Ji-Yoon Lee

‘Geumgang 1’ (Milyang307) is a high-yielding Tongil-type rice cultivar developed by the National Institute of Crop Science, RDA, in 2017 for the rice processing and baking industries. It was derived from a cross between ‘Dasan1’ and ‘Geumgangbyeo’. The cultivar heading date is on August 14 in the southern plain region of Korea and is classified as medium-late maturing. It has a culm length of 74 cm, 13 panicles per hill, 142 spikelets per panicle, a ripened grain ratio of 78.6%, and a 1,000-grain weight of 23.1 g. ‘Geumgang 1’ is resistant to leaf blast, bacterial blight (K1-K3a), and rice stripe virus but susceptible to brown planthopper. In regional adaptability tests (2015-2017) at three locations, it produced an average milled rice yield of 8.17 MT/ha, the highest recorded among Korean rice cultivars and was 23% higher than the yield of ‘Dasan’. With 19.0% amylose and flour properties similar to those of japonica rice, it is well suited as a wheat flour substitute for bakery products and is recommended for single-cropping plains in southern Korea (Registration No. 7686).

‘Amimyeon’ (Milyang355) is a new Tongil-type rice cultivar developed by NICS, RDA, in 2022, to improve processing suitability and cost competitiveness in the rice noodle industry. Derived from a cross between ‘Milyang288’ and ‘Bukkyeong2012-2,’ it is medium-late maturing ecotype with an average heading date of August 13. It has a culm length of 81 cm, 122 spikelets per panicle, a ripening ratio of 85.2%, and distinct medium-long grains (length-to-width ratio of 2.77). ‘Amimyeon’ exhibits strong resistance to leaf blast and rice stripe virus, with a very low viviparous germination rate (0.2%). Physicochemical analyses revealed high amylose content (26.7%), 8.1% protein content, and a Jasmine85-like aromatic profile. Cooked pasta and noodles made from ‘Amimyeon’ exhibited superior springiness, cohesiveness, and tensile strength compared with commercial products. Its average milled rice yield was 7.24 MT/ha (724 kg/10a), revealing a 4% increase over ‘Dasan’. Thus, ‘Amimyeon’ is highly recommended for plain regions in South Korea as a premium processing material (Registration No. 10644).

Rice paddies are a major source of methane emissions. To meet the food demand of the growing population and to cope with global warming, reducing greenhouse gases and enhancing yields are critical. Here we demonstrate that a loss-of-function rice allele, gs3, mitigates methane emissions from methanogens by allocating more photosynthates to the grain and less to the root and increases yield by enlarging grain size and weight.

Ice cream consumption has increased over the years. In this study, we investigated the potential of using rice varieties with varying amylose contents for ice cream production. We analyzed the physical and chemical properties and sensory quality characteristics (appearance, taste, texture, chewiness, aroma, and rice flavor) of rice-based ice cream made from five varieties with low and high amylose levels. To make the ice cream, we ground rice into a fine powder and combined it with skim milk powder, butter, sugar, glycerin esters of fatty acids, locust bean gum, and water to form a gelatinized mixture. This mixture was then aged, frozen, and hardened. The ice cream’s key quality characteristics, such as viscosity (2170–25,030 cP), hardness (4.27–49.55 N cm⁻²), and overrun (17.95–46.99%), showed a wide range. Ice cream made from Saemimyeon (high amylose content rice variety) exhibited the highest hardness value (49.55 N cm⁻²) among the varieties tested, but had relatively low viscosity (4030 cP), overrun (17.95%), and drip-through (0.75 g/min) values. These findings suggest that rice varieties with different amylose contents are suitable for making ice cream and have the potential to expand the rice processing market and increase its value.

Bakanae disease caused by Fusarium fujikuroi causes crop failure and yield losses in the majority of rice-growing countries. In this study, we employed a joint strategy quantitative trait locus (QTL) mapping–Genome-Wide Association Study (GWAS) to investigate novel genetic loci associated with Bakanae disease resistance using a population of 143 BC₁F₈ RILs derived from a cross between Ilpum × Tung Tin Wan Hien1. The phenotypic data from the bioassay and the genotypic data generated using a DNA chip were utilized to perform QTL mapping and GWAS study. Our results identified a novel genetic locus qBK4^T associated with Bakanae disease resistance, which was mapped on chromosome 4 and flanked by AX-116847364 (33.12 Mbp) and AX-115752415 (33.44 Mbp) markers covering a region of 324kbp. There were 34 genes in this region including Os04g55920 (encoding a zinc-finger protein, OsJAZ1), Os04g55970 (encoding AP2-like ethylene-responsive transcription factor), etc. This study proposes qBK4^T as a novel locus for Bakanae disease resistance. The identification of qBK4^T and its flanking marker information could be useful for marker-assisted breeding and functional characterization of resistance genes against bakanae disease.

