Figure 4

Architectural traits related to rhizosphere aeration of contrasting lines in IR29/Pokkali population. Representative images of the pith cavity in shoots (a) and primary roots (b) in the three lines were documented after 5 days of Fe stress. Red arrows indicate the aerenchyma. The diameter of pith cavity (c) and primary roots (d) were determined and vertical bars indicate standard errors of means (n = 4). The numbers of lateral fine roots within 1 cm distance from primary roots were counted (e), and vertical bars represent standard errors of means (n = 20). The total length of roots (f) was determined by root scanning; vertical bars indicate standard errors of means of n = 3 (IR29 and FL510) or n = 4 (Pokkali). Different letters indicate significant differences between genotypes by LSD-test (p < 0.05).