Yellow Mosaic Symptoms Induced by Y Satellite RNA of Cucumber Mosaic Virus is Regulated by a Single Incompletely Dominant Gene in WildNicotianaSpecies

Y satellite RNA (Y-satRNA) of cucumber mosaic virus (CMV) together with the helper virus induces a bright yellow symptom when inoculated on tobacco plants (Nictotiana tabacum) and develops a green mosaic symptom in N. clevelandii, while N. bigelovii exhibits a yellow symptom when inoculated with CMV-O plus Y-satRNA, even though the two wild species are very closely related to each other. N. bigelovii and N. clevelandii were crossed to analyze the symptom expression of the progeny plants. When inoculated with CMV+Y-satRNA, all the F 1 plants initially showed a faint yellow mosaic, which eventually turned into a green mosaic with traces of yellow, indicating intermediate symptoms []