Differential inheritance of pepper (capsicum annum) fruit pigments results in black to violet fruit color

Authors: Stommel, John; PUSHKO, MARIJA - Collaborator; Haynes, Kathleen; Whitaker, Bruce

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2014
Publication Date: 8/8/2014
Publication URL: http://handle.nal.usda.gov/10113/61460
Citation: Stommel, J.R., Pushko, M., Haynes, K.G., Whitaker, B.D. 2014. Differential inheritance of pepper (capsicum annum) fruit pigments results in black to violet fruit color. Plant Breeding. DOI:10.1111/PBR.12209.

Interpretive Summary: Consumer demand for fruits and vegetables with novel color and form has grown considerably and resulted in specialty markets with traditional fruits and vegetables that are grown primarily for their eating characteristics rather than for yield or shipping attributes. Additional knowledge of the genetic and biochemical basis for these new attributes is needed so that plant breeders can effectively develop new improved fruit and vegetable varieties. Utilizing the rich diversity available in pepper for fruit color, we characterized the inheritance of black to violet fruit color and identified the pigments that are responsible for these novel fruit colors. We found that multiple genes control black and violet fruit coloration. Several plant pigments were responsible for fruit color. Green chlorophylls, yellow to orange carotenoids, and violet anthocyanin pigments combined to cause black to violet coloration. These results will benefit plant breeders in developing new pepper varieties and provide valuable information for further research to identify and characterize genes that influence color in plants.

Technical Abstract: Color and appearance of fruits and vegetables are critical determinants of product quality and may afford high-value market opportunities. Exploiting the rich genetic diversity in Capsicum, we characterized the inheritance of black and violet immature fruit color and chlorophyll, carotenoid and anthocyanin pigments responsible for fruit color. In contrast with simple inheritance demonstrated for presence or absence of anthocyanin pigmentation in Capsicum fruit, but consistent with prior results demonstrating complex inheritance for anthocyanin pigmentation in Capsicum foliage, segregation for black versus violet fruit color deviated from expectations of models for simple inheritance. The primary determinant of fruit color was the concentration of the fat soluble chlorophyll and carotenoid pigments relative to anthocyanin concentration. Whereas anthocyanin concentration was 34% greater in violet fruit, chlorophyll and carotenoid concentrations were 20-fold and 4-fold greater, respectively, in black fruit relative to concentrations found in violet fruit. CIE L*a*b* color space scores were predictive of fruit color and relative pigment profiles in black and violet fruit. An additive-dominance model (m[d][h]) was sufficient to explain the variation for individual fruit pigments as well as the CIE parameter a*. Addition of additive x additive effects ([i]) to the additive-dominance model resulted in the best fit model m[d][h][i] for L* and b* color space parameters. For all pigment classes, significant additive effects contributed to the genetic variance for fruit color.