Plant virus causing variegation in Camellia
Variegation in Camellia japonica flowers, so called “Fuiri” in Japanese, is identified as a white pattern in a red background. The margin of the pigmented area is unclear. This condition could be caused by a plant virus because the symptom can be transmitted to other individuals through grafting. But, until now, a causal virus had not been associated with the “Fuiri” symptoms. Our objective was to determine if this variegation was caused by a plant virus. We performed a bioassay and an isolation of double-stranded RNA (dsRNA). Sap inoculation on Nicotiana benthamiana is a rapid and efficient way to diagnose virus presence. Seven variegated Camellia cultivars were examined. Samples of two cultivars, ‘Hagoromo’ and ‘Kumagai’, induced chlorosis and necrotic spots in the indicator; another cultivar, ‘Shokko-nishiki’, induced necrotic spots and stunt. These different symptoms likely indicated that two or more viruses were present in these Camellia cultivars. Many plant viruses are known to produce dsRNA during the process of replication. We extracted dsRNA from the N. benthamiana inoculated by variegated ‘Shokko-nishiki’ using dsRNA binding protein. A dsRNA bigger than 1.5 kbp was obtained. These results indicated the existence of plant viruses in these variegated Camellia cultivars. Our RNA-Seq analysis is ongoing to identify the candidate virus from this sample.
Kento Terada won the ISHS Young Minds Award for the best poster presentation at the the IV International Symposium on Woody Ornamentals of the Temperate Zone, which was held virtually in Italy in March 2021.
Kento Terada, Botanical Gardens, Graduate School of Science, Osaka City University, Osaka 576-0004, Japan, e-mail: firstname.lastname@example.org
The article is available in Chronica Horticulturae