To improve resistance to planthoppers and viral diseases, a new rice cultivar named ‘Drimi9ho’ was established. The F₁ population, derived from a cross between ‘Cheongcheong’ and ‘Nagdong’, was subjected to anther culture. Subsequent generations were advanced in the field under high selection pressure for agronomic traits and disease resistance. Ultimately, the line ‘CNDH-AC63-2-2-2-1’ was selected through the pedigree method and was named ‘Drimi9ho’ after undergoing yield trials and local adaptability tests. ‘Drimi9ho’ has a heading date of August 13, which corresponds to 107 days after sowing, making it a mid-late maturing variety that heads 3 d later than ‘Cheongcheong’. The culm length of ‘Drimi9ho’ is 57.3 cm, which is 15 cm shorter than that of ‘Cheongcheong’. This reduced culm length contributes to improved tolerance to field lodging. In addition, ‘Drimi9ho’ exhibits acquired resistance to rice black-streaked dwarf virus through introgression from ‘Nagdong’. Compared to ‘Cheongcheong’, ‘Drimi9ho’ shows lower protein content and higher amylose content, which resulted in a higher score for cooked-rice palatability. ‘Drimi9ho’ shows improved milling performance compared to ‘Cheongcheong’. The 1,000-grain weight of ‘Drimi9ho’ is 22.12±0.8 g, which is heavier than that of ‘Cheongcheong’ (19.42±0.8 g). The milled rice yield of ‘Drimi9ho’ is 546.6±3.8 kg/10a, representing a 4.7% increase compared to ‘Cheongcheong’ (522.2±5.8 kg/10a). However, ‘Drimi9ho’ is resistant only to bacterial leaf blight race K₁; thus, timely disease management is required to control other races such as K₂, K₃, and K_3a (Registration No. 10610).

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.

Since iron (Fe) and zinc (Zn) are essential micronutrients for human immunity and metabolic activities, it is important to biofortify major food crops such as wheat and improve the bioavailability of Fe and Zn. In this review, we focused on analyzing studies conducted to identify and evaluate QTLs, genes, and associated molecular markers related to Fe and Zn content in wheat, their absorption mechanisms, and bioavailability in terms of genetics and breeding. Because bread wheat has a limited Fe and Zn content in its grains, many studies have used wild, synthetic, or mutant wheat resources with high Fe and Zn contents. Many studies have been conducted to characterize related genes, of which Gpc-B1 is the major gene that increases the final content of Fe, Zn, and protein in association with an Gpc-B1 increase in Fe uptake and regulate Zip and YSL expression. Research determining the appropriate phytic acid content and increasing phytase activity to improve bioavailability was also highlighted.

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).

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).

Breeders typically use core collections of a specific trait or core collections selected by a few genotypes to efficiently select breeding materials or to study functional genes. As a result, many accessions have been deemed redundant or duplicated and are no longer considered for use. This study aimed to investigate the agronomical characteristics and genetic diversity of 1,514 previously unused and unstudied wheat germplasms and to confirm their value as breeding materials using population structure analysis. The performance of these wheat germplasms was compared with that of 8,878 wheat breeding materials and 72 known Korean wheat cultivars. The results of agronomic trait diversity comparison showed that the germplasm populations used for breeding research did not completely encompass the unused germplasm populations. The agronomic traits of wheat germplasms varied greatly. ANOVA and PCA results revealed the greatest differences in growth habits (CV=0.339), panicle length (CV=0.330), and awn length (CV=0.296). To accurately assess the value of unused wheat germplasms as breeding materials, 106 SSR markers were extracted from the analysis of four representative Korean cultivars: Geuru, Geumgang, Uri, and Jokyoung. Among these, 24 SSR markers were chosen, and 129 wheat resources were subjected to population structure analysis, which revealed five subpopulations. Most of the 34 germplasms that originated in Korea were distributed in subpopulation 1 (18 accessions, 52.9%) and subpopulation 4 (12 accessions, 35.3%). Subgroups 2, 3, and 5 differed significantly in agronomic traits and genotypes, indicating their potential as breeding materials. The findings of this study could serve as a foundation for breeders and aid in the discovery and utilization of new wheat breeding materials.

