The purpose of this study was to evaluate the effect of cross direction and cultivars on interspecific hybridization between Vaccinium corymbosum (4x) and Vaccinium virgatum (6x). Totally 99 reciprocal interspecific crosses were made by using ten cultivars of V. corymbosum and five cultivars of V. virgatum. Percent fruit set, number of developed seeds per berry, germination rate and number of seedlings per flower were evaluated. The progeny seedlings were obtained from 65% of all cross combinations, and more than 99% of the seedlings were revealed to be pentaploid hybrids by flow cytometric analysis. In the comparison of crossability between interspecific reciprocal crossing, 4x × 6x crosses showed 2.9 times higher rate of mean fruit set (67%) and 3.3 times higher rate of number of seeds per berry (6.2) than the opposite crosses (6x × 4x). However, the average germination rate (38%) of the 6x × 4x crosses was 1.7 times higher than that of 4x × 6x crosses. Consequently, average number of seedlings per flower (0.96) in 4x × 6x was 3.8 times higher than that in the opposite crosses. According to the number of seedlings per flower significant difference in the crossability was found among the cultivars in V. corymbosum in the reciprocal crosses with V. virgatum, whereas no such significant difference was observed in V. virgatum.

Blueberries are in high demand worldwide because of their taste and functional components. However, the shelf life of blueberries is short owing to their perishability and rapid quality deterioration. Therefore, a sterilization technology must be developed that can extend the shelf life of blueberries while maintaining their appearance and taste. As such, we verified the effectiveness of three pre-storage sterilization treatments (UV-C, ozone gas, and ozone water) using mercury-free excimer UV lamps that did not adversely affect the environment. We then created a device that continuously treated blueberries with approximately 2.57 ppm of ozone gas to ensure sterilization during the storage period, and we verified the effectiveness of the device. We found that the pre-storage ozone treatment reduced the number of fungi on the blueberry surface without adversely affecting fruit quality. The continuous ozone treatment suppressed the decrease in anthocyanin content, further reduced the number of fungi on the fruit surface and maintained fruit appearance for a longer period compared with the control. This suggests that continuous low-concentration ozone treatment suppresses the decay and extends the storage period of blueberries intended for raw consumption.

Aralia cordata is called “Udo” and is one of the famous herbaceous perennial plants found in Korea, China, and Japan. In Japan, aerial parts of A. cordata have been consumed. Furthermore, its rhizome and root are utilized as crude drugs known as “dokukatsu” and “wakyoukatsu”, respectively. A. cordata is cultivated as a vegetable in many places in Japan, and one of the production areas is Tokyo. A. cordata made in Tokyo is known as a high-quality “Udo” product (aerial part) using a unique cultivation method, known as “Udo muro”. “Udo muro” blocks light and maintains optimal temperature and humidity throughout the year, facilitating the soft cultivation of udo. However, the roots of A. cordata cultivated in Tokyo are all discarded. Thus, the utilization of the A. cordata root cultivated in Tokyo might lead to sustainability and income improvement for farmers. In this study, we investigated the effect of “Udo muro” with or without cultivation and drying temperature on chlorogenic acid (CA) contents in A. cordata root and compared it with A. cordata produced in other areas (“wakyoukatsu”) by a quantitative analysis of the CA content using high-performance liquid chromatography. The results indicate that the CA content of the roots of A. cordata grown in Tokyo was higher than those grown in other areas. Furthermore, the usefulness of A. cordata root was evaluated using inhibitory activity tests such as nitric oxide production and melanin production using Raw264.7 and B16F10 cell lines, respectively.