Molecular markers to aid in ‘Carabao’ mango improvement

‘Carabao’ mango is the Philippines’ export variety known as ‘Manila Super’ mango in the international market. Its export potential is, however, hampered by industry problems such as low yield and quality due to pests and diseases, which include fruit fly and anthracnose. There is also a growing preference for mango fruits with red skin in many export destinations such as Europe and America.

Anthracnose is caused by Colletotrichum gloeosporioides, a fungal pathogen that affects pre- and postharvest quality. Damage is characterized by small black circular lesions that enlarge and coalesce as the fruits ripen. Fruit fly (Bactrocera dorsalis), on the other hand, is a major insect pest infesting mango at fruiting stage. Fruit fly larvae feed on the flesh. Infestation occurs as puncture marks and black (or brown) injuries on the flesh.

The University of the Philippines Los Baños (UPLB) took the initiative to look for possible resistance against these pests through a biotechnology project titled, Identification of Molecular Markers Associated with Red Blush, Thick Peel, and Resistance to Anthracnose and Fruit Fly under the Enhancing Competitiveness of Philippine ‘Carabao’ Mango through Varietal Improvement Program. The said project was funded by the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology (DOST-PCAARRD), as part of its Industry Strategic S&T Program (ISP) for mango.

The importance of biotechnology as a tool in crop improvement has been recognized in recent years. Specifically, selection through the use of molecular markers hastens crop breeding. Through the abovementioned project, molecular markers associated with the target traits – red blush, thick peel, and resistance to anthracnose and fruit fly, have been generated by the application of Genotyping by sequencing (GBS) technology. The said markers can be utilized in marker-aided selection in the future as part of efforts on mango breeding.