‘Amissal’ is a regionally specialized rice cultivar developed to strengthen the competitiveness of local rice and is characterized by its distinct long-grain japonica type. It was bred through a single backcross between ‘Boramchan’—a high-yielding japonica cultivar with excellent cultivation stability used as the recurrent parent—and ‘HR30198-AC33’ (DGS79), a breeding stock with extra-long and spindle-shaped grains used as the donor parent for japonica grain shape diversification. Population and pedigree breeding methods were used during the breeding process. During the selection stage, molecular marker-assisted selection targeting the major grain shape genes, GS3 and qSW5 was applied, enabling the identification of lines carrying the gs3-qSW5 allele combination associated with long grain shape. ‘Amissal’ was developed through yield trials, local adaptability tests, selection trials addressing regional needs, and on-farm research aimed at developing long-grain japonica rice for export. The heading date of ‘Amissal’ was August 17, two days later than that of ‘Nampyeong’. Compared to ‘Nampyeong’, ‘Amissal’ exhibited greater biomass due to longer culms, more spikelets per panicle but fewer panicles per hill, and a heavier 1,000-grain weight. It demonstrated strong resistance to bacterial blight (races K1, K2, and K3) but was susceptible to viral diseases and insect pests. In terms of yield, it outperformed ‘Nampyeong’. The average brown rice grain length was 6.14 mm, classifying it as long-grain type. The length-to-width ratio was 2.43, corresponding to a semi-spindle shape, which clearly distinguishes it from existing Korean japonica cultivars. While its milling recovery rate was similar to that of ‘Nampyeong’, a high proportion of broken rice due to its long grain shape resulted in a lower head rice. ‘Amissal’ had low protein content and provided the sticky and soft texture typical of japonica rice, with excellent scores in sensory evaluation tests. As a differentiated, regionally specialized rice cultivar featuring a long-grain japonica type and superior eating quality, ‘Amissal’ is expected to contribute to the advancement of the local rice industry, particularly through applications in rice export and the utilization of broken rice and rice straw (Registration No. 10167).

Early selection of grain quality traits in rice (Oryza sativa L.), is essential to improve the yield and quality of this staple crop. We analyzed four key traits—protein content, grain filling rate, height, and panicle length—in 85 Korean cultivars. Through whole- genome resequencing we identified 12,718,879 raw single nucleotide polymorphisms (SNPs); after PLINK-based quality control (bi-allelic selection, call rate≥0.90, MAF≥0.03), ~2.20 million high-quality SNPs remained for machine-learning (ML) pre-screening. To rank the features (without marker-level inference), we applied a liberal univariate PLINK case-control scan using the top and bottom 30% per trait. We also analyzed associations with a linear mixed model (GCTA v1.93.2, MLMA; fixed covariates: ecotype, PC1, PC2; random effect: GRM) to verify calibration under population structure; with n=85, no genome-wide significant hits were detected, and QQ-plots indicated adequate calibration (per-trait effective tests m≈1.54-1.57 million under stricter filters). The random forest feature importance prioritized 26, 51, 19, and 20 core SNPs for the four traits, respectively. Across the algorithms, the best models achieved mean accuracies of 81.8% (protein content), 81.0% (grain filling rate), 73.1% (height), and 94.0% (panicle length). All selected SNPs met the Fluidigm array design requirements, supporting its deployment as a compact, genotype-based panel for early selection and a practical step toward digital breeding in rice.

The intermediate breeding material ‘JJ625LG’ was developed to diversify the grain shape characteristics of Korean japonica rice cultivars. ‘JJ625LG’ was derived from a cross between ‘HR30198-AC33 (DGS79),’ a japonica breeding material with extra-long and spindle-shaped grains, and ‘Boramchan,’ a high-yielding japonica cultivar with excellent cultivation stability and medium-short and semi-round grains. By employing both bulk and pedigree breeding methods, strong selection pressure was applied to eliminate undesirable traits inherited from ‘DGS79,’ such as very late heading, long awns, and susceptibility to lodging. Consequently, elite lines with long spindle-shaped grains on a japonica background were selected. These lines subsequently underwent yield performance and local adaptability tests, during which their agronomic traits were comprehensively evaluated, leading to the final selection of ‘JJ625LG.’ The heading date of ‘JJ625LG’ was August 16th, three days later than that of ‘Nampyeong’. Its culm length was similar to ‘Nampyeong.’ ‘JJ625LG’ exhibited a higher number of spikelets per panicle, fewer panicles per plant, and heavier 1,000-grain weight than brown rice. Additionally, it showed strong resistance to bacterial blight (races K1, K2, and K3) but was susceptible to viral diseases and insect pests, indicating the need for further improvement in these areas. Its grain yield was comparable to that of ‘Nampyeong.’ With a brown rice grain length of 6.34 mm, ‘JJ625LG’ was classified as a long-grain type and had a grain length-to-width ratio of 2.64, reflecting a spindle-shaped morphology. It carried the GW2-gs3-qSW5 allele combination associated with grain shape, which is a genetic profile not found in existing Korean japonica cultivars. Although its milling recovery rate was similar to that of ‘Nampyeong,’ the presence of many broken rice due to its long grain shape resulted in a lower percentage of head rice. The eating quality of ‘JJ625LG’ was excellent, with its grains exhibiting the sticky and soft texture typical of japonica rice and receiving high scores in sensory evaluation. As the first intermediate breeding material in Korea with long and spindle-shaped grains in a japonica background, ‘JJ625LG’ is expected to contribute significantly to diversifying the traditionally narrow grain shape spectrum of Korean japonica rice cultivars (Registration No. 10166).

