Alex Seward: alex.seward@adelaide.edu.au, Caitlin Byrt: caitlin.byrt@anu.edu.au, Scott Sydenham: ssydenham@longreachpb.com.au, Stuart Roy: stuart.roy@adelaide.edu.au

67% of Australian agricultural area is at risk of transient salinity1, inhibiting plant growth and causing estimated agricultural losses of $519 million per annum2. The Portuguese wheat landrace Mocho de Espiga Branca (Mocho) has been found to accumulate high levels of sodium (Na+) in leaves and shoots, whilst maintaining healthy growth, indicating novel Na+ tolerance mechanisms not found in commercial wheat. High Na+ accumulation was found to be caused by a naturally occurring SNP in TaHKT1;5 that results in increased flux of Na+ from root to shoot.

The aim of this work is to further elucidate the mechanisms behind the increased salt tolerance and investigate whether increased leaf Na+ content leads to greater performance in water limited environments.

To investigate mechanisms behind increased sodium tolerance, a Mocho x Gladius recombinant inbred line (RIL) population was characterised under salt stress and control conditions, identifying 465 novel loci relating to growth performance. To determine whether enhanced ion accumulation in the shoot helps plants to grow better in low to moderate water conditions, a selection of RILs were grown in a mildly saline field (Ece1-5 = 2.35).

Three RILs were identified which accumulated >10x leaf Na+ with 5-28% yield improvement when compared to the parent Gladius. This poster will introduce current and future work, further investigating the potential benefits of Na+ accumulation in water limited environments and the tolerance mechanism behind it.

References:

Rengasamy, P., 2006. World salinization with emphasis on Australia. Journal of experimental botany, 57(5), pp.1017-1023.

OAG Audit, 2018. Dryland salinity is a significant cost and major risk to the State. Western Australian Auditor General’s Report, 8, pp.13-16.