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).

Brown planthopper (BPH, Nilaparvata lugens Stal) is a major agricultural pest that plays a key role in reducing rice yield. Rapid climate change has emphasized the necessity of cultivating multi-resistant cultivar rather than cultivar with single-resistance to specific pests. Accordingly, the Plant Molecular Breeding Laboratory of the Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu 41566, Korea developed the ‘Drimi 1ho’ rice cultivar with enhanced resistance to blast and bacterial blight as well as BPH breeding in 2008. In order to breed ‘Drimi 1ho’, ‘Samgang’ and ‘Nagdong’ were crossed and backcrossed with ‘Junam’, after which the pedigree breeding method was applied. Finally, ‘Drimi 1ho’ was selected through analysis of resistance to insect and viral disease, yield, and grain quality. ‘Drimi1ho’ is strongly resistant to BPH and has a wide range of resistance to pests. ‘Drimi 1ho’ is also resistant to blast and bacterial blight (K₁, K₂, K₃), which occurs most frequently and causes serious damage to crops in the Republic of Korea. The agricultural characteristics of 'Drimi 1ho' were similar or improved from 'Junam'. In particular, ‘Junam’ is susceptible to BPH and bacterial blight. ‘Drimi 1ho’ made up for the shortcomings of ‘Junam’ with acquired strong and broad-spectrum resistance. Finally, ‘Drimi 1ho’ had a yield of 563 kg/10 a under normal cultivation and can thus be an adaptable cultivar in south mid-mountainous areas in the Republic of Korea (Registration No. 3685).

This study aimed to develop an agarose gel-based multiplex PCR assay using sequence-tagged site (STS) and simple sequence repeat (SSR) markers that can differentiate Korean wheat cultivars. Forty-nine Korean wheat cultivars were primarily classified based on seed coat color into red (36) and white (13) groups. Red wheat cultivars were further differentiated by three multiplex PCRs using molecular markers for Ppo-A1/Vrn-D1a/Rht-B1b, Glu-A3ac/TaCwi-A1b/Lr34, and Glu-A1ac/Glu-B1b/KWSM003/TaSE96. Similarly, white wheat cultivars were further differentiated using two multiplex PCRs using the molecular markers for Ppo-A1/Vrn-D1a/Pina-D1a and Ppo-B1/Glu-B3h. A multiplex PCR assay using molecular markers for Glu-A1b/Glu-D1d/Wx-B1 was developed to differentiate four Korean wheat cultivars used as government certified seeds: Baekkang, Hwanggeumal, Keumkang, and Saekeumkang. A multiplex PCR assay using molecular markers for Glu-B3h and Pin-D1a was used for colored wheat cultivars, Arijinheuk, Ariheuk, and Chinese colored wheat. The multiplex PCR assays developed in this study can provide useful molecular tools for differentiating Korean wheat cultivars, developing wheat seed management systems, and guaranteeing wheat seeds in Korea.

An advanced F₈ population was derived from a cross between the hard wheat cultivar “Keumkang” carrying Pinb-D1b and the soft wheat cultivar “Olgeuru” carrying Pinb-D1a. A breeding line named “Hetero”, which exhibited the heterozygous-like Pinb-D1a/Pinb-D1b genotype, was selected by sequence analysis and KASP (Kompetitive Allele Specific PCR) assay. Physicochemical and processing characteristics of flour were tested in the Hetero line and compared with the two parental cultivars for two years. Hetero display a Glu-1 composition similar to Keumkang and a Glu-3 composition intermediate between Keumkang and Olgeuru. Contrary to the expectation that Hetero carrying the Pinb-D1a/Pinb-D1b genotype would exhibit an intermediate phenotype between the two parents, its overall flour physicochemical characteristics were more similar to Keumkang than to Olgeuru. The flour yield of Hetero (71.6%) was lower than that of Keumkang (74.5%). However, the flour particle size (73.3 μm) and damaged starch content (4.6%) of Hetero were similar to those of Keumkang (71.9 μm and 4.5%). The protein content (16.5%) and sodium dodecyl sulfate-sedimentation volume (72.8 mL) of Hetero were higher than those of Keumkang (14.0% and 57.5 mL) and Olgeuru (11.4% and 45.5 mL). The mixograph water absorption (68.7%) and mixing tolerance (17.7 mm) values of Hetero were higher than those of Keumkang (65.6% and 15.9 mm) with the same mixing time of 3.9 min. The bread loaf volume of Hetero was lower than that of Keumkang (866.7 vs. 894.7 mL). The cooked noodles hardness of Hetero was higher than that of Keumkang (5.9 vs. 4.7 N).

