Lavender (Lavandula angustifolia L.) cultivated in a hydroponic system in Ethiopia was found infected with Meloidogyne javanica

Plants grown without soil are believed to be less affected by soilborne diseases. However, in a commercial greenhouse in Ethiopia's Rift valley, Lavender plants grown in hydroponic showed signs of severe stunting and galled roots. To identify the cause of the problem, root samples were taken. From these samples, single egg masses were obtained and used as inoculum for tomato cv. Moneymaker seedlings. The resulting seedlings were grown to produce a pure culture. DNA was extracted from second-stage juveniles (J2) from sixteen isolates derived from pure cultures and amplified the 28S rRNA and NADH dehydrogenase subunit 5 (Nad5) region of the mtDNA. The 28S rRNA and Nad5 were sequenced for two and five randomly selected isolates. A BLAST search of 28S rRNA sequences at NCBI showed a 98.34% sequence homology with known sequences of Meloidogyne javanica isolates. Moreover, Nad5 gene analysis, female perennial pattern, and the phylogenetic trees further confirmed the correct identification of this species. This is the first report of a nematode infecting plants growing in a hydroponic greenhouse in Ethiopia. Therefore, isolating any potential contaminants of the potting media for future lavender production are important.