Bread Wheat With High Salinity and Sodicity Tolerance.

Yusuf Genc,Judy Cheong,Yongle Li,Tim Sutton,Klaus Oldach,Graham Lyons,Julian Taylor,Marie Appelbee

doi:10.3389/fpls.2019.01280

Yusuf Genc, Judy Cheong + Show 6 more

Open Access

https://doi.org/10.3389/fpls.2019.01280

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Abstract

Soil salinity and sodicity are major constraints to global cereal production, but breeding for tolerance has been slow. Narrow gene pools, over-emphasis on the sodium (Na+) exclusion mechanism, little attention to osmotic stress/tissue tolerance mechanism(s) in which accumulation of inorganic ions such as Na+ is implicated, and lack of a suitable screening method have impaired progress. The aims of this study were to discover novel genes for Na+ accumulation using genome-wide association studies, compare growth responses to salinity and sodicity in low-Na+ bread Westonia with Nax1 and Nax2 genes and high-Na+ bread wheat Baart-46, and evaluate growth responses to salinity and sodicity in bread wheats with varying leaf Na+ concentrations. The novel high-Na+ bread wheat germplasm, MW#293, had higher grain yield under salinity and sodicity, in absolute and relative terms, than the other bread wheat entries tested. Genes associated with high Na+ accumulation in bread wheat were identified, which may be involved in tissue tolerance/osmotic adjustment. As most modern bread wheats are efficient at excluding Na+, further reduction in plant Na+ is unlikely to provide agronomic benefit. The salinity and sodicity tolerant germplasm MW#293 provides an opportunity for the development of future salinity/sodicity tolerant bread wheat.

Highlights

Soil salinity and sodicity severely constrain crop production in Australia and worldwide
Given the benefits of Na+ exclusion under sodicity but not salinity observed in our initial study (Genc et al, 2016), here we screened a bread wheat diversity set under sodicity to determine genetic variation for Na+ exclusion
The only exceptions to this were two bread wheat germplasm lines (MW#451 and MW#293; approx. >15,000 mg Na+ kg-1 DW) which grouped with the durum wheats

Summary

Introduction

Soil salinity and sodicity severely constrain crop production in Australia and worldwide. The total global area of saline and sodic soils is estimated to be around 830 million hectares, more than 6% of the world’s land (Martinez-Beltran and Manzur, 2005) and rising (Acosta-Motos et al, 2017; Bennett et al, 2013; Shrivastava and Kumar, 2015). Salinity and Sodicity Tolerant Bread Wheat reported (Rengasamy, 2002). These studies highlight the scale of lost productivity on saline and sodic soils, and the great opportunity if yield in these environments can be improved

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