The Effects of Low Phosphorus Stress on Morphological and Physiological Characteristics of Maize (Zea mays L.) Landraces

A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total leaf area, and plant dry weight, but greatly increased density of root hairs and root top ratio. In addition, P-deficiency induced the significant enhancement of phosphorus utilization efficiency and the amount of proline, malondialdehye (MDA), acid phosphatase (APase), peroxidase (POD) and superoxide dismutase (SOD), but the significant reduction of P uptake and soluable protein content. Since P-deficiency had smaller effects on the P-tolerant maize landraces DP-44, DP-32 and DP-33 as compared with P-sensitive landraces DP-29 and DP-24, it was demonstrated that differences of tolerance to P-deficiency existed among different maize landraces. The results based on the correlation analysis showed that the economic yield of maize landraces had relationships with their morphological and physiological characteristics under P-deficiency.