The physicochemical characteristics of five types of rice-based home meal replacement (HMR) products (instant rice, doshirak, kimbab, frozen fried rice, and freeze-dried rice) were measured before and after microwave cooking, and principal component analysis (PCA) was performed. HMR products contained grains from 8.42 to 8.72 mm before and after the microwave cooking. The amylose content and water absorption index (WAI) ranged from 20.10-23.15% and 0.50-2.87%, respectively. Frozen fried rice showed high amylose content but low WAI, and dry rice showed low amylose content but high WAI. There was a change in the moisture content of freeze-dried rice: moisture increased from 1.3 to 60.3% after cooking. The rehydration rate of freeze-dried rice was about twice higher than that of other HMR products, while instant rice showed a low rehydration rate. The texture profile's hardness and cohesiveness respectively were 306.1 g/cm2 and 47.9% before cooking, but 209.6 g/cm2 and 66.0% after cooking. The lightness value decreased from 72.5 to 68.9 after the microwave cooking, while there was little change in the lightness value of instant rice, and that of the frozen fried rice decreased. PCA revealed that, microwave cooking apparently affected WAI and rehydration rate in the freeze-dried rice yellowness in the frozen fried rice, and stickiness and lightness in the instant rice, respectively.

Nitrogen (N) is a gas and the fifth most abundant element naturally found in the atmosphere. N’s role in agriculture and plant metabolism has been widely investigated for decades, and extensive information regarding this subject is available. However, the advent of sequencing technology and the advances in plant biotechnology, coupled with the growing interest in functional genomics-related studies and the various environmental challenges, have paved novel paths to rediscovering the fundamentals of N and its dynamics in physiological and biological processes, as well as biochemical reactions under both normal and stress conditions. This work provides a comprehensive review on multiple facets of N and N-containing compounds in plants disseminated in the literature to better appreciate N in its multiple dimensions. Here, some of the ancient but fundamental aspects of N are revived and the advances in our understanding of N in the metabolism of plants is portrayed. It is established that N is indispensable for achieving high plant productivity and fitness. However, the use of N-rich fertilizers in relatively higher amounts negatively affects the environment. Therefore, a paradigm shift is important to shape to the future use of N-rich fertilizers in crop production and their contribution to the current global greenhouse gases (GHGs) budget would help tackle current global environmental challenges toward a sustainable agriculture.

In recent years, many rice varieties with improved processing quality have been developed to promote domestic rice consumption along with the increasing preference for plant-based food and by-products. This study aimed to assess the quality characteristics of rice milk using a set of rice varieties, including saeilmi (normal brown rice, NBR; and normal white rice, NWR), milyang355 (aromatic brown rice, ABR; and aromatic white rice, AWR) and milyang365 (pigment brown rice, PBR). Among these, the amylose content ranged from 5.13-23.50%, and the highest crude protein content was recorded in ABR (7.95%). In addition, brown rice showed a higher initial pasting temperature than did white rice; however, its viscosity properties were relatively low. Our data showed that the soluble solid content of rice milk was 6.5-7.7 °Brix, and viscosity ranged from 2.8-4.8 cP. Reducing sugar and free sugar content was high in AWR (p<0.05). AWR had a high L* value, while the particle size and normalized turbidity were lower than those of ABR, depending on the degree of milling. Regarding sensory evaluation, ABR was the most preferred and obtained the highest scores for rice flavor, taste, and texture. In summary, the study findings provide strong evidence that ABR presents the best processing qualities and could preferably be used for plant-based rice milk making.

We investigated the germination rate, color values, physicochemical properties, antioxidant capacity, and amino acid content of germinated brown rice varieties (milyang356, nampyeong, and dasan), and their statistical correlation were analyzed. Milyang356 rice was characterized by the highest germination percentage and total color difference value (3.89) at 24 h. In all varieties, the amylose and crude protein content increased on the 1st day of germination but decreased over time (p<0.05). The paste viscosity value significantly decreased over time in all varieties. DPPH and ABTS scavenging activities decreased or increase over time depending on the variety. By contrast, the total phenol and flavonoid content increased with time in all varieties. Furthermore, the total free amino acid and GABA content increased gradually with the germination time. The essential amino acid content was highest on day 3 of germination in milyang356 (276.9 mg/100 g) and dasan varieties (344.1 mg/100 g). The total phenol content showed a negative correlation with L* value (r=−0.778) and a strong positive correlation with ΔE (r=0.927). Considering its paste viscosity, and high essential amino acid and GABA content, we conclude that germinated brown rice milyang356 is suitable as a functional medical material, such as a health supplement.

The National Institute of Crop Science, Rural Development Administration (RDA) of Korea is presently developing new rice varieties suitable for producing Western rice-based foods, such as risotto, a well-known Italian-style product. The study considered different milled rice from five Tongil-type and six Japonica-type varieties. Besides the biometric properties, cooking behaviour, starch properties, and in vitro digestibility of Korean rice samples were compared with those of the ‘Carnaroli’ Italian variety. The physicochemical traits of the Korean varieties extended over a vast range; the amylose content stood out (from 13.0 to 41.7%), influencing the hardness and stickiness of cooked samples, and their starch digestibility. Although none of the Korean varieties seemed to guarantee cooking performances for risotto similar to the ‘Carnaroli’ one, ‘Saemimyeon’ and ‘Shingil’ cvs were judged the best for this purpose up-to-now.