Genetic differentiation and recombination among geographic populations of the fungal pathogen Colletotrichum truncatum from chili peppers in China

Abstract

Colletotrichum truncatum is an extremely important fungal pathogen. It can cause diseases both in humans and in over 460 plant species. However, little is known about its genetic diversity within and among populations. One of the major plant hosts of C. truncatum is pepper, and China is one of the main pepper-producing countries in the world. Here, we propose the hypotheses that geography has a major influence on the relationships among populations of C. truncatum in China and that infections in different populations need to be managed differently. To test these hypotheses, we obtained and analyzed 266 C. truncatum isolates from 13 regions representing the main pepper-growing areas throughout China. The analysis based on nine microsatellite markers identified high intrapopulation genetic diversity, evidence of sexual recombination, and geographic differentiation. The genetic differentiation was positively correlated with geographic distance, with the southern and northern China populations grouped in two distinct clusters. Interestingly, isolates collected from the pepper-breeding center harbored the most private alleles. The results suggest that the geographic populations of C. truncatum on peppers in China are genetically differentiated and should be managed accordingly. Our study also provides a solid foundation from which to further explore the global genetic epidemiology of C. truncatum in both plants and humans.

Population Genetics of Hirsutella rhossiliensis, a Dominant Parasite of Cyst Nematode Juveniles on a Continental Scale

“…We suggest that the North Pacific Ocean may be a boundary separating the Chinese population and the American population of H. rhossiliensis because of limited opportunities to disperse via wind or soil. A similar geography-based separation has been reported in Colletotrichum truncatum from chili peppers in China that were genetically differentiated into southern and northern populations (61). Previously, we found significant differences among local populations of H. minnesotensis from China and the United States, where isolation by geography plays a key role in genetic differentiation (22).…”

Assessing the Risk for Resistance and Elucidating the Genetics of Colletotrichum truncatum That Is Only Sensitive to Some DMI Fungicides

“…A total of 112 C. truncatum isolates were collected in 2011, 2012, and 2013 from 13 regions in China in a previous study ( Diao et al, 2015 ); Background information of the isolates is provided in Supplementary Table S2 . Based on both morphological characteristics and phylogenetic analysis, all 112 isolates were previously determined to be C. truncatum ( Damm et al, 2009 ; Diao et al, 2015 ).…”

Colletotrichum species associated with chili anthracnose in Australia

“…gloeosporioides in Korea (Kim et al ., ), Thailand (Than et al ., ) and Indonesia (Voorrips et al ., ); C . truncatum in Australia, China, India and Thailand (Sharma et al ., ; Ranathunge et al ., ; Diao et al ., ); C . acutatum from almost all chili‐growing countries, including China, India, Korea, New Zealand, Sri Lanka, Thailand, the USA and Indonesia (Simmonds, ; Harp et al ., ; Than et al ., ; Damm et al ., ); and C .…”

“…Chili anthracnose is a major disease of chili fruit worldwide and causes significant yield loss, as well as reducing the marketability of the fruit. Anthracnose disease of chili is caused by a complex of Colletotrichum species, reported as C. fructicola and C. siamense in India (Sharma & Shenoy, 2014); C. gloeosporioides in Korea (Kim et al, 1999), Thailand (Than et al, 2008) and Indonesia (Voorrips et al, 2004); C. truncatum in Australia, China, India and Thailand (Sharma et al, 2005;Ranathunge et al, 2012;Diao et al, 2015); C. acutatum from almost all chili-growing countries, including China, India, Korea, New Zealand, Sri Lanka, Thailand, the USA and Indonesia (Simmonds, 1968;Harp et al, 2008;Than et al, 2008;Damm et al, 2012); and C. coccodes in New Zealand and India (Johnston & Jones, 1997;Sharma et al, 2011;Cannon et al, 2012). The identities of many of these species are uncertain as they have not been confirmed by modern molecular methods.…”