The decrease in seed vigor and grain quality during storage has become an increasingly critical issue due to the extended storage periods resulting from declining rice consumption and climate change in Korea. Despite its importance, few studies have investigated rice seed aging in a large number of Korean rice cultivars. In this study, 53 japonica rice cultivars were evaluated for seed germination, vigor, and grain quality-related traits under accelerated-aging conditions. Seed germination rate was evaluated 7 days after imbibition, following accelerated aging treatments at 42℃ and 95% relative humidity for 8, 12, and 16 days. The average germination rates were 72.9% in the control (0 d), 71.7% after 8 days, 59.0% after 12 days, and 5.6% after 16 days of treatment. Grain quality-related traits, including texture and pasting properties, were also evaluated in rice subjected to the accelerated aging treatment. Adhesiveness and stickiness decreased, whereas hardness and toughness increased, as seed aging progressed. Cluster analysis based on germination rates after accelerated aging identified three distinct clusters, with cultivars in Cluster 3 maintaining a high germination rate of 70.6% even after 12 days of aging, showing clear differences from the other clusters. A principal component analysis (PCA) was conducted to investigate the relationship between germination rate and grain quality-related traits. The results showed that the germination rate and hardness tended to be negatively associated across all three clusters. These results suggested that cultivars with higher germination rates tend to maintain a softer cooked rice texture after aging. Our results provide insight into the relationship between seed aging and grain quality, highlighting elite cultivars that maintain both germination ability and grain quality during storage as valuable resources for breeding programs.

Breeding wheat cultivars with high nitrogen use efficiency is crucial for sustainable agriculture. In this study, 130 durum wheat accessions from 53 countries were cultivated under two nitrogen fertilization levels to investigate variations in agronomic traits and identify accessions suitable for low-nitrogen conditions. Under no nitrogen fertilization, SPAD value (-99.2), flag leaf length (−15.8 mm), grain area (−0.52 mm²), grain length (−0.27 mm), thousand-grain weight (+5.2 g), and grain protein content (−4.2%) showed significant differences compared to that under standard nitrogen fertilization. Among these traits, the SPAD value exhibited a strong positive correlation with protein content in the absence of nitrogen fertilization, suggesting its potential as an indicator for selecting germplasm with superior nitrogen use efficiency. Hierarchical cluster analysis, based on the differences in the six traits under the two nitrogen fertilization levels, classified the 130 durum wheat accessions into three groups (Groups 1, 2, and 3). Accessions in Group 2 exhibited superior adaptability under no nitrogen fertilization compared with those in the other two groups. We identified seven accessions in Group 2 that exhibited minimal decreases in SPAD values and protein content under no nitrogen fertilization for use in wheat breeding programs aimed at developing cultivars with high nitrogen use efficiencies.

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.

The grain size and shape have a significant impact on the grain quality and yield of rice. Additionally, due to the globalization of the rice market, there is a demand for rice varieties of various sizes. In this study, we analyzed quantitative trait loci (QTL) associated with grain length (GL), grain width (GW), grain thickness (GT) and ratio of length-to-width (RLW) using 149 F₂ plants obtained from a cross between Hopum and Basmati 370. To construct a linkage map, we utilized 89 Fluidigm SNP markers, which covered a span of 1,116 cM of F₂ population. Nine QTLs associated with four traits were identified on chromosomes 2, 3, 5, and 7. One major QTL on chromosome 3 accounted for 43.2% of the phenotypic variation in GL. Additionally, QTLs named qGW2 and qGW5 on chromosomes 2 and 5 were detected for GW, explaining 10.4% and 18.6% of the phenotypic variation, respectively. Three QTLs for GT were found on chromosomes 2, 5, and 7, explaining 9.9%, 12.9%, and 9.9% of phenotypic variation, respectively. These QTLs offer potential applications in breeding programs using Basmati 370 to develop long and slender grain japonica varieties.

Rice is an important food crop that feeds most of the world's population. However, due to the increased frequency of pest outbreaks, it is necessary to cultivate complex pest-resistant rice cultivars. A mutant population was derived by culturing tissue of ‘Hwayeong’ at the Plant Molecular Breeding laboratory of Kyungpook National University in the Republic of Korea. The cultivar ‘Drimi4ho’, a line that was resistant to complex disease, was finally selected by backcrossing with ‘Junam’. The heading date of ‘Drimi4ho’ is August 11 (107 days after sowing). Drimi4ho’ has culm length of 69 cm, panicle length of 21 cm, 16 panicles per hill, 115 spikelets per panicle, a ratio of ripened grain of 92.7%, and a 1,000-grain weight of 24.3 g. No lodging occurred when ‘Drimi4ho’ was grown in the field by standard fertilization. It is also resistant to leaf/neck blast disease, bacterial blight (K₁, K₂, K₃), rice dwarf virus, rice black-streaked dwarf virus, rice stripe virus, BPH, and SBPH. ‘Drimi4ho’ is a round and short-type grain, and is very clear and transparent without chalkiness. In addition, it has excellent physicochemical properties that make up food, so its taste is good. When ‘Drimi4ho’ was planted under ordinary conditions in the southern mountainous area of Korea, the yield was 5.53 MT/ha (Registration No. 6124).

