Development of a Mitochondrial SCAR Marker Related to Susceptibility of Banana (Musa AAA Cavendish) to Fusarium oxysporum f. sp. Cubense Race 4

Abstract

The use of resistant cultivars is an effective method for the control of banana (Musa spp.) Fusarium wilt caused by race 4 of Fusarium oxysporum f. sp. cubense (Foc4). However, selection of disease-resistant cultivars requires large-scale field evaluations and is time-consuming. Development of early, reliable, and reproducible selection strategies can speed up this process. Sequence characterized amplified region (SCAR) markers have been widely employed in the resistant breeding of many crops. However, to date, there have been no reports about the presence of plant disease resistance-related SCAR markers in mitochondrial genome yet, which also plays a very important role in plant defenses. In the present study, a sequence-related amplified polymorphism (SRAP) marker, a specific fragment of 829 bp, was identified. This fragment could be amplified from Foc4-susceptible but not from the resistant cultivars. It was located in banana mitochondrial genome and mapped near the putative cytochrome c biogenesis ccmB-like mitochondrial protein. This fragment was then successfully converted into a SCAR marker, namely Mito-Foc-S001, which was found to be able to discriminate the resistance from susceptibility to Fusarium wilt disease of bananas with the discriminatory power of the new mark being 96.88%. Thus, this marker can be used in banana (Musa AAA Cavendish) breeding for Fusarium wilt disease resistance.