Climate change has had a significant impact on apple phenology and fruit quality worldwide. Similarly, a decline in fruit quality has been observed in major apple-producing areas of Korea. It is predicted that the ideal cultivation areas for apples would need to shift toward higher latitudes due to these changes. Hence, the objective of this study was to assess the influence of climate change on apple cultivated in a higher-latitude region. To achieve this goal, we investigated the flowering and harvest times of apples. Additionally, we measured fruit weight, soluble solid content, and titratable acidity over a period of 20 years in a higher-latitude region in Korea. Subsequently, we examined the relationship between temperature, phenology, and fruit quality through the use of linear regression and correlation analysis methods. The 20-year meteorological data revealed a consistent rise in temperatures. Consistent with this trend, we found a significant advancement in budbreak and flowering dates for the two major apple cultivars grown in a higher latitude in Korea. Furthermore, the increase in temperatures has positively influenced fruit quality, indicating that climate change has an impact not only on phenology, but also on the quality of apples in Korea. Considering the projected gradual increase in temperature, our findings strongly support that higher-latitude regions in Korea have the potential to become optimal locations for apple cultivation.

This study evaluated unripe fruits of ten apple cultivars removed during fruit thinning for their antioxidant activity and mineral content. The unripe fruits were collected from Chuncheon and Jeongseon located at Gangwon-Do of Korea. Antioxidant activities such as total phenolic content (TPC), total flavonoid content (TFC), DPPH (2,2-diphenyl-1-picrylhydrazyl) activity, FRAP (Ferric reducing antioxidant power), vitamin C and mineral contents were measured. In the unripe fruits obtained from Chuncheon and Jeongseon, TPC was in the range 8.97–81.4 and 7.11–42.15 mg GAE/g, TFC was in the range 9.38–33.81 and 6.83–19.24 mg QE/g, DPPH was in the range 27.17–82.58 and 29.73–73.24, FRAP was in the range 33.54–371.12 and 26.76–185.69 µM trolox /g, and Vitamin C was in the range 1.1–4.9 and 1.1–2.8 mg/AA/g, respectively. Among the cultivars tested, ‘Hongro’ and ‘Honggeum’ had consistently highest antioxidant activity, while ‘Summer King,’ ‘Tsugaru,’ and ‘Arisoo’ had the lowest value. ‘Picnic’ had the highest mineral contents expect P and K in Joengsoen, while ‘Summer King’ and ‘Tsugaru’ had the lowest value in both locations. These differences could be due to the genetic characteristics and/or their growth environments. These results could provide information to help with better utilization of thinned unripe fruits of apples in Korea.

The incidence of grapevine virus infections in Korean vineyards was investigated from July to October, 2020. A total of 177 petiole samples were collected from two or three different cultivars in each of four different regions; these were examined by reverse transcription-polymerase chain reaction assay for the presence of 14 major viruses. The overall occurrence of grapevine viruses was 91.0%, and the level of incidence was high irrespective of region or cultivar. The predominant viruses were grapevine leafroll-associated virus 3 (80.2%), grapevine fleck virus (70.6%), and grapevine rupestris stem pitting-associated virus (49.2%). Most grapevines were infected with multiple viruses, suggesting that Korean vineyards are likely to suffer economic losses resulting from viral diseases. This is the first extensive survey performed in Korea to observe the outbreak status of diverse grapevine viruses; surveys of this type can provide important information for the management of grapevine viruses in Korea.

The storage capacity of ‘Cheonghyang’ grapes, a promising grape cultivar developed in South Korea, is a critical factor affecting their commercial viability. This study investigates the impact of salicylic acid (SA) treatment on the storage capacity of ‘Cheonghyang’ grapes. The effects of SA treatment at different concentrations were assessed by comparing fruit characteristics and enzyme activity related to shelf life after two and four weeks of cold storage in comparison with an untreated control group. The findings reveal that SA-treated grapes exhibited reduced water loss and improved firmness, leading to a lower occurrence of unmarketable berries. Furthermore, enzymes involved in pectin degradation, such as pectate lyase and polygalacturonase, were reduced in the SA-treated group, while antioxidant activity-related enzymes, including catalase, peroxidase and superoxide dismutase, were more active than in the control group. The most effective control of enzyme activities was observed at an SA concentration of 2 mM, which demonstrated the least decline in fruit quality among the tested SA concentrations in this study. These results indicate that SA is a highly effective substance for maintaining the storability of ‘Cheonghyang’ grapes under conditions of low-temperature storage after harvest.

Consumer demand for seedless grape with high quality and large berry has been increasing. Breeding of hypotetraploid grape was suggested as one of promising methods to satisfy it, but low frequency of hypotetraploid occurrence and low seed germination by abortive embryo were indicated as the major problem to hamper the development of hypotetraploid grape. Hence, this study was carried out to evaluate the basic efficiency of in ovulo embryo culture after the cross between hypotetraploid (‘Hanareum’) and tetraploid (‘Honey Black’ and ‘Kyoho’) grape cultivars on the establishment of hypotetraploid grapes. Embryos and plantlets were hardly obtained in ovules cultured at six after the cross pollination (WAP), but ovules inoculated at 10 WAP produced more embryos as well as plantlets regardless of cross combination. Furthermore, we found that embryo formation was not affected by the basal media in ovules cultured at six WAP, but utilization of specific medium can be more beneficial for embryo formation when ovules were cultured at 10 WAP. A total of 17 plants were obtained from ovules cultured at 10 WAP, and above 50% of plants were identified as hypotetraploid grapes. These results indicate that in vitro embryo rescue after cross pollination between hypotetraploid and tetraploid grape can enhance the efficiency for the breeding of hypotetraploid grapes.

Motherwort (Leonurus japonicus Houtt) is an important medicinal plant known for its excellent antioxidant properties. Nonetheless, in South Korea, its availability remains limited due to the challenge of low seed germination rates, affecting field production. To tackle this problem, it is imperative to focus on controlled production methods. In our study, we conducted experiments in a laboratory setting, employing various combinations of light-emitting diode (LED) lights to cultivate motherwort. The influence of LED light quality on seed germination, initial growth, and functionality of motherwort is evaluated. The germination rate of motherwort ranged from 36.1±7.35 to 75.0±1.60, and the highest value was observed in the red LED 100 treatment. The mean shoot length also varied depending on LED light quality. The longest shoot length (3.45±0.13g) was obtained in the red LED 100 treatment. The highest shoot weight (0.266±0.011cm) and root weight (0.051±0.008cm) were obtained in the red LED 70 and blue LED 30 mixed treatment. The total phenolic content of the motherwort sprout ranged from 2.50±0.30mg GAE/g to 3.01±0.09mg GAE/g, with the highest value from the white LED (control) treatment, but no significant differences were observed among the treatments. The red LED 30 and blue LED 70 mixed treatment showed the highest total flavonoid content (11.62±0.79mg QE/g) and DPPH radical scavenging activity (57.64±2.95). The red LED 70 and blue LED 30 mixed treatment had a similar level of DPPH scavenging activity as the control, and there was no positive or negative effect on the functionality of motherwort sprout. Overall, the results suggest that the red LED 70 and blue LED 30 mixed treatment can be effectively used to increase productivity in motherwort without decreasing its important quality.