‘Heugho’, a new cultivar developed in 2014, is a two-rowed hulled barley with black grains that was selected among doubled haploid lines produced by anther culture from a backcross between two cultivars. Black barley, which has black grains, was used as the donor parent and ‘Hopum’, which has an elite genotype, was used as the recurrent parent. Agricultural characteristics of the new cultivar such as heading date, lodging and disease resistance were similar to those of ‘Hopum’. The yield was approximately 3.8 ton/ha, which was also comparable to that of ‘Hopum’. In terms of grain quality, the thousand grain weights of ‘Heugho’ and ‘Hopum’ were similar at 44.9 g and 41.4 g, respectively. The malt quality of both cultivars, which was mainly determined by extract, diastatic power, Kolbach index, and soluble protein content, were also similar. The total polyphenol contents of ‘Heugho’ and ‘Hopum’ malts were 0.274% and 0.244%, and the anthocyanin contents were 37.1 µg/g and 16.5 µg/g, respectively. After malting, ‘Heugho’ had high antioxidant capacity, making it a functional food source for beer as well as tea. We expect that ‘Heugho’ will contribute to farmer’s income and regional economic activation associated with the barley processing industry(Registration No. 8239).

Rice is a staple food in most countries, and thus, diversifying its value is necessary. Recently, the focus on good health has increased, and rice cultivars with improved properties should be bred based on consumer demands. At the Plant Molecular Breeding Laboratory of Kyungpook National University, “Hwayeong” was tissue-cultured to derive mutant populations. In the mutant lines, “P35” with high protein content and excellent agricultural traits, was backcrossed with “Ilmi” three times, and the final selected line was called “Drimi5ho.” The heading date of “Drimi5ho” was August 11 (107 d after sowing), which was 5 d later than that of “Ilmi” (August 5, 101 d after sowing). The culm length of “Drimi5ho” was 71 cm, the panicle length was 18 cm, the number of panicles per hill was 13, the number of spikelets per panicle was 113, the ratio of ripened grain was 90.5%, and the 1,000-grain weight was 22.6 g. When "Drimi5ho" was planted ordinary plantation, the yield in the southern mountainous area was 526 kg/10a. Lodging was not observed when “Drimi5ho” was grown in the field with standard fertilization (N-P₂O₅-K₂O = 9-4.5-5.7 kg/10a). This rice cultivar was resistant to leaf/neck blast, bacterial blight (K₁, K₂, and K₃), rice stripe virus, rice black-streaked dwarf virus, and rice dwarf virus. The milled grain of “Drimi5ho” was clear and transparent without any chalkiness; moreover, the grain shape was round and short. Although it is a specialty rice with increased protein content, the taste of the rice and the grain quality were excellent (Registration No. 6829).

Rice is one of the most important food crops in the world, but brown planthopper (BPH, Nilaparvata lugens stal) causes a significant loss of rice yield. Due to climate change, different races of rice-damaging species are evolving at an accelerated pace, thus, creating a need to breed multi-resistant rice cultivars for a stable food supply. In 2001, “Samgang” and “Nagdong” were crossed at the Plant Molecular Breeding Laboratory of the Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu Korea. “Drimi3ho” is a resistant and high-quality rice cultivar that was bred by backcrossing a line having excellent agronomic traits with “Ilmi.” The heading date of “Drimi3ho” was August 12 (104 d after sowing), and it was a medium-maturing cultivar that matured 3 d earlier than “Ilmi” (August 15, 107 d after sowing). Its culm length was 81 cm, panicle length was 18 cm, panicle number per hill was 16, spikelet number per panicle was 113, ripened grain ratio was 93.2%, and 1,000-grain weight was 24.3 g. “Drimi3ho” was highly resistant to blast disease and bacterial blight (K₁, K₂, and K₃), rice stripe virus, rice dwarf virus, rice black-streaked dwarf virus, and BPH. When “Drimi3ho” was milled, the milled grain was clear and transparent; moreover, the grains were semi-round and short-type. Moreover, “Drimi3ho” had lower protein and amylose content and tasted better than “Ilmi.” When “Drimi3ho” was grown on an ordinary plantation in the southern mountainous area, the yield was 563 kg/10a (Registration No. 5621).

