Abstract
Abstract Several genotypes of lettuce (Lactuca sativa L.), significantly differing in NO3 accumulation, were used to study the relationship between NO3-N concentration and NO3 reduction. Reduction of NO3 was investigated by measuring the in vivo nitrate reductase activity and the production of organic N. When NO3 was supplied to the in vivo assay, no relationship was found between the enzyme activity and the NO3-N concentration of the tissue, whereas this activity was positively correlated to the NO3-N concentration when NO3 was omitted during the incubation. As an indicator for the in situ NO3 reduction, organic N was determined. No relationship between NO3-N concentration and production of organic N occurred when different genotypes were compared. Nitrate-N, nitrate reductase activity, and organic N decreased with increasing age of the plants. The results suggest that accumulation of NO3 is not solely a result of a variation in reduction capacity between cultivars. Breeding for low NO3 accumulation should not be focused only on the increase of either nitrate reductase activity or production of organic N.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the American Society for Horticultural Science
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
