Contents Chapter 1 General introduction 7 Chapter 2 Worse comes to worst: Bananas and Panama diseasewhen 23 plant and pathogen clones meet Chapter 3 A Loop-Mediated Isothermal Amplification assay based on 34 unique markers derived from genotyping by sequencing data for rapid in-plant diagnosis of Fusarium oxysporum f.sp. cubense tropical race 4 in banana Chapter 4 The phylogeography of the banana Fusarium wilt pathogen 55 Fusarium oxysporum f.sp. cubense Chapter 5 Unveiling the pathogenicity of the widest array of genetically 95 diverse Fusarium oxysporum f.sp. cubense isolates on 'Gros Michel' and 'Grand Naine' banana cultivars Chapter 6 General discussion 113 Summaries 132 8 Chapter 1 Introduction 8 BANANAS: IMPORTANCE, ORIGIN AND FUNGAL DISEASES Bananas are an essential staple food for developing countries, particularly in Africa where the consumption of banana is higher than in Asia and Latin America, and generates substantial economic income for small and large producers (Frison & Sharrock, 1998). As staple food with a high carbohydrate content (Pareek, 2016), bananas are an important calorie source in the diet of over 500 million inhabitants in banana producing countries (Aurore et al., 2009). Bananas are not only eaten raw as dessert or sweet bananas, but also cooked such as plantains and cooking bananas. Additionally, they are used as raw materials in diverse regional products, for instance in beer, juice or flour production (Aurore et al., 2009; Ekesa et al., 2012). Equally important, bananas are a cash crop for small farmers that serve domestic markets and for banana producing countries exporting to international markets. Nearly 85% of the total production of bananas is designated to local markets and only 15% enters international markets (FAOSTAT, 2013). In 2014, world banana production reached 78.8 million tonnes, with India contributing with 38% of produced bananas (FruitTrop, 2017). In descending order, India, Uganda, China, The Philippines, Ecuador and Brazil are globally the largest banana producing countries (Fig. 1). Importantly, East Africa is the largest bananaproducing and consuming region in Africa, with Uganda having the highest consumption of bananas that may exceed 1.6 kilograms per capita per day (Thornton & Cramer, 2012). Notably, the export trade of bananas is particularly important for The Philippines and several exporting countries in