Rice is an important crop used as a staple food in most of the world; however the occurrence of pests is increasing due to climate change. In particular, the brown planthopper (BPH, Nilaparvata lugens stal) is a key cause of rice yield loss. In response to the era of unpredictable climate change in the future, the Plant Molecular Breeding laboratory of the Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu 41566, Korea bred the ‘Drimi2ho’ strain, which is resistance to BPH or various pests and of excellent eating quality. In order to cultivate ‘Drimi2ho’, ‘Samgang’ and ‘Nagdong’ were crossed and the derived seeds were backcrossed with ‘Junam’, and the pedigree breeding method was applied. During the application of the pedigree method, agricultural characteristics which are investigated in the field were found to be excellent, and the best line for various disease resistance, grain quality, and yield was finally selected as ‘Drimi2ho’. ‘Drimi2ho’ has strong resistance to BPH and its range of resistance to major pests and viral diseases such as blast and bacterial blight on rice is quite wide. In the field, the main agricultural characteristics of ‘Drimi2ho’ were similar to or improved from those of ‘Junam’. ‘Drimi2ho’ is a cultivar with enhanced disease and pest resistance and a wide spectrum while maintaining the good eating quality. ‘Drimi2ho’ yielded 584 kg/10a in ordinary cultivation under normal level of fertilization in south mid-mountainous areas of Korea. Drimi2ho’ can thus be a standard cultivar in Korea due to its varied resistance to multiple diseases and excellent grain quality. (Registration No. 4686).

‘Sinhwangok2’ is a single cross maize F₁ hybrid (Zea mays L.) that was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA, in 2018. This yellow high-yielding intermediate maize hybrid was obtained by crossing between two inbred lines― KS214 and KS215. After advanced yield trials over two years in Suwon, a regional yield trial for ‘Sinhwangok2’ was conducted to evaluate its growth and yield at three different locations, from 2016 to 2018. ‘Sinhwangok2’ requires 72 days for silking and its plant height is 243 cm, similar to that of ‘Jangdaok’; its ear height ratio is 49%, like that of ‘Jangdaok’, and the hybrid shows resistance to lodging. The number of ears per 100 plants was found to be 100 and the ear length of ‘Sinhwangok2’ is 19.5 cm, which is shorter than that of ‘Jangdaok’. The weight of 100 seeds of ‘Sinhwangok2’ is 30.8 g, similar to that of ‘Jangdaok’. This hybrid shows moderate resistance to southern leaf blight (Bipolaris maydis). It has moderate resistance to European Corn Borer (Ostrinia nubilalis). The grain yield (i.e., 9.41 ton/ha) of ‘Sinhwangok2’ was found to be 13%, which is higher than that of ‘Jangdaok’. Seed production of ‘Sinhwangok2’ was 2.36 ton/ha and was considered acceptable due to a good synchronization of flowering period during crossing between the seed parent, KS214, and the pollen parent, i.e., KS215, in Yeongwol and F₁ seed yield. ‘Sinhwangok2’ can thus be a suitable cultivar for all plain areas in Korea and can possibly be cultivated via double cropping with winter forage crop because of their early maturity. (Registration No. 8963).

To improve the seed purity management system of Korean wheat cultivars, 50 Korean wheat cultivars were subjected to chemical assays for grain color, genotyping of grain weight-related genes, and grain image analysis. The tested cultivars were primarily classified by NaOH and ninhydrin tests as white (26%) and red (74%) cultivars, as well as high PPO activity (48%), and low PPO activity (52%) cultivars, respectively. The allelic variations of Tamyb10 gene revealed Tamyb-A1a/Tamyb-B1a/Tamyb-D1a as the major allelic combination in white wheat and five different Tamyb10 genotypes (i.e., aba, abb, baa, bba, and bbb) in red wheat. Those cultivars with high PPO activity possessed the Ppo-A1a/Ppo-B1b/Ppo-D1b genotype, while those with low PPO activity possessed the Ppo-A1b/Ppo-B1a/Ppo-D1a genotype. In the grain image analysis, long grain cultivars displayed increased grain width, circularity, and area. Based on cluster analysis of grain traits, the Korean wheat cultivars were classified into two groups - 1) large red grain cultivars released before 2000, and 2) small red grain cultivars and white wheat cultivars released after 2000. Further research is required to determine the effects of grain filling conditions on the grain characteristics of Korean wheat cultivars and to develop efficient and reliable molecular markers for an improved seed purity management system.

Temperate japonica is used as the parent for crossing in the breeding of new rice cultivars in Korea, and the grain shape of the developed lines or cultivars is a semi-round and medium-short grain length. To overcome the current low quantity of japonica cultivar germplasm and deterioration in quality caused by climate change, it is necessary to diversify the grain characteristics of japonica. Most of the United States (US) cultivars are classified as medium, long, extra-long, and half spindle- and spindle-shaped grains. The qSW5 allelotype, a major gene involved in grain width, is found in all US cultivars. In addition, the US cultivar ‘Saber’ has both qgl3 and GS3_B alleles, which have low allele frequencies among Korean rice cultivars, and ‘A020’ had gw8, an allele with a reduced grain width. The pasting properties and texture of medium-grain length and half-spindle-shaped cultivars were relatively similar to those of the Korean rice cultivar, but different from those of long-grain and long spindle-shaped cultivars. Therefore, grain shape is associated with pasting properties and texture traits. Among the rice cultivars in the US, tropical japonica belongs to the same japonica as the Korean rice cultivar; however, its grain shape is similar to that of indica. As grain shape is also related to grain quality, US cultivars can be used as a useful genetic resource for diversifying the grain characteristics of Korean japonica cultivars and breeding new cultivars.

