Virus eradication in lily by combination of in vitro culture techniques.

CHINESTRA, CAROLINA; MARINANGELI PABLO; CURVETTO, NÉSTOR

Pescia

Simposio; 2nd International Symposium on Genus Lilium; 2010

International Society for Horticultural Science

In order to eradicate Lily symptomless virus (LSV), Lily mottle virus (LMoV), and Cucumber mosaic virus (CMV) in lily, chemotherapy and thermotherapy were employed in vitro with or without meristem tip culture. Bulbs of Lilium longiflorum × Oriental hybrid ‘Triumphator’ positive for the three viruses by DAS-ELISA (double sandwich antibody-enzyme linked immunosorbent assay) were used as explants source for in vitro culture. After two multiplication cycles in darkness, microscales were divided longitudinally and cultivated in vitro at 25°C or 35°C (thermotherapy) during one month on a MS medium supplemented with 0.03 mg L-1 ANA with or without 20 µM ribavirin (Virazole®). Half of the regenerated bulbs of each treatment (over 52) were selected at random and planted ex vitro and the leaves were tested for the viruses by DAS-ELISA after two and six months of ex vitro culture. The remaining bulbs were used for meristem tip culture on MS medium at 25ºC and 16 h photoperiod (RFA 48 umol cm-2 s-1). After six months of in vitro culture, bulblets were planted ex vitro and leaves were screened for viruses after two and six months in greenhouse. Thermotherapy caused browning of microscales and death. Microscales at 25°C showed a high bulblet regeneration proportion (97%). The 28.9 % and 34.6% of bulbs obtained at 25ºC, with and without meristem tip culture, respectively, presented LMoV after two months of ex vitro cultivation. After six months, the percentages increased to 33.3% and 48.7%, respectively. LSV was detected in 4.4% and 67.3% of bulbs with and without meristem tip culture, respectively, after two months of ex vitro cultivation. After six months the percentages were 3% and 71.8%, respectively. CMV was not detected in any treatment. No significant differences between treatments with and without ribavirin were found (p> 0.05). Meristem tip culture increases the efficiency of virus eradication in lilies. This process depends not only on treatment but also in the virus involved. Further studies to evaluate different thermotherapy and chemotherapy treatments are being implemented.