The Colletotrichum species complex such as C

The Colletotrichum species complex such as C. gloeosporioides, C. boninense and C. acutatum have been separated into many different species (Weir et al. 2012, Damm et al. 2012a, 2012b; Liu et al. 2014). However, in China the identification of Colletotrichum species on mango was mainly rely on conidial morphology and ITS sequences (Sun et al. 2016), and the combined data were still limited and insufficient to distinguish closely related taxa in the three species complexes mentioned above. Former research records about Colletotrichum species on mango were mostly sampled from small and fragmented provincial areas, representing poorly about the actual species diversity in the vast mango growing region in China.
In our previous study, three Colletotrichum species (C. asianum, C. fructicola and C. siamense) causing mango anthracnose in Guangxi province in China have been reported (Mo et al. 2018). However, the growing season and the harvesting time of mango in seven provinces of mango growing region varied with ecological environment, climatic conditions and variety differences, the causal agents of mango anthracnose in the different provinces could be varied.
Genetic diversity is often related to evolutionary potential, and ability to adapt to changing environmental conditions (McDonald and Linde 2002). According to our current understanding of the gene-for-gene hypothesis, resistance genes lose resistance quickly when faced with a complex pathogen population. Understanding the population structure of pathogens can provide insights into the best breeding strategies for persistent resistance to mangoes.
The objectives of this study are (1) to identify Colletotrichum species associated with mango anthracnose in six provinces of China using cultural characteristics, conidial and appressorial morphology as well as multi loci sequencing data for phylogenetic analyses; (2) to test the virulence of isolates from different geographic locations over the major mango growing areas in mainland China, and the variation of isolates existing in every geographic origin investigated; and (3) to reveal the differences for Colletotrichum species population structure within each of the provincial geographic locations researched.