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.

Recently, crossbreeding between Asian rice (O. sativa) and African rice (O. glaberrima) has become an important solution for hunger refugees and food problems in Africa by improving grain yield. O. glaberrima exhibits important traits such as stress tolerance, and genetic diversity evaluation and structural analysis of agronomic traits have been conducted. In this study, 11 yield-related agricultural traits were analyzed in 45 lines of O. sativa and 28 lines of O. glaberrima under Korean climatic conditions. Through cluster analysis using the investigated yield-related traits, O. sativa and O. glaberrima were grouped into clusters by characterizing the remaining traits, except for the number of spikelets, grain width, and grain thickness. The number of spikelets was highly influenced by the environment and had the greatest variation, whereas grain width showed the least variation. In addition, rice yield components are quantitative traits, and in breeding to improve yield, it is important to analyze the interaction of agricultural traits and the influence of the environment to maintain an optimal balance and improve plant potential. Although O. sativa was found to exhibit different agricultural traits depending on its ecotype, it still belonged to the same group when clustered. The results of this study provide basic information on the yield-related agronomic characteristics of O. sativa and O. glaberrima under Korean climatic conditions, suggesting that O. glaberrima can be used as breeding material to diversify Korean rice genetic resources.

To stably produce domestic wheat under water-scarce environmental conditions due to climate change, root characteristics with excellent water utilization rates are crucial. In this study, we analyzed the root and grain phenotypes of 37 domestic wheat varieties over a two-year period by combining the results of genetic mutations related to semi-dwarfing and grain size. Root length was positively correlated with maximum root depth (r=0.76**) and total seminal root length (r=0.54**), whereas it was negatively correlated with the number of roots (r=-0.33**) and root angles (r=-0.51**). The thousand-kernel weight was positively correlated with embryo width (r=0.34**) and embryo area (r=0.33**) but was not correlated with other root traits. Embryo length was positively correlated with the number of roots (r=0.34**) and coleoptile length (r=0.42**). Phenotypic analyses of roots and grains, along with genotypic analyses of semi-dwarfing (Rht-B1 and Rht-D1) and grain size (TaCWI-4A, TaCWI-5D, TaGW2-6A, TaSus2-2B) genes, revealed that the Rht-D1b genotype led to reduced root depth, increased root angles, and reduced coleoptile length. TaCwi-A1, TaCWI-5D, TaSus2-2B, and TaGW2-6A, possessing the alleles TaCwi-A1a, Hap-5D-C, Hap-L, and Hap-6A-G associated with a larger grain size, resulted in an increased number of roots and root depth. Domestic wheat varieties were categorized into three clusters based on root, grain, and coleoptile trait characteristics, with 15 varieties in Cluster I, 9 in Cluster II, and 13 in Cluster III. The results of this study can be utilized in basic research to develop varieties that can produce stable domestic wheat by selecting resources with excellent root growth and seed characteristics.

‘Olnuri’ is a new variety of early ripening sweet persimmon obtained in 2006 by crossing the mid-ripening sweet persimmons ‘Shinshu’ and ‘Taishuu’ at Gyeongsangnam-do Agricultural Research and Extension Services. Line selection among the seedlings of ‘Shinshu’ and ‘Taishuu’ hybrids was carried out in 2014, and detailed characteristic investigations on fruit quality and tree growth were conducted from 2018 to 2019. ‘Olnuri’ matured around September 24, an average of 25 days earlier than ‘Uenishiwase.’ The tree is semi-upright, and only female flowers bloom. The trees bear oblate fruits with orange skin. The average weight of the fruit is 280 g, which is significantly higher than that of ‘Uenishiwase’ (190 g). The soluble solids content is higher and the firmness is lower than that of ‘Uenishiwase.’ There is almost no apex splitting or calyx end cracking. The marketable fruit rate is 80.0%, which is lower than that of ‘Uenishiwase’ (91.2%, data not shown). In the future, as a fully ripened persimmon in late September, ‘Olnuri’ is expected to play a big role in creating the sweet persimmon market during the autumn harvest period (Registration No. 8917).

‘KM5,’ a high grain yielding maize hybrid, was developed for the Southeast Asian seed market in 2018 by the maize breeding team of the National Institute of Crop Science (NICS), Rural Development Administration (RDA). ‘KM5’ was bred by crossing two inbred lines—14K23 and CL59. After a 1-crop year yield trial in Dong Trieu and Vietnam, country adaptability trials were performed in 2017 and 2018 in three different countries—Vietnam, Cambodia, and Indonesia. The seed type is flint-like and suitable for both food and feed. ‘KM5’ adapted well to northern Vietnam, northwestern Cambodia, and Central Java in Indonesia. It is an early maturing, high grain yield F1 hybrid that is also resistant to downy mildew. The silking date of ‘KM5’ in Vietnam is 74 days, which is the same as that of LCH9—a leading cultivar in Vietnam. ‘KM5’ produced a grain yield of 695, 764, and 678 kg/10a in Vietnam, Cambodia, and Indonesia, respectively, thus demonstrating a higher yield than the leading cultivar in each country. ‘KM5’ produced 2%, 27%, and 8% more grain than the respective control varieties in Vietnam, Cambodia, and Indonesia, respectively (Registration No. 8947).