The rice variety ‘Youngjin’ is a japonica rice (Oryza sativa L.) with good eating quality, lodging tolerance, and resistance to the rice stripe virus (RSV) and bacterial blight disease (BB). It was developed by the rice breeding team of the Department of Southern Crop, NICS, RDA, in 2016. This variety was derived from a three-way cross between ‘Iksan486’, ‘YR22722-B-B-B-25-1’, and ‘Chengmu,’ with good eating quality, in the summer of 2007. The pedigree of ‘Youngjin’ was YR27874Acp46-1, and was designated as ‘Miyang283’ in 2012. After local adaptability tests at five different locations from 2014 to 2016, it was released under the name ‘Youngjin’ in 2016. ‘Youngjin’ is a mid-late maturing ecotype with a short culm length of 67 cm. This variety was found to be resistant to the K1, K2, and K3 races of BB, and RSV, and moderately resistant to leaf blast disease. The milled rice kernels of ‘Youngjin’ were translucent and clear, without white core and belly, and had good eating quality, according to a panel test. This variety showed a lower percentage of cracked kernels compared to other susceptible cultivars. The milled rice yield of ‘Youngjin’ was 568 kg/10a, under normal levels of fertilization, determined by the local adaptability tests. This cultivar is adaptable to the Yeongnam plain area (Registration No. 7653).

Kernel weight is a vital trait for selecting high-yielding wheat in breeding programs. We evaluated the thousand-kernel weight (TKW), test weight (TW), grain length (GL), grain width (GW), grain thickness (GT), and grain roundness (GR) of 41 Korean winter wheat cultivars over a period of 4 years. Correlation analyses revealed that TKW was positively correlated with GL (r=0.76***), GW (r=0.85***), and GT (r=0.84***), whereas TW was negatively correlated with GL (r=-0.38*) and GT (r=-0.31*). Allelic variation was analyzed for 13 kernel weight-related genes/loci (TaCwi-A1, TaCWI-4A, TaCWI-5D, TaGW2-6A, TaTGW6-A1, TaTGW-7A, TaGS1a, TaSus1-7A, TaSus1-7B, TaSus2-2B, TaCKX6-D1, TaCKX6a02-D1, and TaSnRk2.3). Significant associations between the allelic variation and kernel traits were identified in TaCWI-4A (TW, GL, and GR), TaCWI-5D (TKW), TaGW2-6A (TKW, GL, GW, and GT), TaSus2-2B (TKW, GL, GW, and GT), and TaGS1a (TW). In contrast, we detected no significant association between the allelic variation of TaCwi-A1, TaTGW6-A1, TaSus1-7A, and TaSus1-7B and variations in kernel traits. Also, TaTGW-7A, TaCKX6-D1, TaCKX6a02-D1, and TaSnRK2.3 were found to be monomorphic. The four loci TaCWI-4A, TaCWI-5D, TaGW2-6A, and TaSus2-2B showed significant phenotypic differences, a totalof 10 different haplotypes (AC1-AC10) were observed at four loci among the Korean wheat cultivars. Cultivars with the AC1 haplotype exhibited significantly higher TKW than those with the AC8 haplotype, which comprises alleles for high TKW at all four loci, indicating that additional loci controlling kernel weight might be present in the high TKW cultivars.

In order to investigate salt-tolerant sorghum germplasms that can grow in saline soil from newly reclaimed land, we measured a well-established germination rate, and growth characteristics including leaf number, height, and root length in salt-treatment conditions (0.3, 0.6, 0.8, and 1.2%) and untreated control. The highly salt-tolerant sorghum line was confirmed using PCA (principal component analysis) analysis and fuzzy comprehensive evaluation method. Germination rate gradually decreased at doses higher than 0.3%, but the germination rates reached about 70% in IT124115, IS1041, Dansusu4ho, and Dansusu2ho germplasms. At 0.6% salt-treatment condition, the germination rates ranged from 35% to 100%. Only seven germplasms (IT103274, IT101381, IT104110, Dansusu4ho, IS20740, IS22720, and IS27887) had germination rates exceeding 50% at 0.8% salt-treatment. At 1.2% salt-treatment IT124115, IT028385, and IS1041 withered. The total number of leaves decreased similarly for both germplasms at salt levels below 0.6%, and sweet sorghum leaf count was more susceptible than grain sorghum at doses higher than 0.8%. In addition, the height of both germplasms was severely reduced even at low salt concentrations, whereas grain sorghum exhibited a greater sensitivity to salinity stress in terms of root length, while sweet sorghum had longer roots at low concentrations when compared with the untreated control. PCA analysis and fuzzy comprehensive evaluation showed that 29 sorghum accessions could be divided into 3 groups based on the germination rate and morphological traits. Especially, sweet sorghum accessions showed a different pattern of PCA plot when compared with the grain sorghum, and salt tolerance could be divided into 5 groups using MFV in terms of their traits. Taken together, the results from this work will contribute to the development of domestic agriculture utilizing marginal land such as reclaimed land by selecting elite sorghum germplasms that have a high salt tolerance and capacity.

