Pollen and seed transmission of coconut cadang-cadang viroid in Cocos nucifera
Studies carried out in the Philippines have shown that coconut cadang-cadang viroid (EPPO A1 quarantine pest) could be transmitted through seednuts and pollen of coconut palms (Cocos nucifera). F1 progenies of healthy and infected parents pollinated with diseased pollen contained the viroid and showed typical symptoms of the disease, 6 years after germination. In addition, coconut cadang-cadang viroid was detected in seedlings, embryos and plantlets grown in vitro originating from naturally infected palms. The authors concluded that this was the first evidence of cadang-cadang disease transmission to progenies of infected palms, although at a low level, or through seeds of healthy mother palms fertilized with diseased pollen. However, they felt that other means of transmission are probably involved considering the large epidemics which have occurred, and several other epidemiological observations.
Sources
Pacumbaba, E.P.; Zelazny, B., Orense, J.C.; Rillo, E.P. (1994) Evidence for pollen and seed transmission of coconut cadang-cadang viroid in Cocos nucifera.
Journal of Phytopathology, 142 (1), 37-42.