Emerging pathogens as a consequence of globalization and climate change: leafy vegetables as a case study

In the recent years (2010–2016), leafy vegetables have been found to be hosts for many new diseases. The causal agents of these diseases had often been known on other crops, but have appeared for the first time throughout the world on several cultivated vegetable hosts such as: Lactuca sativa, Diplotaxis spp., Eruca sativa, Valerianella olitoria, Ocimum basilicum and Spinacia oleracea. This review considers pathogens such as Alternaria spp. on basil and rocket, Fusarium equiseti on lettuce, rocket and radish, and Myrothecium verrucaria and M. roridum on lamb's lettuce, spinach and wild rocket. All these pathogens are seed-transmitted, a biological characteristic that raises the risk of worldwide dissemination. The role of climate change and globalization on the appearance of such diseases, and potential tools for their management under a climate change scenario, is discussed using leafy vegetables as a case study.