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.

In Asia, where climate change is increasing the damage caused by cold stress, it is crucial to cultivate varieties with enhanced cold tolerance. In this study, the Tongil variety ‘Hanareum2’ was crossed with the Japonica variety ‘Unkwang’ to improve plant growth ability at low temperatures during the seedling stage. This led to the development of 234 recombinant inbred line (RIL) populations, and a linkage map was constructed using 249 single nucleotide polymorphism (SNP) markers. The RIL populations were transplanted to the field one month earlier than the standard transplanting period, and plant height (PH), leaf number (LN), and dry weight (DW) were measured to identify quantitative trait loci (QTL) associated with plant growth ability at low temperatures during the seedling stage. QTLs related to cold tolerance, particularly those carrying the ‘Unkwang’ allele, were identified in the PH and DW traits. For PH, the QTLs qPH1, qPH5, and qPH8 were located on chromosomes 1, 5, and 8, respectively. Regarding DW, the QTLs qDW1, qDW8, and qDW9 were identified on chromosomes 1, 8, and 9. For the LN trait, qLN3 carrying the ‘Hanareum2’ allele was located on chromosome 3. If the identified QTLs are utilized, they can be incorporated into breeding programs for plant growth at low temperatures during the seedling stage.

The rice cultivar ‘Chamdongjin’ exhibits a distinctively large grain size and excellent eating quality but is weak with regard to pre-harvest sprouting (PHS), requiring genetic improvement. In contrast, the premium-quality rice cultivar ‘Younghojinmi’ exhibits strong PHS tolerance. This study conducted quantitative trait loci (QTL) analysis on PHS and low-temperature germinability (LTG) using recombinant inbred lines derived from a cross between ‘Chamdongjin’ and ‘Younghojinmi’ to elucidate the genetic factors. Thus, an elite line with improved PHS tolerance was selected. QTL analysis revealed that qPHS3 and qLTG3 were associated with PHS and LTG, respectively, and the candidate gene was identified as qLTG3-1. The loss-of-function allele qltg3-1 in ‘Younghojinmi’ enhanced PHS tolerance compared to the functional allele qLTG3-1 in ‘Chamdongjin,’ but it also showed a trade-off relationship by decreasing LTG. CY_RILs carrying qltg3-1 exhibited lower PHS and LTG rates of 17.9% and 41.6%, respectively, compared to 44.1% and 55.7%, respectively, for CY_RILs with qLTG3-1. The elite line, CY_RIL79, carrying qltg3-1, was selected from CY_RIL. This line was recognized for its PHS tolerance while maintaining the key agricultural traits of ‘Chamdongjin,’ thus designated ‘Jeonju697.’ ‘Jeonju697’ is expected to be utilized as a practical alternative for addressing the issue of enhancing PHS tolerance in ‘Chamdongjin’; however, considering its weak LTG, it is desirable to improve this trait through further breeding efforts.

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).

Kimchi cabbage (Chinese cabbage) is a very common Korean traditional vegetable, cultivated across 32,000 ha, which accounts for about 13% of the total vegetable cultivation area in Korea. Since 2010, frequent occurrences of extreme weather conditions caused a shortage of summer, winter, and autumn Kimchi cabbage. Therefore, the National Institute of Horticultural and Herbal Science (NIHHS) selected a haploid breeding method of microspore culture to develop inbred lines that show resistance under extremely low or high temperature for Kimchi cabbage production. ‘Wonkyo20051ho’ is a double-haploid (DH) inbred line developed using the microspore culture method. Eleven heat resistant parental plants were selected through summer cultivation of 37 resources collected in 2014. Microspore culture was efficient in regenerating four resources, from which 13 DH inbred lines were developed. After artificially inoculating ‘Seosan’ clubroot with low concentration inoculum, 7 inbred lines showing moderate resistance were selected. As a result of the autumn cultivation of 83 breeding plants, including 6 selected inbred lines, the ‘18-FH98’ inbred line forming tight heads with yellow inner leaf under low temperature was finally selected during the 2018 autumn field trial. The selected DH inbred line was named ‘Wonkyo20051ho’ and is expected to be a valuable breeding material possessing tolerance to low temperature and clubroot.

