Internal CO2Concentration as a Selection Criterion for Storage Respiration Rate in Sugarbeet

摘要

AbstractRespiration is responsible for much of the sucrose loss that occurs during sugarbeet (Beta vulgansL.) storage. Genotypes with reduced storage respiration rates would provide an efficient method for reducing sucrose losses. However, the current techniques for measuring storage respiration are not adapted easily to breeding programs. Internal CO2concentration has been recommended as an efficient method for measuring the respiration rate of individual sugar‐beet roots in storage. This study examined the effectiveness of internal CO2concentration as a selection criterion for reducing respiration rate of sugarbeet during storage. Lines resulting from four cycles of divergent selection for internal CO2concentration were evaluated along with commercial hybrids and low internal CO2germplasm lines. Selection was effective in shifting internal CO2concentration. Relative differences in internal CO2concentration were consistent throughout the 3‐year study. Neither the fourth‐cycle selections for low nor the fourth‐cycle selections for high internal CO2concentration were significantly different from the original population for evolved CO2. This lack of a close relationship between internal and evolved CO2indicated that internal CO2concentration is not an effective selection criterion in a breeding