Australian Wild Rice Populations: A Key Resource for Global Food Security

Abstract

Rice is one of the most important food crops contributing to the diet of large numbers of people especially in Asia. Rice (Oryza sativa) was domesticated in Asia many thousands of years ago and more recently independently in Africa. Wild rice populations are found around the tropical world. The extensive production of rice in many areas has displaced the wild populations that were the basis of the original domestications by humans. Recent research, reviewed here, has identified wild rice species in northern Australia that have been isolated from the impact of domestication in Asia. Wild rice populations contain novel alleles that are a source of desirable traits such as erect habit, disease resistance, large grain size, and unique starch properties. These populations include the most divergent genotypes within the primary gene pool of rice and more distant wild relatives. Genome sequencing also suggests the presence of populations that are close relatives of domesticated rice. Hybrid populations that demonstrate mechanisms of ongoing evolution of wild Oryza have been identified in the wild. These populations provide options for both new domestications and utilization of novel alleles to improve or adapt domesticated rice using conventional or preferably new breeding technologies. Climate change and growing food demands associated with population and economic growth are major challenges for agriculture including rice production. The availability of diverse genetic resources to support crop adaptation and new crop domestication is critical to continued production, and increased efforts to support in situ and ex situ conservation of wild Oryza and related species are warranted.

Rapid Accumulation of Proline Enhances Salinity Tolerance in Australian Wild Rice Oryza australiensis Domin

“…Efforts are ongoing to identify high salttolerant genetic resources for the improvement of salt tolerance in rice [6,42]. Wild rice O. australiensis is considered a potential candidate due to its ability to tolerate many abiotic and biotic stresses [39,[43][44][45][46]. However, tolerance to high concentrations of salt, a criterion for being a salt-tolerant trait donor, has not been studied in this wild rice species.…”

Phenotypic Characterization of Oryza nivara (Sharma et Shastry) Collected from Different Ecological Niches of Sri Lanka

“…The CWRs have a high genetic diversity and can contribute to new genetic diversity for agricultural sustainability [85]. For instance, previous research has indicated that several recently discovered wild rice species in northern Australia have unique alleles for distinct critical traits, which could improve the ability of cultivated rice to withstand climate change [86]. The ability of the same species to display distinct features under different environmental situations is referred to as phenotypic plasticity.…”

Plant adaptation to climate change—Where are we?

“…For example, Henry (2019) highlighted several recently identified wild rice species with most divergent genotypes in northern Australia containing novel alleles for various important traits, which could enhance the capacity of cultivated rice to tolerate climate change. During the past decade, dozens of review/ perspectives have been published to highlight the potential and importance of crop wild relatives in meeting global challenges (e.g., Brozynska et al, 2016;Zhang et al, 2017Zhang et al, , 2019Mammadov et al, 2018;Fernie & Yan, 2019;Henry, 2019). Nevertheless, few climate-adaptive casual genes identified in CWR have been applied to the development of crops that can withstand climate change.…”