A study of five mechanically transmissable cherry virus isolates with herbacous hosts

Josephus Antonius Johannes Marie Hoes
Five virus isolates RS 2, RS 25, RS 26, RS 28 and RS 29, were transmitted by juice-inoculation technique from sour and sweet cherry trees to cucumber. Four isolates were obtained from trees growing in the Kootenay cherry district of British Columbia. Another one was isolated from a tree growing in the coastal area of this province. Viruses known to occur in the source trees are Necrotic Ring Spot Virus, Sour Cherry Yellows Virus, Twisted Leaf Virus and Little Cherry Virus. The relationship and
more » ... he complexity of the virus isolates was studied with herbaceous hosts, using a mechanical transmission technique. Pincherry (Prunus pennsylvanica L.) was inoculated by the same technique as a means for provisional identification of the virus isolates. The cucumber syndrome of isolate RS 25 was very mild, that of isolate RS 2 mild, that of isolate RS 29 was of medium severity and those of isolates RS 26 and RS 28 were very severe. Inoculates RS 2 and RS 29 varied greatly in symptom expression on cucumber, whereas the symptom expression of the other isolates was less variable. Isolate RS 29 was characterized by symptomless systemic infection of Nemesia sp.. var. Triumph. Isolates RS 26 and RS 28 both infected Petunia hybr., var. Blue Bee, without expressing symptoms, whereas the other isolates did not infect this species. Other host species too carried the isolates without expressing symptoms, whereas symptoms were produced on cucurbit hosts. Isolates RS 2, RS 26, RS 28 and RS 29 appeared to consist of more than one virus. Strains of a virus P occur in all isolates and isolate RS 25 itself is also a strain of this virus. All five strains of virus P express similar very mild symptoms on cucumber, whereas a characteristic severe savoying type of symptom is produced on squash (var. Table Queen). Species susceptible to virus P are cucumber, pincherry, squash, sweet pea, tobacco (under conditions of long day) and other species. Lathyrus odoratus L. and Lens culinaris Medic. are species useful in separating virus P from t [...]
doi:10.14288/1.0106070 fatcat:blzfo3ivefhmxdltv6zxrgwrsq