‘Yechan’ is a high grain quality mid-late maturing rice cultivar with lodging tolerance and multiple disease resistance. It was a derived from a cross between ‘Hopum’ and ‘Iksan537’ (cultivar name ‘Haepum’). ‘Hopum’ is a high grain quality mid-late maturing rice cultivar with strong lodging tolerance and ‘Haepum’ is a high grain quality medium maturing rice cultivar with multiple disease resistance. To shorten the breeding period, another culture method was applied to the F₁ plants. ‘Yechan’ was selected through the pedigree method, yield trials, and local adaptability tests, with a high selection pressure for grain quality, lodging, and disease resistance. The heading date of ‘Yechan’ was August 14, one day later than that of ‘Nampyeong’. ‘Yechan’ is a cultivar tolerant to lodging and it has short culms. It has multiple disease resistance against rice blast, rice stripe virus, and bacterial blight, including the K3a race, the most virulent race in Korea. The yield of ‘Yechan’ was similar to that of ‘Nampyeong’. ‘Yechan’ showed excellent grain appearance, superior taste when cooked, and enhanced milling performance; thus, we concluded that it could contribute to the improvement of Korean japonica rice cultivar quality. ‘Yechan’, a high grain quality mid-late maturing rice cultivar with lodging tolerance and multiple disease resistance, would be suitable for cultivation in the southern plain area in Korea and has been utilized in the breeding programs aimed at enhancing the grain quality and stability for the cultivation of Korean japonica rice (Registration No. 7647).

‘Yeongbo’ is a variety of japonica rice (Oryza sativa L.) with good eating quality, resistance to rice stripe virus, rice dwarf virus, and bacterial blight disease. It was developed by the rice breeding team of the Yeongdeok Branch, National Institute Crop Science, Rural Development Administration in 2014. This variety was derived from a cross between ‘Yeongdeog35’ with good eating quality and ‘Saekyehwa’ with good plant type in the 2002 summer season. A promising line selected through the pedigree breeding method, YR24269-1-2-1-2-3-3, was designated as ‘Yeongdeog57’ in 2011. After a local adaptability test at nine locations from 2012 to 2014, ‘Yeongdeog57’ was released under the name of ‘Yeongbo’ in 2014. ‘Yeongbo’ had a short culm length of 66 cm and medium growth duration. This variety was resistant to K1, K2, and K3 races of bacterial blight, rice stripe virus, and dwarf virus, and moderately resistant to leaf blast disease. ‘Yeongbo’ had translucent and clear milled rice kernel without white core and belly, and good eating quality according to a panel test. The yield potential of ‘Yeongbo’ in milled rice was approximately 5.75 MT/ha at an ordinary fertilizer level in the local adaptability test. This cultivar would be adaptable to middle plain area, south plain area, Yeongnam plain area, east costal area, and south mid-mountainous area. (Registration No.6804)

‘Haepum’ is a bacterial blight-resistant, medium maturing rice cultivar with high grain quality. It was derived from a cross between ‘Iksan493’ (cultivar name ‘Jinbaek’) and the F₁ cross between ‘Iksan495’ (‘Dacheong’) and ‘Iksan496’ (‘Jungmo1005’). Of these three cultivars, ‘Jinbaek’ is a bacterial blight-resistant mid-late maturing rice cultivar with high grain quality, ‘Dacheong’ is a mid-late maturing rice cultivar with multiple resistance to disease and insects, and ‘Jungmo1005’ is a mid-late maturing rice cultivar with lodging tolerance. To develop fixed lines, the anther culture method was applied to F₁ plants. The cultivar ‘Haepum’ was selected using the pedigree method, yield trials, and local adaptability tests. The heading date of ‘Haepum’ was August 11^th, three days earlier than that of ‘Nampyeong’ cultivar. Haepum’ is a cultivar tolerant to lodging and it has short culms. Due to its low rate of viviparous germination, ‘Haepum’ could be useful for preventing pre-harvest sprouting in cultivation of medium maturing rice in the southern plain area of Korea. ‘Haepum’ carries two bacterial blight resistance genes (Xa3 and xa5), and in our study, it exhibited high-level and broad-spectrum resistance against bacterial blight, including K3a, the most virulent race in Korea. ‘Haepum’ is also resistant to the rice stripe virus and moderately resistant to rice blast. The yield of ‘Haepum’ was similar to that of ‘Nampyeong’. ‘Haepum’ showed excellent grain appearance and good taste of cooked rice, and therefore it could contribute to the development of bacterial blight-resistant rice cultivars of improved quality. ‘Haepum’ would be suitable for cultivation in the southern plain area of Korea as well as in bacterial blight-prone areas. (Registration No. 6068)

