Summary

Annual medics (Medicago spp.) form an important component in cereal crop rotations, improving soils through nitrogen fixation and are also a high value pasture species. B toxicity affects about 50% of the grain belt with neutral-alkaline soils of South Australia and Victoria. Low rainfall conditions, already common and likely to worsen in the face of climate change, increase the damage of high B levels.
A large range in response to B has been observed within the different medic species with intolerant lines showing a reduction of about 40% of dry matter versus only 10-15% in medium-tolerant lines (5).
Genetic variation with regards to B toxicity tolerance exists in many plant species investigated, with no exception for annual medics. Genetic variation in cereal crops has been successfully used to develop B tolerant varieties in wheat and barley. Molecular tools in the form of closely linked or diagnostic markers have been developed for these cereal species but not yet for pastures.
In this project we will address this deficit and utilise the genetic diversity of medics and publicly available genomic resources to develop closely linked and most likely even diagnostic markers. These markers shall be used to ensure that B tolerance is part of newly developed annual medic varieties.

Program

Pasture Seeds

Research Organisation

Minister for Primary Industries and Regional Development acting through the South Australian Research and Development Institute

Objective Summary

Growers already have access to B tolerant cereal crops and keep doing so in newly developed varieties as perfect markers enable efficient selection for this trait. Aim of this project is to establish molecular markers as the fastest approach to develop the most suitable annual medics that can be used in crop rotation with these cereals on B toxic soils.