|BAI, I - AG & AGRI-FOOD CANADA
Submitted to: Environmental and Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2003
Publication Date: 11/5/2003
Citation: Bai, I., Tischler, C.R., Booth, D.T., Taylor, E.M. 2003. Variations in germination and grain quality within a rust resistant common wheat germplasm as affected by parental CO2 conditions. Environmental and Experimental Botany. 50:159-168.
Interpretive Summary: The concentration of carbon dioxide in the atmosphere has increased in recent years, and is expected to increase considerably in the next 100 years. We grew six varieties of wheat in greenhouses with atmospheres at normal carbon dioxide levels and at twice and three times normal carbon dioxide levels. We harvested seed from plants in these different atmospheres when the seed was mature, and determined grain yield per plant. We also analyzed the seed for percent germination and concentrations of carbon, nitrogen, and various mineral elements. Grain yield was increased by increasing carbon dioxide levels for most of the varieties, although one variety had a decreased yield at three times normal carbon dioxide level. Germination of the seed was not changed by the carbon dioxide environment in which the seed was produced. Concentration of some minerals were lower in seed produced at increased carbon dioxide for some of the varieties, although all the varieties tended to behave differently. These results indicate that the performance of one variety in an elevated carbon dioxide environment cannot be used to predict the behavior of other varieties. Also, plant breeders may be able to select for plants which exhibit increased yield in response to increased carbon dioxide concentration, and thereby increase agricultural yields of crops as carbon dioxide concentrations in the atmosphere go up.
Technical Abstract: Environmental conditions during plant growth and seed maturation influence seed quality and germinability. Elevated CO2 concentration can be considered a parental condition. Studies on the effect of parental CO2 condition on seed quality and germinability are limited, particularly for intra-population variations. Therefore, several lines of spring wheat (Triticum aestivum L. cv. AZ-MSFERS-82RR) grown under three CO2 concentrations were studied to determine the intra-population variation in seed germinability and grain quality, and the relationship between grain quality and germinability. Germination percentage was near 100% for all treatments, but different patterns in germination rate were found among entries: 1. both 700 and 1000 ppm CO2 increased germination rate, 2. both 700 and 1000 ppm CO2 reduced seed germination rate, and 3. germination rate was reduced by 700 but not 1000 ppm CO2. These variations were apparently entry-related, indicating the existence of intra-population variation in the response of germination rate to parental CO2 conditions. Chemical constituents responded to increasing CO2 concentration differently among entries, but the C/N ratio was similar among CO2 treatments. A negative correlation between C content and germination rate was found. Because elevated CO2 parental conditions may affect both seedling establishment and grain quality of crops, intra-population variations in the response of seed germinability and grain quality to CO2 conditions should be considered in future breeding efforts.