Garlic virus complex reinfection of garlic virus free plants and plants with Allexivirus isolates

PEROTTO, MC,; CAFRUNE EE,; CONCI VC

Dronten Holanda

Simposio; . 5th International ISHS Symposium on Edible Alliaceae (ISEA); 2007

Due to the vegetative propagation of garlic, all the plants are infected by a complex of different viruses. In the process of virus elimination, plants are obtained that are free of all viruses but others conserve some. Previous works have demonstrated that virus-free plants yield up to 216% more than chronically virus-complex-infected plants. Differences in production between virus-free and chronically virus-infected plants remain for several growth cycles, even though a high percentage of field reinfection occurs. It is not known up to the present what happens to the plants that have been cleaned of only some viruses. The Garlic virus A (GarV-A) isolate causes losses ranging from 32 to 14% in bulb weight; on the other hand, the Garlic virus C (GarV-C) isolate causes mild or no damage to garlic yield (no significant differences with virus-free plants were observed in most of the trials). The objective of this work was to determine the yield loss of Allexivirus isolates exposed to natural field reinfection during four growth cycles. At the beginning of the assays, virus-free plants (VF), GarV-A isolate plants (A), GarV-C isolate plants (C), and viral-complex plants were (VC) employed. After the first cycle, a high percentage of virus-complex reinfection was observed in all treatments. At the end of the first growth cycle, the bulb weight of VF, C and A (137, 116 and 96% respectively) was significantly superior to VC plants. After the fourth year, non-significant differences were detected between VC, C and A, whereas the yield of VF was significantly higher than VC (22%). The results show that plants infected with at least one Allexivirus, and exposed to natural infections with other viruses, reduced the yield faster than those that were cleaned of all viruses (VF plants).