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

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 (hp1) 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 lp1, lp2 and lp3, respectively. Phosphorus absorption amounts of shoots and roots of hp1 and hp2 were higher than those of lp2 and lp3. Number of root tips and lengths of hp1 and hp2 were both higher than those of lp2 and lp3. Rhizosphere acid phosphatase activities of hp1, 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 cultivars, the differences between hp2 and lp3 were the most significant ones.