Submitted to: Lettuce Workshop and Leafy Vegetable International Conference Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 3/16/2004
Publication Date: 8/28/2004
Citation: Mou, B. 2004. Genetic variation of carotenoid content in lettuce. Lettuce Workshop and Leafy Vegetable 17th International Conference. August 28-31. 2004. Montral, Quebec, Canada. No page numbers. Interpretive Summary: N/A
Technical Abstract: There is increasing medical evidence for the health benefits derived from dietary intake of carotenoid antioxidants, such as ß-carotene and lutein. Efforts by public health organizations and produce industry to increase the consumption of fruits and vegetables have met limited success due to dietary habits and cultural reasons. Enhancing the nutritional levels of vegetables would improve the nutrient intake without requiring an increase in consumption. Although lettuce (Lactuca sativa) is a staple food, it (especially the crisphead type) is a poor source of vitamins and minerals. A breeding program to improve the nutritional quality of lettuce must start with an assessment of the existing genetic variation. Little is known about varietal differences, as available nutrient data were mostly obtained by analyzing samples from supermarkets. To assess the genetic variability in carotenoid content, fifty-two lettuce genotypes including crisphead, leaf, romaine, butterhead, wild species, Latin, primitive, and stem lettuces were planted at the USDA field in Salinas in the summer and fall of 2003 with four replications. Duplicate samples from each plot were analyzed for moisture, chlorophyll (a and b), ß-carotene, and lutein contents by high performance liquid chromatography (HPLC). Primitive, L. serriola, L. saligna, and L. virosa accessions had higher ß-carotene and lutein contents than cultivated lettuces. There was significant genetic variation in carotenoid content within crisphead, butterhead, green leaf, red leaf, and romaine types of lettuce. ß-carotene and lutein contents were highly correlated, suggesting that their levels could be enhanced simultaneously. ß-carotene and lutein contents were both highly correlated with chlorophyll a, chlorophyll b, and total chlorophyll contents, suggesting that carotenoid content could be selected indirectly through chlorophyll or color measurement. These results suggest that genetic improvement of carotenoid levels in lettuce is feasible.