Unravelling beneficial multi-species interactions in a cereal crop system

点击翻译按钮获取中文摘要

Making sure we can feed the growing world population is a problem everyone can understand. How we can do this sustainably, i.e. while preserving the resources needed by future generations, is a current focus in agricultural and ecological research. In particular, we need to understand how the severity and distribution of pests and disease will change in response to the increasingly variable climate the world is experiencing, such as droughts, heat waves, and flooding. The continuing use of pesticides to control insects has led to the development of resistance in insect populations, and this means we have a reduced ability to control these pests with chemicals. The development of knowledge-based practical alternatives for farmers is vital in supporting sustainable food security strategies. In a natural setting, many species interact and coexist together to form a well-functioning ecological system. In agricultural systems, many of these interactions are disrupted when the soil and surroundings are disturbed. However, we can use our knowledge of natural communities and exploit known beneficial interactions to help our crop systems. For example, biological control promotes the ecosystem services of predators to control pest populations, and is used successfully in many closed greenhouse systems. Another example is the use of beneficial microbes (bacteria and fungi) that can increase plant growth and survival. Beneficial bacteria around the roots of plants can help the plant in many ways, including providing extra nutrients or making them more resistant to disease or insect pests. The application of beneficial plant microbes in agriculture has been hindered by inconsistent results across different environments. While one type of bacteria might be beneficial on its own, once in a mixed community (not just with other bacteria, but also including things like insects or earthworms) it can respond differently.This project aims to understand how we can use specific types of soil bacteria to promote plant health, through increased plant growth and suppression of aphid populations in agricultural systems. Aphids are herbivorous insects that feed on plant sap, and they can transmit viruses that are highly damaging to crop plants, leading to significant economic losses. I will inoculate barley plants with beneficial microbes to determine the effect on reducing cereal aphid pests. Through a combination of controlled greenhouse and field experiments, I will understand how different crop cultivars vary in their response to these microbes, and how earthworms or limited nutrient availability can modify the effects on plant growth and aphid suppression. When transferring such results to the field, it is important to understand how the natural soil microbial community may also change the outcome of the results. I will assess the impact of the native microbes in the field soil on the establishment of inoculated microbes, and how this can alter the effects on plant growth and aphid suppression. I will further identify molecular pathways in both the barley plants and bacterial communities that lead to increased resistance to the aphid pests. This can help to develop future insect-resistant crop cultivars and pest control strategies. Finally, I will run agricultural field experiments using different communities of inoculated beneficial microbes on barley crops. Such field experiments are an essential step towards developing practical solutions for farmers, and to assess the impact on pest control in large-scale systems. Based at The University of Liverpool, this project will investigate the role of species interactions in sustainable agriculture, identifying interactions that show consistent beneficial effects on the crop plants and that can be exploited in the future.