The
objective
of this study was to identify quantitative trait loci (QTL) of spike length by association analysis with 94 doubled haploid wheat lines derived from Keumkang and Olgeuru. Days to heading date, culm length, spike length, and kernels per spike were evaluated in 2017 and 2018 in upland conditions. Culm length and spike length were biased short culm length and spike length (skewness=0.2 and 1.5, respectively). Kernel number per spike was biased low kernel number per spike (skewness=0.8). A genetic map was constructed with 170 microsatellite marker loci. One QTL was detected for spike length. The QTL on chromosome 4A, qSL-1 was detected by Xwmc283 and Xbarc327 explained 44.3% of the phenotypic variation. The QTL was applied to validate the relationship between genotypes of QTL and 29 Korean wheat cultivars grown for nine years under upland conditions. Korean wheat cultivars were classified into 5 types based on the combination of the two SSR markers. In Korean wheat cultivars, genotype b at Xbarc327, which was homozygous to Keumkang, had a shorter spike length (7.48 cm) than genotype c, which was different from the genotypes of Keumkang and Olgeuru, (8.45 cm). The two Korean wheat cultivars with genotypes ac at Xwmc283 and Xbarc327 had longer spike length (8.45 cm) than genotypes ba and bb (<7.42 cm).

Recently, several attempts have been undertaken to develop breeding technologies by combining new biotechnologies. Gene-editing technology is currently one of the most interesting areas. The plant breeding methods using this technique have the advantage of greatly improved accuracy and efficiency of the plant genetic correction compared with conventional breeding methods, which has raised expectations for the useful application of this technology as a cutting-edge breeding technology. Although not all countries around the world currently have established appropriate regulation policies on crops developed with gene-editing technology, the number of cases in which GMO regulations are not applied on a case-by-case basis according to the scientific background is growing. However, Korea has not yet established policies on which criteria should be applied to crops generated from the application of gene-editing technology. As the number of cases of crop development and commercialization using gene-editing technology is expected to increase in the near future, it will be necessary to prepare reasonable policies to support developers and seed industries in Korea to ensure harmonization with international regulatory policy trends.

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 compared disease incidence rate and phyllosphere microbial community between drought resistance transgenic rice (Agb0103) and non-transgenic Ilmi (NGM) during 2011-2014 to examine an environmental risk assessment of drought resistance transgenic rice (Agb0103). As the results, major diseases such as sheath blight, brown spot, leaf blast and false smut were occurred, however, there were no significant disease incidence rate between Agb0103 and NGM. As the results of counting bacterial and fungal viable cell, the colonies were increased or decreased which affected by environmental conditions, however there were no differences between Agb0103 and NGM. Also unweighted pair-group method with arithmetic averaging (UPGMA) analysis based on polymerase chain reaction with denaturing gel electrophoresis (PCR-DGGE) revealed that DGGE band pattern of bacterial and fungal communities were clustered by each month and there were no differences between Agb0103 and NGM. Furthermore, isolated casual agents causing sheath blight and brown spot were collected from Agb0103 and NGM, and they revealed that each of pathogens were no differences in morphology and pathogenicity. Therefore, our results suggested that Agb0103 showed no differences in disease incidence rate, characteristic of pathogens and phyllosphere community with NGM. In this way, it can be assumed that transgenic rice Agb0103 could not influence phyllosphere microorganism community and environmental conditions.