A newly-approved project will evaluate Philippine mango varieties and strains for resistance to stem-end rot and scab diseases.
The Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology (DOST-PCAARRD) recently launched the three-year project, “Fruit Quality Improvement in ‘Carabao’ Mango through Quantitative Trait Loci (QTL) Identification for Scab and Stem-end Rot Resistance by Genotyping-By-Sequencing (GBS) and Genome Wide Association Studies (GWAS).”
Dr. Edward A. Barlaan of the University of Southern Mindanao (USM) leads the project, which will also develop molecular markers and establish a GBS-generated sequence database associated with resistance to the said diseases.
Stem-end rot, caused by fungi Cytosphaera mangiferae, Dothiorella dominicana, Botryodiplodia theobromae and Lasiodiplodia theobromae, is a major problem limiting the storage and shelf life of mango fruits. Dark, circular lesions develop slowly from the stem end as fruit ripens after harvest.
Mango scab, on the other hand, is caused by the fungal pathogen, Elsinoë mangiferae. The disease starts as small dark brown or gray spots on the underside of leaves or fruit, which enlarges and darkens over time. It affects young and mature fruits, twigs, leaves, and blossom spikes. Severely affected fruits fall off while new shoots may defoliate.
These issues prompted the project team to identify sources of resistance in mango germplasm that can be used in ‘Carabao’ mango improvement.
An online inception meeting was held on August 18, 2020 to formally launch the implementation of the project.