壤的酸性磷酸酶活性显著高于lp2、lp3。其他指标如植株地上部分干重、pH值,磷高效型玉米自交系也存在一定优势。所有品种中hp2与lp3的差异最为显著。

Root configuration and rhizosphere characteristics of the different efficiency-phosphorus maize inbred line types were studied by using a three-chamber-root-bag culture experiment. Three high-efficient-phosphorus maize inbred lines and three low efficiency-phosphorus maize inbred lines were selected for the study. Crop biomass, phosphorus absorption amount, root configuration, rhizosphere pH and phosphatase activity under two P levels were investigated as well. Results showed that under the low P level, root weight, phosphorus absorption amount, number of root tips, root length and rhizosphere phosphatase activity were high for the high-efficient-phosphorus maize inbred lines, and low for the low-efficient-phosphorus maize inbred lines. Root weight of the high-efficient-phosphorus maize inbred line 1 （hpl） was significantly higher than that of the low-efficient-phosphorus maize inbred line 2 （lp2）, while root weight of hp2 was higher than that of lpl, lp2 and lp3, respectively. Phosphorus absorption amounts of shoots and roots of hpl and hp2 were higher than those of lp2 and lp3. Number of root tips and lengths of hpl and hp2 were both higher than those of lp2 and lp3. Rhizosphere acid phosphatase activities of hpl, hp2 and hp3 were higher than those of lp2 and lp3. There was certain superiority in high-efficient-phosphorus maize inbred lines too, such as dry weight of shoot and pH. Among all euhivars, the differences between hp2 and lp3 were the most significant ones.