Effect of carbon dioxide on seed transmission of Lettuce mosaic virus

Carbon dioxide as the cause of glasshouse effect and global warming is the current dilemma of human societies. It is well know that CO2 is one of the principle requirements of plant growth and it promotes seed production. As to the seed transmission rate of virus under increased CO2 level there was no work prior to this study. In this study, seeds harvested from lettuce plants that were grown under ambient (375 ppmv) and elevated (E) CO2 (750 ppmv) and grown from Lettuce mosaic virus (LMV)-infected seeds or sap-inoculated were tested to find out if ECO2 affects the seed transmission rate. Accordingly, two seed-lot samples (each 25 seeds) from each of the treatments were germinated on wet filter paper in Petri dishes and four-day old seedlings were subjected to double antibody sandwich enzyme-linked immunosorbet assay (DAS-ELISA) by the use of "home-made" conjugate with appropriate controls. The outcome from this study showed that the transmission rate in seeds from plants grown from infected seeds under ECO2 was higher (8.5%) compared to that from plants grown under ambient CO2 (6.8%). Likewise, the rate in seeds from sap-inoculated plant under ECO2 was higher (4.17%) than that from plants grown under ambient CO2 (4%). In addition, the transmission rates in plants grown from infected seeds were higher (8.5% or 6.8%) than that in seeds from the inoculated plants (4% or 4.17%).