Title: Inheritance of carotenoid content in tetraploid and diploid potato clones Authors
Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 2, 2011
Publication Date: August 1, 2011
Citation: Haynes, K.G., Clevidence, B.A., Rao, D.D., Vinyard, B.T. 2011. Inheritance of carotenoid content in tetraploid and diploid potato clones. Journal of the American Society for Horticultural Science. 136:265-272. Interpretive Summary: Carotenoids are plant pigments that have important human health benefits. They also impart yellow color to fruits and vegetables. The nutritional value of potatoes, already an excellent source of carbohydrates for energy, vitamin C, potassium, fiber, and all the essential amino acids, could be improved even more by increasing their carotenoid content, and it makes sense to do so since potatoes are widely consumed. In this study we crossed wild potatoes with very high, moderate, and low carotenoid levels into commercial potatoes. We were hoping that potatoes from crosses involving the very high carotenoid parent would have higher levels of carotenoids, however, this was not the case. As long as one parent produces carotenoids, there will be high, intermediate, and low carotenoid potatoes produced from it. None of the potatoes had a carotenoid content even close to the high carotenoid exotic parent. This will make it difficult for potato breeders to develop new potato cultivars with high carotenoid levels. This information will be useful to breeders and molecular geneticists seeking to improve the carotenoid content of potatoes, nutritionists, and biochemists studying the biosynthesis of carotenoids.
Technical Abstract: Carotenoids have a wide range of human health benefits. Yellow-fleshed tetraploid potato cultivars have more than twice the concentration of carotenoids as white-fleshed cultivars. However, carotenoid concentrations in some diploid potatoes have been reported to be up to 13 times higher than in ‘Yukon Gold’, the most popular yellow-fleshed potato cultivar grown in the United States, and up to 22 times higher than in white-fleshed potatoes. The purpose of this study was to determine the feasibility of using these high carotenoid diploids to develop high carotenoid tetraploid germplasm. Three diploid clones with high, moderate, and low carotenoid levels that produced 2n pollen were crossed with a light yellow-fleshed tetraploid advanced breeding selection to determine the inheritance of carotenoid content. Thirteen to 14 progeny from these three 4x-2x families were grown in a replicated field experiment in Presque Isle, Maine for two years. Following harvest, carotenoids were extracted and quantified by HPLC. A continuous distribution of carotenoid concentration, with high and low carotenoid segregants was observed in all three families. There were no significant differences among these three families for individual or total carotenoid concentrations, however, there were significant differences among clones within families. Broad-sense heritability estimates were high for total carotenoid (0.81), lutein (0.77), zeaxanathin (0.73) and the LCY-b pathway carotenoids (0.73), moderate for neoxanthin (0.42), and low for violaxanthin (0.21) and antheraxanthin (0.13). It appears that selection for high carotenoid tetraploid germplasm can be made from within any family with at least one yellow-fleshed parent. Selections will have to be made on an individual clonal basis, rather than on a family basis.