‘Hwangdaok’, a new maize F1 hybrid (Zea mays L.), was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2016. The high-yielding yellow dent hybrid named ‘Hwangdaok’ was obtained by crossing between two inbred lines, ‘KS203’ and ‘KS190’. After advanced yield trial in Suwon in 2012, regional yield trial was subsequently carried out to evaluate the growth and yield of ‘Hwangdaok’ at three different locations from 2014 to 2016. The number of days to silking of ‘Hwangdaok’ is 76. The plant height is 262 cm and ear height ratio is 51%, which are similar to those of ‘Jangdaok’. It has resistance to lodging. The number of ears per 100 plants is 95. The ear length is 21.3 cm and weight of 100 seeds is 34.7 g, similar to those of ‘Jangdaok’. It has moderate resistance to southern leaf blight (Bipolaris maydis) and European corn borer (Ostrinia nubilalis). The grain yield (10 ton/ha) of ‘Hwangdaok’ is 6% higher than that of ‘Jangdaok’. The seed production rate of ‘Hwangdaok’ is acceptable due to good synchronization of flowering period during crossing between the seed parent, KS203, and the pollen parent, KS190, in Yeongwol. F1 seed yield was 1.68 ton/ha. ‘Hwangdaok’ can be a suitable cultivar to plain areas in Korea. (Variety registration No. 7502).

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.

‘Hwawang’ is an early maturing and short statured rice cultivar adaptable to the rice–cash crop rotation system that was developed by the rice breeding team of the Department of Southern Crop, National Institute of Crop Science (NICS), Rural Development Administration (RDA), Korea, in 2012. This cultivar was derived from the cross of YR25867 (Hitomebore//YR21247-B-B-B-49-1/Sasanishiki BL4) and YR25866 (Akidagomachi//YR21247-B-B-B-49-1/Sasanishiki BL4) during the 2005/2006 winter season and was fixed as a homozygous line by a doubled haploid breeding system. In the replicated yield trial in 2009, a promising line (YR26253Acp26-1) showed a good phenotype and high yield potential, and so it was selected and designated as ‘Milyang256’. The local adaptability test of ‘Milyang256’ was carried out at three locations from 2010 to 2012. It was named ‘Hwawang’ and had a high head rice ratio and good eating quality. The culm length of ‘Hwawang’ averaged 62 cm during the yield trials and was 10 cm shorter than that of ‘Keumo’. The number of spikelets per panicle of ‘Hwawang’ was significantly lower than that of ‘Keumo’, but the number of tillers per hill was higher. This variety showed resistance to bacterial blight disease but was moderately susceptible to both leaf and neck blast. The milled rice yield of ‘Hwawang’ was 452 kg/10 a at the late transplanting stage of the local adaptability test. Thus, ‘Hwawang’ is well adapted to the rice–cash crop rotation system in the southern plain area. (Registration No. 5106)

Joil’ is a multiple disease resistant early maturing rice cultivar with high grain quality. ‘Joil’ was derived from a single cross between ‘Unbong37’ (cultivar name ‘Unmi’) and ‘HR23156-26-2-3-5’. ‘Unmi’ is an early maturing rice cultivar with high grain quality and resistance to rice blast and stripe virus. ‘HR23156-26-2-3-5’ is an early maturing elite rice line with lodging resistance and cold tolerance. ‘Joil’ was selected through the pedigree method, yield trials, and local adaptability tests. ‘Joil’ was an early maturing rice. The heading date of ‘Joil’ was July 16 in early transplanting cultivation, which was 2 days later than that of ‘Jopyeong’. ‘Joil’ was a lodging resistance rice with a short culm and showed better tolerance to viviparous germination than that of ‘Jopyeong’. ‘Joil’ was a multiple disease resistant rice with resistance against rice blast, bacterial blight, and stripe virus. ‘Joil’ showed higher yield in both early and late-transplanting cultivations than those of the standard rice cultivars ‘Jopyeong’ and ‘Geumo’. ‘Joil’ had enhanced grain quality under high temperature ripening conditions in early transplanting cultivation. The cooked rice had good grain appearance and taste attributes, and this cultivar had a higher head rice ratio than that of ‘Jopyeong’. ‘Joil’, a multiple disease resistant early maturing rice cultivar with high grain quality, would be suitable for early transplanting cultivation in the southern plain area (Registration No. 6792).

Molecular markers of doubled-haploid (DH) and long spike Korean wheat cultivar populations were evaluated to improve the yield potential of Korean wheat breeding programs by improving the tiller numbers. In Korean wheat cultivars, the tiller number was affected more by vernalization (Vrn) and photoperiod (Ppd) than by tiller inhibition gene (tin) and fertile tiller inhibition gene (ftin). Also, it was negatively correlated with the yield. In DH lines, the tiller number was significantly affected by neither the tiller inhibition genes nor Vrn and Ppd. Additionally, it was not significantly correlated with the yield. However, the adaptability of both SSR markers, Xgpw2206 and Xgwm247, was higher in the DH lines than in the other populations. In the long spike population, the tiller number differed according to the Ppd-D1 allele, affecting the yield. In this study, genes and molecular markers related to the tiller number, as described in previous studies, might be difficult to use to evaluate the tiller number and yield of the Korean wheat population. Hence, continuous study is necessary to develop molecular markers suitable for improving the tiller number and yield of Korean wheat cultivars.

