Application of anthracnose resistance-associated molecular markers in the detection of resistant chili pepper cultivars in Vietnam
Introduction: Colletotrichum species is responsible for anthracnose, a worldwide serious disease, causing an important loss in chili pepper production. Therefore, screening disease resistant and sensitive chili pepper cultivars in Vietnam is important not only for in-depth studies of disease resistance-associated molecular mechanisms but also for chili production improvement via molecular marker-assisted breeding in Vietnam.
Methods: To this end, in this study, two Colletotrichum isolates were obtained from the infected fruits collected from chili pepper (Capsicum annuum) fields in Tra Vinh province. According to the morphology analysis and the sequencing results of the internal transcribed spacer (ITS) regions, these isolates were identified as C. scovillei and C. acutatum. In order to identify the anthracnose-resistant chili pepper cultivars, the pathogenicity test was conducted by infecting fully developed green fruits of eleven chili pepper cultivars with the two isolated Colletotrichum strains.
Results: CN404 and HNCS were the two strongest anthracnoseresistant cultivars. Two chili pepper cultivars, TV3 and PN400, showed different resistance tendencies to each Colletotrichum isolates. Four different SSR molecular markers were used in this study to identify the potential molecular markers associated with anthracnose resistance traits in chili pepper cultivars. Among the four examined markers, HpmsE126 was detected in two anthracnoseresistant chili pepper cultivars, suggesting its close relation to the anthracnose resistance trait in chili pepper.
Conclusion: Given that two of the three most anthracnose-resistant cultivars, CN404 and TV3, possess HpmsE126 marker, this marker can be used to detect anthracnose-resistant lines in chili pepper breeding in Vietnam.