Cucumber green mottle mosaic virus (CGMMV) can induce hair-like tissues on genus Cucumis seeds

Distinct morphological changes were observed on surface of Cucumber green mottle mosaic virus (CGMMV) infected genus Cucumis seeds. When the infected and healthy seeds were treated with ethanol series, unusual hair-like tissues were observed on surface of infected seeds. Morphology of these tissues was studied by stereo microscopy and field emission scanning electron microscopy. The hair-like tissues were observed on surface of seed coat of infected cucumber, musk melon and oriental melon and raised from the seed coats. Such tissues were not observed on seed coat of the same treated healthy cucumber and musk melon but such tissues were found as attached to seed coat of oriental melons. The width of hair-like tissues varied depend on species of genus Cucumis seeds, 2-2.5 μm on musk melon and 9-10 μm on oriental melon and cucumber seeds. The phenomenon was re-confirmed by RT-PCR and nested PCR assays that the seeds which had hair-like tissues on their seed coats were infected by CGMMV. Therefore, this study suggests that the hair-like tissues are a unique symptom as external morphological changes of genus Cucumis seeds induced by CGMMV.