To enhance rice yield and diversify grain quality of Korean japonica rice, we developed japonica rice line with long and spindle-shaped grain. Korean japonica rice cultivars have narrow genetic background of grain size and shape. Most of cultivars show medium-short and semi-round grain. To diversify the genetic background for grain, we developed Jeonju625, japonica rice line with long and spindle-shaped grain, derived from a cross between DSG79, the breeding material with extra-long and spindle-shaped grain, and Boramchan, japonica super high-yielding cultivar with medium-short and semi-round grain. Jeonju625 had GW2gs3qSW5+qGL3 allele type for grain-related genes, which conferred extra-long and spindle-shaped grain. The grain length and ratio of length to width of brown rice of Jeonju625 was 7.06 mm and 2.72, respectively. Jeonju625 was improved the deteriorated traits of DGS79, very late heading, long culm, long awn, droopy flag leaves, and susceptibility to lodging, by strong selection pressure focused on field breeding. The milled rice yield of Jeonju625 was 559 kg/10a, which was similar level of Boramchan (552 kg/10a) and 29% enhanced yield compared to DSG79. Jeonju625 had suitable characteristics for cooked rice. Jeongju625 showed lower protein contents and better glossiness and palatability of cooked rice than Boramchan and Hanareum2. Elite japonica rice line, Jeonju625, with extra-long and spindle-shaped grain showed good characteristics for rice yield and grain quality. Jeonju625 could be utilized practical cultivar and breeding material for enhancing rice yield and diversifying grain quality.

‘Jungmo1045’, a multi-resistant japonica rice cultivar developed from a cross between ‘Hanggeumnuri’ having a good eating-quality and high yield and ‘SR30071’ having brown planthopper (BPH) resistance, was developed by the rice breeding team of NICS, RDA in 2015. This cultivar has about 121 days growth duration from transplanting to harvesting in west-southern coast, Honam and Youngnam plain of Korea. It has 73cm culm length and 22cm panicle length. In reaction to biotic and abiotic stresses, it shows resistance to bacterial blight pathogen races from K1 to K3, stripe virus and brown planthopper. The milled rice of ‘Jungmo1045’ exhibits translucent, relatively clear non-glutinous endosperm and medium short grain. It has good palatability of cooked rice compared with ‘Nampyeongbyeo’. The milled rice yield performance of this variety is about 5.74 MT/ha in local adaptability test for three years. ‘Junngmo1045’ would be useful genetic resources for multi-resistance breeding program against disease and insect and eco-friendly cultivation.

To diversify the grain size and shape of japonica rice, we developed the Breeding Materials with Diverse Grain Size and Shape (BM_DGS) and characterized the grain and yield-related traits. We used the donor parents Jizi1560 and Jizi1581, japonica germplasm with extremely large grain size. Four cross combinations between the each donor parents and Korean high yielding japonica rice cultivars, Deuraechan and Boramchan, were constructed and anther culture method was applied. Among 290 doubled haploid lines, we selected 91 elite lines with diverse grain size and shape and designated to the BM_DGS. The grain size and shape of BM_DGS exhibited beyond the characteristics of previously developed Korean rice cultivars. The alleles of major grain-related genes, GW2, GS3, and qSW5, in BM_DGS showed two types, wild type or loss-of-function mutant type. The loss-of-function mutant alleles, gw2, gs3, and qSw5, had an effect on increasing grain size. The phenotypic variation of grain length was mostly controlled by GS3 alleles, and grain width and thickness were influenced by the combinations of GW2 and qSW5 alleles. 1,000-grain weight was determined by the combinations of GW2, GS3, and qSW5. The grain-related genes influenced the phenotypic variation of yield-related traits. The result of this study could be useful to elucidate the relationship between the grain-related genes and agronomic traits. And the BM_DGS are being utilized in the breeding programs to diversify the grain size and shape in japonica rice.

‘Manbaek’ is a bacterial blight resistant mid-late maturing rice cultivar with high grain quality. ‘Manbeak’ was derived from anther culture using the backcross combination, Hopum*2/SR30075. ‘Hopum’ is a mid-late maturing rice cultivar with high grain quality and ‘SR30075’ is a pyramid line carrying three bacterial blight resistance genes. ‘Manbaek’ was selected through the pedigree method, yield trials, and local adaptability tests. ‘Manbeak’ carrying two bacterial blight resistance gene Xa3 and xa5 showed high-level and broad-spectrum resistance against bacterial blight. ‘Manbaek’ was resistant to K3a, mostly virulent race in Korea, and exhibited resistance reaction against 16 Korean bacterial blight isolates. ‘Manbaek’ was a mid-late maturing rice. The heading date of ‘Manbaek’ was August 19th, which was 5 days later than that of ‘Nampyeong’. Manbaek’ was a lodging-tolerant rice with short culm and dark green leaf. Due to the low viviparous germination, ‘Manbaek’ could be a useful material to prevent pre-harvest sprouting. ‘Mabeak’ was resistant to bacterial blight and rice stripe virus, but susceptible to other virus diseases and insect pests. The yield of ‘Manbaek’ was similar to ‘Nampyeong’. ‘Manbaek’ showed excellent grain appearance and good tastes of cooked rice, so that it could contribute to improving the quality of bacterial blight resistant cultivars. ‘Manbaek’, bacterial blight resistant cultivar with high grain quality, is suitable for the cultivation at bacterial blight prone area and has been utilized in the breeding programs for enhancing the resistance against bacterial blight (Registration No. 6069).