Investigation of algal-derived polysaccharides against ramularia leaf spot (rls) in barley

Agriculture faces numerous challenges, including increasingly stringent regulatory standards, the effects of climate change, and the emergence of increasingly resistant pathogens capable of overcoming control measures, which can devastate crops. While the use of pesticides remains a major solution to combat many pathogens, their harmful impacts on the environment, biodiversity, and human health have been repeatedly demonstrated. This thesis, part of the BioCrop project, aims to develop environmentally friendly and effective solutions to combat barley ramularia leaf spot (RLS), a disease caused by the cryptogamic fungus Ramularia collo-cygni. RLS is increasing in Ireland, and effective, environmentally friendly pesticides are unavailable. Previous research has shown that molecules derived from algae, such as ulvans (from green algae), fucoidans and alginates (from brown algae), and carrageenans (from red algae), can be applied to plants to trigger their immune systems. In this context, three different methods were used to prepare extracts from several seaweed species collected along the West Irish Atlantic coast. The extracts were examined for their potential to stimulate the immune system of barley and to protect against infection by Ramularia collo-cygni, as well as for their direct antifungal potential against this fungus. The results reveal a diverse range of promising potential biostimulants/bioelicitors, offering interesting prospects for future applications in the sustainable management of Ramularia collo-cygni in barley. Seasonal monitoring of these seaweed molecules allowed the identification of optimal harvesting periods to maximise their effectiveness.

Funder

Department of Agriculture, Food and the Marine

Publisher

University of Galway

Rights

CC BY-NC-ND

cbn

Collections

University of Galway Theses (PhD Theses)