The relationships between leaf photosynthetic rate (<i>A</i>) and (a) leaf N content, and (b) Rubisco content and in Shanyou 63 (closed cycles) and Yangdao 6 (open cycles).
<p>The lines represent the following regression equations: (a) y = 0.12x+6.33 R<sup>2</sup> = 0.82 <i>P</i><0.01 for Shanyou 63; y = 0.17x−0.60 R<sup>2</sup> = 0.79 <i>P</i><0.01 for Yangdao 6; (b) y = 0.22x+8.59R<sup>2</sup> = 0.78 <i>P</i><0.01 for Shanyou 63; y = 0.40x−1.53 R<sup>2</sup> = 0.91 <i>P</i><0.01.</p