The flour physiochemical properties and end-use quality of wheat were evaluated to identify the effect of high temperature (HT) during grain maturation. HT caused a decrease in the width and thickness of grains. However, HT did not affect the grain weight, volume, length, test weight and 1,000-kernel weight in Korean wheat cultivars. Although HT marginally affected the general flour physiochemical properties and gluten composition, the effects were not significant. Based on the results of the evaluation of end-use quality, the effect of HT on the end-use quality was not significant. Nevertheless, the allelic composition was related to the quantity and quality of grain under HT conditions. In Korean wheat cultivars containing Glu-D1d and -D1f alleles, the 1,000-kernel weight was decreased by HT. In addition, Glu-D1f was more sensitive to HT than was Glu-D1d. The proportion of the y-type high-molecular-weight glutenin subunits (HMW-GSs) was decreased by HT in Korean wheat cultivars containing the Glu-A1ab allele, and was increased in cultivars containing the Glu-B3d allele. Furthermore, the proportions of gliadin and low-molecular-weight glutenin subunits (LMW-GSs) were decreased by HT in Korean wheat cultivars containing Glu-A1ab or Glu-B3ahi alleles.

In this study, we analyzed the growth characteristics and isoflavone content of 43 soybean varieties highly adaptable to highland areas. The flowering period of each cultivation zone was from July 15 to August 12 at Daewallyeong, from July 18 to August 11 at Jinbu, and from July 23 to August 13 at Gangneung. The accumulated temperature from flowering to maturity was 1,297 °C for Daegwallyeong, 1,391 °C for Jinbu, and 1,685 °C for Gangneung. Forty-three varieties were classified into four utilities; soy sauce and tofu, bean sprouts, cooking with rice, and vegetable and early maturity. The content of isoflavone was highest at 2,579 µg/g in varieties for soy sauce and tofu usage. Five varieties (“Paldalkong,” “Sinpaldal2,” “Ilmikong,” “Sinpaldalkong,” and “Daepung”) cultivated in Daegwallyeong had over 4,000 µg/g of isoflavone. The isoflavone content of the region Daegwallyeong was different at the significance level of 0.1 (p=0.061) compared to Gangneung. There was no significant difference between Gangneung and Jinbu. It is thought that the low temperature of the maturation stage during the growing period affected isoflavone accumulation. The varieties with more than 3,000 µg/g of isoflavone content in Daegwallyeong, Jindu, and Gangneung were “L29,” “Williams82,” “Ilmikong,” and “Daepung.” These were genetically and environmentally stable in isoflavone content. It is expected that this study will be used as basic data for the functional breeding and selection of soybean varieties highly adaptable to a specific region, and to help expand soybean cultivation areas in highlands.

‘Jungmo1024’ is a blast resistant early maturing rice cultivar with high temperature tolerance during grain filling stage. ‘Jungmo1024’ was derived from a sodium azide treatment on ‘Suweon472’, a high yielding japonica elite line which was latterly registered as ‘Namil’. Comparison with the agronomical traits of ‘Namil’, ‘Jungmo1024’ was uniquely characterized as the induced gained function due to the reduced culm length, increased tiller number, strong blast resistance and especially high temperature tolerance during grain filling stage. The high temperature tolerance of ‘Jungmo1024’ was supported by two years experiments by comparing the head rice ratio produced in ordinary paddy field and green house condition. The heading date of ‘Jungmo1024’ was July 29 in central plain area, which was 9 days earlier than that of ‘Hwaseong’. The milled rice yield performance of ‘Jungmo1024’ was about 4.98 MT/ha in local adaptability test for three years. ‘Jungmo1024’ had 69 cm in culm length, which was 15 cm shorter than that of ‘Hwaseong’, 20 cm in panicle length, 16 in tiller number, and 22.3g in 1,000 grain-weight of brown rice. ‘Jungmo1024’ exhibited strong rice blast resistance, but do not have any clear resistance gene sources against bacterial blight, viral diseases and insect fests. ‘Jungmo1024’, nevertheless, would be a useful rice cultivar could be used as a donor line for the breeding programs for developing southern plane adaptable early maturing rice cultivars with enhanced rice blast resistance, lodging tolerance, and especially high temperature tolerance during grain filling stage.