Novel production of β-cryptoxanthin in haskap (Lonicera caerulea subsp. edulis) hybrids: Improvement of carotenoid biosynthesis by interspecific hybridization
Ryohei Fujita, Shigeki Jin, Kotaro Matoba, Yoichiro Hoshino
Abstract
Carotenoids are important color pigments that contribute to human health. Haskap (Lonicera caerulea subsp. edulis), a shrub mainly distributed in Hokkaido, produces violet-blue berries low in carotenoid amount. We have conducted interspecific hybridization between Miyama-uguisukagura (Lonicera gracilipes var. glandulosa) and haskap to obtain interspecific hybrids for improving fruit quality. In this study, we compared four carotenoid concentrations in fruits using liquid chromatography/tandem mass spectrometry (LC/MS/MS) to reveal carotenoid accumulation changes by interspecific hybridization. β-Carotene was the main carotenoid, and the concentration in interspecific hybrids (0.49–0.77 mg/100 g FW) was higher than Miyama-uguisukagura (0.37 mg/100 g FW) and haskap (0.25–0.35 mg/100 g FW). β-Cryptoxanthin concentration was below the quantification limit in haskap strains; however, we could quantify β-cryptoxanthin in interspecific hybrids. β-Cryptoxanthin concentration in Miyama-uguisukagura fruits and the interspecific hybrid strain that contained higher β-cryptoxanthin tended to increase during maturation, although others did not increase. Our study revealed that interspecific hybridization changed carotenoid biosynthesis, increased β-carotene, and induced the conversion of β-cryptoxanthin to haskap. This study proposes a strategy to expand color variation by interspecific hybridization in fruit breeding programs and provides novel materials to analyze the “vigor” phenomenon in hybrid plants.