Tianhua He

Barley(Hordeum vulgare L.) is one the most important cereal crops in the world and cultivated both in highly productive agricultural regions as well as in marginal environments prone to adverse conditions.As a particularly resilient crop compared to other cereals such as wheat and rice,barley has the ability to adapt to biotic and abiotic stresses,holding much potential to increase production in marginal areas to sustain food security.Barley genome sequences from over 20 accessions are close to be completed at the reference genome levels by the end of this year,which include wild barley,landraces and cultivated barley.The genome sequences will provide unprecedent resources for genomics breeding Seventy percent more food needs to be produced to meet the global human population projected to grow into nine billion by 2050.Efforts of achieving this substantial increase have been retarded by the adverse impact of projected climate change on crop yield.Modelling studies on crop growth and climate change have produced robust estimates of the potential impact on global crop production under different emission scenarios.However,uncertainty in future CO_2 emission magnifies the uncertainties in modelling the impact of future climate change on global crop production.Furthermore,previous studies on predicting the impact of climate change on crop yield assume unchanged crop varieties and agronomic practice.We use an example to demonstrate how genomics selection can be used to improve barley yield under climate change

Significant climate changes are evident across Australia with declining rainfall and rising temperature, in conjunction with more frequent fire. Significant species loss and range contractions have been predicted, however the validity of these predictions is uncertain with critical gaps remaining in our understanding of the intrinsic capacity of species to respond to climate change. We quantified genome wide adaptive genetic variation in populations of Banksia attenuata, a prominent woody plant of multiple vegetation types in southwest Australia, evaluated the impact of declining rainfall, rising temperature and shortened fire intervals on population adaptive genetic variation. We characterised candidate genes associated with rainfall gradients, temperature, and fire interval through environmental association analysis. Population adaptive genetic variation was significantly impacted by shortened fire intervals, while declining rainfall and rising temperature have not had detectable influence so far. Candidate genes associated with rainfall and high temperature are diverse, with polymorphic alleles present in populations, while genes associated with specific fire intervals are fixed in one allele. Gene annotation further revealed four genes with function in stress tolerance, regulation of stomatal opening and closure, energy use, and morphogenesis with adaptation to climate and fire interval. B. attenuata, and perhaps other species with similar life history and distribution, may tolerate some further change in rainfall and temperature through evolutionary adaptation based on their adaptive genetic variation. However, the capacity to survive future climate change may be compromised by change in fire regime, and the capacity to survive more frequent fire and further environmental fluctuations is uncertain.

The effects of climate change, particularly altered rainfall patterns, are apparent across Australia. In Southwestern Australia, a biodiversity hotspot, decreased annual rainfall is causing concern for the persistence of native flora. The ability of Australian species to rapidly select for drought tolerance in response to decreased rainfall is largely unknown, yet this knowledge is required to develop future management and conservation strategies. This research aims to determine whether seed-banks of selected species can potentially mitigate effects of a drying climate through rapid selection and adaptation. It is hypothesised that the seed-bank of a species can increase resilience to climate change by providing a range of genetic material for rapid selection. Eight locations where fire was followed by a wet, dry or average winter were identified at Eneabba, Southwestern Australia. At each location, seed was collected from five serotinous, fire-killed species; Banksia hookeriana, Banksia leptophylla, Hakea costata, Hakea polyanthema and Beaufortia elegans. Seed was germinated, and divided into three drought treatments: 100%, 75%, and 50% mean winter rainfall equivalent. Post-spring, seedlings will be harvested and dry-weight of roots/shoots determined. A larger proportion of seedlings descended from plants recruited post-fire in dry winters are expected to exhibit tolerance to drought treatments than those descended from plants recruited in average or wet winters. This experiment is part of a broader study on evolutionary adaptation in Western Australian species, which aims to determine the ability of species to rapidly evolve in response to climate change, and assist in informing approaches to adaptive conservation management.