International Journal of Agricultural Policy and Research
Vol.4 (7), pp. 117-127, July 2016
Available online at https://www.journalissues.org/IJAPR/
Article 16/ID/JPR046/11/ pages
Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License .
Original Research Article
Dynamics and contribution of stem water-soluble carbohydrates to grain yield in two wheat lines contrasted under Drought and elevated CO2 conditions
Wiza Mphande*1, Marc E. Nicolas2, Saman Seneweera3, Helale Bahrami4 and Nchimunya Bbebe1
1Department of Agriculture, School of Agriculture and Natural Resources, Mulungushi University, Kabwe, Zambia.
2Department of Agriculture and Food Systems, Melbourne School of Land and Environment,The University of Melbourne, Parkville, Victoria 3010, Australia.
3Department of Agriculture and Food Systems, Melbourne School of Land and Environment, The University of Melbourne, Water Street, Creswick, Victoria 3363, Australia.
4Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia.
*Corresponding Author Email: wmphande(at)mu.ac.zm,wizac2008(at)gmail.com
Stem water-soluble carbohydrates (stem WSC) are a source of carbon for grain filling in wheat that become more important in maintaining grain yield during post-anthesis period when current photosynthesis declines due water stress. Stem WSC are therefore expected to be one of the key traits in adapting wheat to water-limited environments. The aim of this study was to determine dynamics and role of stem WSC in maintaining grain yield traits of wheat under post-anthesis water deficit and elevated CO2 (eCO2) conditions. A research was conducted at the Australian Grains and Free-Air CO2 Enrichment Facility (AGFACE) in Horsham, Victoria. Two Seri/Babax (SB) wheat lines, SB03 and SB62, were grown under varying combinations of water and CO2. Results showed that WSC contributed 20-32 % of grain yield/spike (highest contribution was for SB62 under eCO2). Elevated CO2 (550 ppm) increased the accumulation of stem WSC and grain yield m-2, the two lines were not significantly different on the latter variable. Higher WSC increased grain yield/spike under drought conditions regardless of amount of CO2 available. The stem WSC contributed to grain yield under all conditions and not just under eCO2 x drought conditions. Replication under different agro-ecological environments is required to confirm these.
Key words: Wheat, crop adaptation, grain yield, water-soluble carbohydrates, elevated CO2, drought