Colletotrichum species associated with fig (Ficus carica L.) in Malaysia

Abstract

Fig (Ficus carica L.) is one of the oldest fruits that is extensively cultivated worldwide. It has gained a lot of interest among growers due to its unique characteristics, nutritional values, and medicinal properties. Like other fruit crops, each part of the plant is susceptible to fungal diseases that affect fruit production and its quality. Samplings conducted from September 2018 to March 2019 showed that fig plants have been infected by leaf blight, stem canker, and anthracnose fruit rot. The present study aims to determine the causal pathogens of those diseases using morphological, molecular, and pathogenicity analyses. A total of 28 blighted leaves, 11 cankered stems, and 18 anthracnose-rotted fruits of F. carica were collected from different nurseries in several states in Malaysia. The results of morphological characterization, DNA sequences, and phylogenetic analysis of internal transcribed spacer (ITS), β-tubulin (tub2), and glyceraldehyde-3-phosphate dehydrogenase (gapdh) revealed that, of the 39 fungal isolates obtained, they belong to Colletotrichum fructicola (one isolate), C. siamense (30 isolates), and C. truncatum (eight isolates). From the 30 isolates of C. siamense, 10 isolates were obtained from leaves, eight isolates from stems, and 12 isolates from fruits, whereas eight isolates of C. truncatum, and one isolate of C. fructicola were obtained from leaves. The pathogenicity tests conducted on F. carica confirmed that C. fructicola, C. siamense, and C. truncatum were the causal pathogens of leaf blight, while stem canker and anthracnose fruit rot were caused by C. siamense. The present study highlighted three different Colletotrichum species namely C. fructicola, C. siamense, and C. truncatum associated with diseased figs (F. carica) in Malaysia.