‘KM3’ is an F1 hybrid maize developed by the maize breeding team at the National Institute of Crop Science (NICS), Rural Development Administration (RDA), for the Southeast Asian seed market. This hybrid was obtained by crossbreeding two inbred lines—14K26 and 15VL027. The hybrid was evaluated in a crop-year yield trial in Cambodia, followed by country adaptability trials in Cambodia and Indonesia in 2016 and 2017, respectively. The flint-like seed type of ‘KM3’ makes it suitable for both food and feed, demonstrating its adaptability to Southeast Asia. ‘KM3’ exhibited early maturity, high grain yield as an F1 hybrid, and resistance to downy mildew. The silking date of ‘KM3’ was two days earlier than that of the leading cultivar ‘CP888’ in Cambodia, with a grain yield of 913 kg/10a, outperforming ‘CP888’ by 26% (Registration No. 9319).

‘Saebonghwang’ was developed as a mid-late ripening rice variety with good cultivation stability and yield in transplanting and under direct seeding cultivation. It was bred by backcrossing ‘Hopum’, which has excellent cultivation stability and adaptability to direct seeding, as a repeat parent, and ‘Hitomebore,’ a Japanese rice variety with excellent taste, as a donor. The heading date of ‘Saebonghwang’ was August 11 under ordinary planting, which is two days earlier than that of ‘Nampyeong’, and August 13 under wet-direct seeding cultivation, which is the same as that of ‘Dongan’. ‘Saebonghwang’ had a culm length of 74 cm under wet-direct seeding cultivation, which is larger than that of ‘Dongan’ (69 cm), and had good cultivation stability, including lodging resistance. ‘Saebonghwang’ is resistant to bacterial leaf blight and rice stripe virus and shows moderate resistance to rice blast. Furthermore, ‘Saebonghwang’ has better grain appearance, superior taste and better milling characteristics than ‘Nampyeong’. The yield of ‘Saebonghwang’ when cultivated under ordinary planting, wet-direct seeding, and double cropping was 5.65, 5.37, and 5.37 MT/ha, respectively. Under wet direct sowing by drone cultivation, ‘Saebonghwang’ showed good initial survival rate and cultivation stability. The yield was 4.49 MT/ha, slightly lower than that obtained under transplanted cultivation (5.03 MT/ha), but was not statistically different; therefore, ‘Saebonghwang’ was adjudged to be adaptable to drone wet-direct seeding. ‘Saebonghwang’ can be used in various ways to suit the working conditions of farms, increase farm work efficiency, and expand the area of wet direct-seeding cultivation (Registration No. 9171).

‘Jinhyang’ is a fragrant pear bred in 2019. Field crossings to breed fragrant pears were conducted in 1984 at the Pear Research Center of the National Institute of Horticultural and Herbal Science. The maternal and paternal parents were ‘Okusankichi’ (IT254489) and ‘Hori’ (IT226291), respectively. The 84-16-5 line, which had a good fragrance, was first selected in 2007, and regional adaptation tests were conducted from 2011 to 2019 in five regions (Suwon, Chuncheon, Jinju, Yecheon, and Naju). The morphological characteristics of ‘Jinhyang’ include vigorous spreading tree form, brown-colored one-year-old shoot, elliptical leaf blade, round leaf tip, and white-colored flowers. The full bloom date was April 11, and the harvest date was in late September. The fruit of ‘Jinhyang’ weighs 439.9 g and has a soluble solid content of 13.0 °Brix, with a good sugar-acid balance and abundant juice. Analysis of the fragrance components of ‘Jinhyang’ revealed the presence of a large amount of fragrant volatile compounds compared to that of the standard cultivar ‘Niitaka’. In particular, ‘Jinhyang’ contains ethyl hexanoate and ethyl butanoate, which are known volatile compounds generated by pineapple and mango. Because of its strong uprightness, cultivation management, such as shoot bending, is necessary to maintain flower buds (Registration No. 9387).

Rice is a staple crop in South Korea and globally. The era of global boiling, characterized by rising temperatures and abnormal climatic conditions, significantly impacts crop production worldwide. This study examines the effects of high temperatures and rainfall on early maturing rice varieties, focusing on enhancing heat tolerance during the ripening stage and preharvest sprouting resistance. Utilizing ‘Milyang247,’ a progeny line from ‘Nampyeong,’ we developed the intermediate line ‘MY362VP.’ During 2020–2022, regional adaptability tests were conducted at five locations across Korea. Results showed that ‘MY362VP’ had a viviparous germination rate of 1.9% compared to 19.0% in the control variety ‘Jopyeong.’ Furthermore, ‘MY362VP’ maintained a head rice rate of 90.6% under high temperature conditions, outperforming ‘Jopyeong,’ which has a rate of 62.1%. ‘MY362VP’ produced an average yield of 529 kg/10a, comparable to the control’s 518 kg/10a. This study offers valuable insights for breeding climate-resilient early-maturing rice varieties, positioning ‘MY362VP’ as a promising candidate for future cultivation.