Comparison between the estimates of mesophyll conductance of CO<sub>2</sub> (<i>g</i><sub>m</sub>) obtained by applying two independent methods: the variable <i>J</i> method and the ‘δ13C of recently synthesised sugars’ method (linear regression: R<sup>2</sup> = 0.932; <i>F</i><sub>1,9</sub> = 122.750; <i>P</i> = 1.515×10<sup>−6</sup>).
<p>Each data point represents the average value of three observations based upon the Δ13C of recently synthesised sugars and six to fourteen gas-exchange measurements utilising the variable J method. Error bars as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109054#pone-0109054-g001" target="_blank">Figure 1</a>. The regression line excludes the two data points on the right of the graph (IR64 and PS80) with anomalously high <i>g</i><sub>m</sub> derived from the δ13C of recently synthesised sugars. Numbers next to data points indicate <i>Oryza sativa</i> variety as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109054#pone-0109054-g001" target="_blank">Figure 1</a>.</p
