Fig. 1.

Shoot (A) and root (B) relative growth rate (RGR) of 15 accessions of Melilotus siculus grown in nutrient solution for 7 d under control (aerated root zone), deoxygenated stagnant root zone, partial shoot submergence or full shoot submergence (the latter two treatments also with deoxygenated stagnant root zone). Plants subjected to partial submergence had an initial water column of 6.0 ± 0.9 cm above the root to shoot junction, so that 75 % of average shoot height submerged. Plants subjected to full submergence had a water column of 13.6 ± 0.8 cm above the root–shoot junction, which was approx. 5 cm of water above the top of plants. Plants were 28 d old when treatments were imposed. Values are means ± s.e. of four replicates. The significance of the main factors (‘accession’ and ‘treatment’) and the interaction of these two factors are shown in the P-values in the figure. Statistical analyses of these data are given in Tables 1 and 2.