First report of Apple stem grooving virus, Apple stem pitting virus, and Apple chlorotic leaf spot virus in apple trees from Chencha, Ethiopia.
Apple (Malus pumila) is an important fruit crop in Ethiopia. Among the viruses reported to infect apple, Apple mosaic virus (ApMV), Apple stem grooving virus (ASGV), Apple chlorotic leaf spot virus (ACLSV), and Apple stem pitting virus (ASPV) are important constraints on fruit yield and quality. To validate whether these viruses are present in Ethiopia, 30 leaf samples were collected from 10 different cultivars (CP92, Granny Smith, BR-64, Anna, Jonica, Princessa, Dorset Golden, MM106, Elstar, and Crispin) growing in the southwest part of the country in October 2015. Three different trees of each cultivar were randomly selected for collecting three different samples, and total RNA was extracted from these samples. RT-PCR results revealed that ASGV was detected in all the 10 cultivars except CP92, whereas ACLSV and ASPV were each detected in only 4 cultivars (BR-64, Anna, Princessa, and Dorset Golden). ApMV was not detected in all cultivars. Mixed infections with ASGV, ACLSV, and ASPV were detected in 4 cultivars. ELISA test was carried out, which confirmed the RT-PCR results. This is thought to be the first report of ASGV, ASPV, and ACLSV in apple trees growing in Ethiopia.