Comparison of anthocyanin distribution in berries of Haskap (Lonicera caerulea subsp. edulis (Turcz. ex. Herder) Hultén), Miyama-uguisukagura (Lonicera gracilipes Miq.), and their interspecific hybrid using imaging mass spectrometry.

Haskap (Lonicera caerulea subsp. edulis), a shrub with violet-blue fruits, is distributed mainly in Hokkaido, Japan. Miyama-uguisukagura (Lonicera gracilipes), a species related to Haskap, produces red fruits. Interspecific hybridization of Miyama-uguisukagura and Haskap was performed to introduce novel characteristics in the resulting hybrids. The shape and color of the interspecific hybrid fruits differed from those of the parent fruits. A comparison of anthocyanin distribution among these three fruit types by imaging mass spectrometry (IMS) revealed the presence of five different anthocyanins. The average cyanidin 3,5-diglucoside and peonidin 3,5-diglucoside intensities in the interspecific hybrid fruit were higher than those of the parent fruits, whereas the average pelargonidin 3-glucoside, cyanidin 3-glucoside, and peonidin 3-glucoside intensities were the highest in Haskap. All anthocyanins were mainly accumulated in the inner and outer skins of Haskap and interspecific hybrid fruits, and in the skin of Miyama-uguisukagura fruits. The order of signal intensities of all anthocyanins among the three fruits was unchanged in different regions. Additionally, a comparison of IMS and LC/MS data from our previous study confirmed the possibility of comparing multiple fruits in the same plate by IMS. Thus, we elucidated anthocyanin distribution patterns of the interspecific hybrid and parent fruits by IMS.