Intraspecific variation in growth and yield response to elevated CO 2 in wheat depends on the differences of leaf mass per unit area.

Autor: Thilakarathne, Chamindathee L., Tausz-Posch, Sabine, Cane, Karen, Norton, Robert M., Tausz, Michael, Seneweera, Saman
Předmět:
Zdroj: Functional Plant Biology; 2013, Vol. 40 Issue 2, p5-5, 1p
Abstrakt: In order to investigate the underlying physiological mechanism of intraspecific variation in plant growth and yield response to elevated CO [sub 2] concentration [CO [sub 2]], seven cultivars of spring wheat (Triticum aestivum L.) were grown at either ambient [CO [sub 2]] (~384 μmol mol-1) or elevated [CO [sub 2]] (700 μmol mol-1) in temperature controlled glasshouses. Grain yield increased under elevated [CO [sub 2]] 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 [CO [sub 2]]. The response of A to elevated [CO [sub 2]] ranged from 31% (in cv. H45) to 75% (in cv. Silverstar). Only H45 showed A acclimation to elevated [CO [sub 2]], 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 ([N] [sub LA]) and the C : N increased at elevated [CO [sub 2]]. LMA stimulation ranged from 0% to 85% and was clearly associated with increased [N] [sub LA]. 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 [CO [sub 2]]. Thus increased LMA can be used as a new trait to select cultivars for a future [CO [sub 2]]-rich atmosphere. Optimisation of plant responses to increasing CO [sub 2] is a key strategy to achieve future food security. Identification of the leaf level traits that can capture the CO [sub 2] response will be easily adopted for the future wheat breeding programs. This work demonstrates the genetic capacity to adjust the leaf level traits, such as leaf mass per area and leaf nitrogen status to capture the CO [sub 2] response. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje