Is a reduced-tillering trait (tin) beneficial under elevated CO2 in four FACE environments?

Low, Markus and Tausz-Posch, S. and Rebetzke, G. and Dreccer, M. F. and Chapman, S. C. and Seneweera, S. and Fitzgerald, G. and Tausz, M. (2015) Is a reduced-tillering trait (tin) beneficial under elevated CO2 in four FACE environments? In: 17th Australian Agronomy Conference: Building Productive, Diverse and Sustainable Landscapes (AAC 2015), 20-24 Sept 2015, Hobart, Australia.

Abstract

The number of heads per m2 is an important yield component in wheat, and high yielding wheat types often produce many tillers and heads. Elevated CO2 (eCO2) generally promotes growth and yield of wheat, and this ‘CO2 fertilisation effect’ is commonly linked to increased production of biomass and tillers, and less to other yield components. In water limited environments where crops mature under increasingly dry conditions, high biomass productivity early in the season may lead to an early depletion of soil water reserves, and inabilityof the crop to fill grains. A restricted tillering trait, through a ‘tiller inhibition gene’ (‘tin’), has therefore been suggested in pre-breeding research and proven to be beneficial in such environments. In this study, we address the potential trade-offs between the response of yield to eCO2 and the restricted tillering trait. Two near-isogenic wheat lines, the freely tillering cultivar cv. Silverstar and a Silverstar line containing the
‘tin’ gene (Silverstar T65 “SSR T65”; CSIRO) conferring limited tillering ability, were grown side by side in four different environments (created by two different water supply levels – rainfed and supplemented by limited irrigation – during 2011 and 2012 growing seasons) in the Australian Grains Free Air Carbon dioxide Enrichment (AGFACE) facility in Horsham, Victoria. Our results indicate that eCO2 promoted tillering in both lines, that the responsiveness of yield and growth was not restricted by tin. The tin-line showed greater depression of leaf N under eCO2, but this did not translate to a CO2-related depression in grain protein.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: Copyright © 2015 Australian Society of Agronomy Inc.
Faculty / Department / School: Current - Institute for Agriculture and the Environment
Date Deposited: 24 Jun 2016 06:06
Last Modified: 20 Sep 2017 00:41
Uncontrolled Keywords: wheat; Free-Air Carbon dioxide Enrichment (FACE); tillering trait (tin); multi-environment experiment; dryland
Fields of Research : 05 Environmental Sciences > 0501 Ecological Applications > 050101 Ecological Impacts of Climate Change
Socio-Economic Objective: D Environment > 96 Environment > 9603 Climate and Climate Change > 960301 Climate Change Adaptation Measures
URI: http://eprints.usq.edu.au/id/eprint/28467

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