Carbon physiological integration pattern of whole plant of Zoysia japonica and its ecological effects under different light conditions

Under four light treatment conditions (treatment I: full light treatment to all multiple-node ramets; treatment: shading treatment to all multiple-node ramets; treatment II: shading treatment only to multiple-node ramets fed with ¹³CO₂; treatment III: full light treatment only to multiple-node ramets fed with ¹³CO₂), ¹³CO₂ was fed from the basal, middle and distal ramets (i. e. the seventh, the seventeenth and the twenty-fourth multiple-node ramets) of clonal plant of Zoysia japonica Steud., and ¹³C distribution pattern and translocation characteristics in different organs of clonal plant of Z. japonica were studied. The results show that after ¹³CO₂ fed from different part ramets, ¹³C translocation pattern all appears the trend of bidirectional transport toward basal and toward distal along the stolons taking fed ramets as the starting point, but the translocation gradient value toward distal all is lower than that of toward basal and the translocation distance toward distal is all bigger than that of toward basal, meaning the distal translocation of ¹³C has more advantage. There is a certain difference in translocation pattern of ¹³C in ramet leaf, stolon and multiple-node root. The δ¹³C value in ramet leaf fed with ¹³CO₂ is higher but that in other ramet leaves decreases sharply. The δ¹³C value in stolon is generally lower but the ¹³C translocation range is extensive. The δ¹³C value in multiple-node root is higher than that in stolon when ¹³CO₂ is fed from the basal and middle ramet leaves, while that is lower than that in stolon when ¹³CO₂ is fed from the distal ramet leaves. From the translocation range and gradient value, generally, the ¹³C gradient value in ramet leaf is significantly higher than that in multiple-node root and stolon. And in stolon, ¹³C translocation appears a gentle pattern but its translocation distance is the farthest. Moreover, under four light treatment conditions, the gradient value of ¹³C translocation toward basal or distal directions in multiple-node root and stolon is the highest and the ¹³C translocation distance in all organs is the farthest in treatment IV. But the gradient value of ¹³C translocation toward basal or distal directions in ramet leaf is the highest respectively in treatment II, IIIand I when ¹³CO₂ is fed from the basal, middle and distal ramets. According to these experimental results, the distribution pattern of photosynthetic products and its ecological effect in different organs of clonal plant of Z. japonica under different light conditions are discusse.