Carotenoid and Starch Content of Near-isogenic B+B+ and BB Genotypes of Cucurbita

Abstract

Abstract The starch and carotenoid contents of the flesh of mature fruits were compared in 10 B+B+ Cucurbita accessions and their near-isogenic BB counterparts. There were significant differences among the accessions with respect to starch, total carotenoid, carotene, and xanthophyll contents. The accessions also responded differently to the substitution of B for B+. The B allele reduced the starch content only in those accessions possessing a high starch content with B+B+. B increased total carotenoids in most of the accessions. Those having the lowest carotenoid content in the presence of B+B+ were least affected by substitution of B. C. pepo cv. Fordhook Zucchini, and a breeding line derived from it, showed the greatest increase in carotenoid content after allelic substitution. The possible role of the B allele in plastid development and its use in breeding for increased carotene content in Cucurbita are discussed.