Morphological and physiological characteristics of corn (Zea mays L.) roots from cultivars with different yield potentials

Abstract

Improving grain yield per unit area is needed to meet the growing demand for corn in China where the availability of fertile land is very limited. Roots are vital organs for yield improvement. A field experiment was conducted in 2009 and 2010 to compare the Morphological and physiological characteristics of the root systems of the higher-yielding corn variety DengHai 661 (DH661) and the commonly grown corn variety for northern China ZhengDan 958 (ZD958). The results clearly showed that DH661 consistently yielded higher than ZD958 in both years. The average biomass and grain yield of DH661 were 20.11% and 19.15% higher than those of ZD958. The roots DH661 grow faster than ZD98, it can get the depth to 160-200 cm at VT stage, but the roots of ZD958 get that depth at R3 stage. At the same time, the maximum of root biomass and average root length density (RLD), root actively absorbing area, root TTC reducing capacity after VT stage in both years were 83.06%, 43.30%, 58.10% and 40.38% higher than those of ZD958, respectively. Which can supplying more water and nutrient for the shoot, and improve the LAI, photosynthetic rate (in the later growth stage) and longer duration of high photosynthesis, make the contribution to the shoot growth and grain filling. All the results supporting the hypothesis that greater root systems lead to higher yield.