Biodiversity Challenges with Climate Change

Genetic resources, mainly in ex situ genebanks, have an important role in the adaptation of agriculture to climate change. There is an urgent need to collect traditional landraces where they are still grown across diverse environments, to access genes with tolerance of abiotic stresses and resistance to biotic stresses. The genetic diversity in wild relatives of crops is also under threat due to loss of habitats as the population pressures on agricultural land increases. Yet this diversity is often wider than in domestic crops for addressing the new challenges of climate change. This will result in increased incidence of drought, high temperature stress, frost associated with lower rainfall, and increased levels of CO2 in most temperate agricultural zones. A combination of genetic and farm management solutions will be needed. Disease incidence and severity will also be affected. The seriousness of most fungal diseases except Rhizoctonia is likely to be less with the expected warmer and drier conditions, however in areas with wetter conditions powdery mildew in peas, Schlerotinia moulds and Phytophtera may be more important. Climate change may favour the build up of aphid vectors, with potential increase in viral diseases. Especially for viral and bacterail pathogens, the sourcing of genetic resistance will be important. Wild relatives of crops (although unknown for faba bean), and marker assisted selection, will be important for breeding resistance to Aschochyta, Botrytis, anthracnose, powdery and downy mildew, and for the many soil borne diseases. Continued breeding for resistances to an imposing array of viruses will be required, with assitance from biotechnology.