Studies on the Carotenoid Constitution of Various Tomato Strains

Part III. Carotenoid contents of double recessives hybrid strains separated from the cross of Beta orange and Yellow, Tangerine and Apricot strains

Abstract

Carotenoid contents and coloring were observed as to the double recessives genotype tomatoes, one of F₂ hybrids of Beta Orange strain crossed with Yellow, Tangerine and Apricot strains.
Following nesults were obtained;
(1) Gene r controls production of total carotenoid. The function is, r⁺r⁺>r⁺r>rr, and in rr only a small amount of carotenoid is produced. Therefore, in the double recessives genotype rrBB, β-carotene was found in small amount, approximately 1.0-1.5μg/g.
(2) Gene t controls production of poly-cis form carotenoid. But only tt produced poly-cis form neurosporene and lycopene, though t⁺t⁺ and t⁺t did all-trans form lycone. Therefore, in the double recessives genotype ttBB, changing to β-carotene was as small as 15-20μg/g.
(3) Gene at controls carotenoid production, and the interruptive function is; atat>at⁺at>at⁺at⁺. But gene at is hardly effected production of β-carotene. In the double recessives genotype atatBB, total carotenoid content was as small as 10-15μg/g.