The effects of atmospheric carbon dioxide on the development of the Meloidogyne nematode and Meloidogyne induced giant cells in Vicia faba

Both temperature and atmospheric carbon dioxide, key variables that affect plant growth, have changed in the recent past and are predicted to change further in the future. Current atmospheric carbon dioxide levels of 360 ppm (parts per million) are 30% greater than those in 1750 and are increasing at approximately 1.5 ppm/year. It is estimated that by the year 2100, carbon dioxide levels will range anywhere from 540 to 970 ppm. The United Nations has estimated that increased carbon dioxide levels could raise global temperatures from 1.4 to 5.8°C by 2100 A. D.; Few studies have attempted to quantify the effects of elevated carbon dioxide on plant pathogenic nematodes. We have examined the effects of elevated atmospheric carbon dioxide on the multi-nucleate giant cells induced by the root-knot nematode Meloidogyne arenaria, and egg production on the host plant Vicia faba. When grown at CO₂ levels twice ambient, giant cells have significantly more nuclei than when grown at ambient CO₂ levels. Further, these nuclei accumulate DNA at a faster rate, although they do not reach higher overall contents, when grown at elevated CO₂ levels. Finally, egg production is significantly greater when the host plants are grown at elevated CO₂ levels.