Submitted to: Journal of Heredity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2007
Publication Date: 3/1/2008
Citation: Lightbourn, G., Griesbach, R., Novotny Dura, J., Clevidence, B.A., Rao, D.D., Stommel, J.R. 2008. Effects of anthocyanin and carotenoid combinations on foliage and immature fruit color of capsicum annum l. Journal of Heredity. 99:105-111. Interpretive Summary: Color is a key component that influences a consumer’s perception of product quality. Whereas pepper fruit color is important for culinary product quality, foliar pigmentation is also an important aspect of ornamental variety appeal. Color of unripe pepper fruit varies from green and yellow to ivory, through varying shades of violet and purple to nearly black. Foliage and stem color may vary from green to varying shades of green/purple to nearly black. Color is attributed to several pigments. Included among these are the chlorophylls and anthocyanins. Anthocyanins produce blue to red colors and chlorophylls are responsible for green color. In this study, we determined the biochemical factors responsible for violet and black color in fruit and black color in leaves of pepper. Chemical and microscopic analysis of cells in fruits and leaves identified the pigments that produce the characteristic violet and black color in the varieties evaluated. High levels of anthocyanin in combination with chlorophyll produced black coloration in fruit and leaves. In comparison to black fruit, violet fruit contained similar anthocyanins, but relatively little chlorophyll. Violet and black color mutants in pepper and other plant species have provided valuable opportunities to develop new landscape and garden plants. Knowledge obtained from the characterization of these novel colors, together with a wealth of scientific information describing the production of the pigments involved, provide new opportunities for scientists to investigate the regulation of pigment biosynthesis and for plant breeders to develop new pepper varieties with novel fruit and leave color.
Technical Abstract: Shades of violet to black pigmentation in pepper (Capsicum annuum L.) is attributed to anthocyanin accumulation. HPLC analysis of violet and black fruit tissue identified a single anthocyanidin and four anthocyanins. The anthocyanidin was determined to be delphinidin. The HPLC profiles of the delphinidin glycosides for violet and black fruit were very similar. The chlorophyll concentration was more than five-fold higher in black fruit in comparison to violet fruit which contained relatively little chlorophyll. Black leaf tissue also contained a single anthocyanidin, delphinidin, but a greater number of delphinidin glycosides at relatively higher levels in comparison to violet and black fruit tissue. High concentrations of delphinidin glycosides in combination with chlorophyll produced the characteristic black pigmentation observed in fruit and leaves of selected genotypes. Anthocyanins were accumulated in the outer mesocarp of violet and black fruit and in the palisade and mesophyll cells of black leaves. Consistent with chlorophyll content of respective genotypes, chloroplast density was greater in cells of black fruit.