Article,
Intraspecific variation in growth and yield response to elevated CO2 in wheat depends on the differences of leaf mass per unit area
Functional Plant Biology, 40 (2): 185+ (2013)
DOI: 10.1071/fp12057
Abstract
In order to investigate the underlying physiological mechanism of intraspecific variation in plant growth and yield response to elevated CO2 concentration CO2, seven cultivars of spring wheat (Triticum aestivum L.) were grown at either ambient CO2 (\~384 μmol mol–1) or elevated CO2 (700 μmol mol–1) in temperature controlled glasshouses. Grain yield increased under elevated CO2 by an average of 38\% across all seven cultivars, and this was correlated with increases in both spike number (productive tillers) (r = 0.868) and aboveground biomass (r = 0.942). Across all the cultivars, flag leaf photosynthesis rate (A) increased by an average of 57\% at elevated CO2. The response of A to elevated CO2 ranged from 31\% (in cv. H45) to 75\% (in cv. Silverstar). Only H45 showed A acclimation to elevated CO2, which was characterised by lower maximum Rubisco carboxylation efficiency, maximum electron transport rate and leaf N concentration. Leaf level traits responsible for plant growth, such as leaf mass per unit area (LMA), carbon (C), N content on an area basis (NLA) and the C : N increased at elevated CO2. LMA stimulation ranged from 0\% to 85\% and was clearly associated with increased NLA. Both of these traits were positively correlated with grain yield, suggesting that differences in LMA play an important role in determining the grain yield response to elevated CO2. Thus increased LMA can be used as a new trait to select cultivars for a future CO2-rich atmosphere.
