Chin J Plan Ecolo ›› 2010, Vol. 34 ›› Issue (2): 144-150.DOI: 10.3773/j.issn.1005-264x.2010.02.005

Special Issue: 稳定同位素生态学

• Special feature: Stable isotope ecology • Previous Articles     Next Articles

Difference in δ13C and gas exchange parameters among Populus tomentosa clones

HE Qian3,1; LI Ji-Yue3,1*; SHEN Ying-Bai2; CHEN Xiao-Yang3; SHANG Fu-Hua1;HU Lei1; ZHANG Zhi-Yi2*   

  1. 1Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China; 2Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, Beijing Forestry University, Beijing 100083, China; and 3College of Forestry, South China Agricultural University, Guangzhou 510642, China
  • Online:2010-02-01 Published:2010-02-01
  • Contact: LI Ji-Yue;ZHANG Zhi-Yi

Abstract: Aims Fast, efficient breeding of fast-growth and high water use efficiency (WUE) in Populus tomentosa clones is a pressing need for afforestation in arid and semi-arid regions. There is much research on the correlation be-tween stable carbon isotope and WUE in crops and a few trees, but little in different clones of P. tomentosa. Our objective was to explore the application of δ13C on selection of clones with high photosynthesis and WUE. Methods We examined 13 clones of Populus-grafted seedlings in Beijing Forestry University (39°46′ N, 116°19′ E) Nursery in Beijing, China. We studied leaf δ13C of the seedlings by MAT-251-MS in two different growth periods (mid-July and September) and gas exchange parameters (net photosynthetic rate (Pn), transpiration rate (Tr), instantaneous water use efficiency (WUEi), stomatal conductance (Gs) and intercellular CO2 concentration (Ci)) by LI-6400 portable photosynthesis system between 9:30 and 11:30 a.m. in the same periods. Important findings Leaf δ13C, Tr, WUEi, Gs and Ci significantly differed between the periods and among clones. Leaf δ13C and WUEi were higher in July than September; however, Tr, Gs and Ci were lower in July than September and Pn showed no significant difference between periods. The main reason for the difference of leaf δ13C was seasonal variation. Leaf δ13C and WUEi of the clones were consistent during the same period, i.e, the higher WUEi appeared in clones of 30, 42, 46, 83, BL2 and BL5 with higher δ13C and the lower WUEi occurred in clones of B331 and TG34 with lower δ13C. There was strong positive correlation between δ13C and WUEi (r = 0.739 0 and 0.545 8 in July and September, respectively); therefore, high δ13C can be used as an effective indicator of high WUEi in Populus. Clones with higher WUEi may have moderate or low Gs and Ci, but not necessarily high Pn.