Does a freely tillering wheat cultivar benefit more from elevated CO2 than a restricted tillering cultivar in a water-limited environment?

Tausz-Posch, Sabine and Dempsey, Raymond W. and Seneweera, Saman and Norton, Robert M. and Fitzgerald, Glenn and Tausz, Michael (2015) Does a freely tillering wheat cultivar benefit more from elevated CO2 than a restricted tillering cultivar in a water-limited environment? European Journal of Agronomy, 64. pp. 21-28. ISSN 1161-0301


This study addresses whether a freely tillering wheat cultivar with greater vegetative sink strength (cv. 'Silverstar') can benefit more from increasing atmospheric CO2 concentration [CO2] than a restricted tillering cultivar with greater reproductive sink strength (cv. H45) in a water-limited cropping system. Growth, yield, yield components and nitrogen at three developmental stages (stem elongation, anthesis, maturity) and water soluble carbohydrates (WSC, anthesis) were evaluated at two CO2 concentrations (ambient [CO2], ~395ppm, elevated e[CO2], ~550ppm) across six environments using the Australian Grains Free Air CO2 Enrichment (AGFACE) facility. Cv. 'Silverstar' had more tillers than cv. 'H45' throughout development; whereas, cv. 'H45 had greater WSC storage and more and heavier kernels per spike. CO2 enrichment stimulated grain yield in both cultivars similarly, but this stimulation was caused differently: For cv. 'Silverstar', grain yield increase was exclusively linked to an increased number of fertile tillers; whereas, in cv. 'H45', yield stimulation was additionally associated with increased kernel weight and kernel numbers per spike. We conclude that in a Mediterranean-type, water-limited environment high tillering capacity alone does not ensure greater benefits from CO2 fertilization but that both pre and post-anthesis source-sink relationships play a significant role in this environment as well.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Restricted access to published version in accordance with publisher copyright policy.
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Crop Health
Date Deposited: 09 Jan 2015 00:20
Last Modified: 24 Jun 2016 04:00
Uncontrolled Keywords: Triticum aestivum; free air carbon dioxide enrichment (FACE); growth; low rainfall; source-sink relations; Triticum aestivum L.; yield
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060705 Plant Physiology
05 Environmental Sciences > 0502 Environmental Science and Management > 050205 Environmental Management
05 Environmental Sciences > 0501 Ecological Applications > 050101 Ecological Impacts of Climate Change
Socio-Economic Objective: B Economic Development > 82 Plant Production and Plant Primary Products > 8205 Winter Grains and Oilseeds > 820507 Wheat
D Environment > 96 Environment > 9603 Climate and Climate Change > 960301 Climate Change Adaptation Measures
Identification Number or DOI: 10.1016/j.eja.2014.12.009

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