Climate change caused by global warming, is predicted to have severe consequences for ecosystems and economic sectors. In the agricultural industry, it is predicted that there will be decreased crop yields resulting from shifting planting seasons, as well as higher temperature and water stress which significantly reduce crop productivity. Kimchi cabbage, a cold-loving plant, is particularly vulnerable to high-temperature stress which can lead to stunted growth, increased susceptibility to pests like soft rot, reduced yield, and lower quality that will negatively impact the Kimchi cabbage market. Kimchi cabbage can be cultivated in highland regions with low summer temperatures and reduced pest occurrence, but rising temperatures and water stress are expected to increase pest pressure, resulting in a rapid decrease in the potential cultivation area of Kimchi cabbage. Currently, research is being conducted around the world to identify physiological mechanisms of heat tolerance at the molecular level, selection of heat-tolerant material, and studies on cellular responses of plants under high-temperature conditions. Despite numerous studies on physiological and biochemical responses of Brassica crops to high temperatures, there is a need to develop heat-tolerant Kimchi cabbage cultivars that can adapt to rapidly changing climates, new strategies for pest control under high-temperature conditions, and mitigation measures to ensure stable cultivation and production.

Paprika (Capsicum annuum) cannot grow or set fruit in temperatures that are higher than the optimal level. This study assesses the characteristics of 52 paprika accessions introduced from the agrobiodiversity center and the world vegetable center during a high temperature period in order to develop heat tolerant lines. As a result of controlling the temperature in two greenhouses by side ventilation and fogging system, the average daily temperature of the high temperature regime was 34.3℃, which was 2.4℃ higher than that of the normal temperature regime. Plant height, stem diameter, fruit set, fruit weight, fruit shape, pericarp thickness, soluble sugar content, yield, and marketable fruit development rate were all investigated as vegetative and reproductive growth-related parameters. Plant height, fruit weight, pericarp thickness, and yield were all reduced during high temperature treatment. Six germplasm lines (T12, T15, T26, T29, T32, and T36) were selected as high-temperature tolerant lines based on these parameters. The selected lines will be used to breed heat-tolerant cultivars as well as crossbreeding for genetic analysis.

‘Sunmyoung’ is a high-yielding variety that is resistant to damage from lodging and high temperatures. Out of the 30 lines collected from a farmhouse in Yeoju in 2001, individual plants of ‘Sunmyoung’ were selected from a testing plot with artificial high-temperature stress and were further bred using the pure line separation breeding method. Preliminary and advanced yield trials were conducted in Suwon and Yeoju from 2005-2013, and regional adaptability trials were conducted in Yeoju and Anseong from 2014-2016. The rates of high-temperature stress for two- and three-year old ‘Sunmyoung’ were lower than those of the ‘Sunil’ variety by 46.2% and 34.1%, respectively. The length of the stem and small leaflets of Sunmyoung were 6.2 cm and 5.1 cm shorter than those of Sunil, and the width of the leaflets was shorter than that of Sunil by 3.9 cm-indicating a higher resistance of ‘Sunmyoung’ against lodging damage. In the regional adaptability test, the yield of Sunmyoung was 523 kg/10a, which was 5% higher than that of ‘Sunil’ (498 kg/10a). The content of ginsenoside in ‘Sunmyoung’ was 19.2 mg/g, which was lower than that of ‘Sunil’ (22.38 mg/g). Since ‘Sunmyoung’ is more resistant to high temperature stress (than ‘Sunil’), lodging stress, Rhizoctonia solani, and Alternaria panax leaf spot, and has a decent production stability with higher yields, it is expected to contribute towards the quality improvement of raw materials in ginseng production (Registration No. 7495).