Quantitative Analysis of Soil Sheath Distribution in Maize Root Systems

Abstract

The soil sheath (SS) distribution and its change with the passage of time in maize root systems were investigated. Maize seeds were planted in deep pots, and the roots were sampled at 2, 3, 4 and 6 weeks after sowing. The distribution of SS on the axile roots and the 1st order lateral roots was examined quantitatively. On axile roots, as classified by the nodes from which they emerged, younger roots were more thickly sheathed than older ones. A similar tendency was observed in the 1st order lateral roots. Significant correlations were observed between the thickness of SS, and the root length or the diameter in one part of the axile roots. L-type 1st order lateral roots (branched 1st order laterals) were sheathed more than S-type lateral roots (non-branched). Quantitative analysis revealed that the amount of SS was closely related to the root length, thickness, branching capacity, and root age.