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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.

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

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

The physicochemical and structural characteristics of high­yield, tongil­type mirchal glutinous rice, Milyang 328 (hereafter referred to as mirchal), were compared to those of a set of well-characterized glutinous rice varieties i.e., baegokchal, dongjinchal, and sinseonchal. The results revealed that mirchal exhibited the highest crude protein content (8.47%), water binding capacity (209.00%), and swelling power (55.82 g/g) under long term soaking. Analysis under identical conditions revealed that mirchal rice flour presented the minimum mean and median particle diameters of 50.54 μm and 22.72 μm, respectively, among the tested varieties. Furthermore, the particle diameter and onset temperature (To, 57.15°C) under these conditions were significantly lower than those under other conditions. The crystalline fraction of glutinous rice flour exhibited an A-type structure, irrespective of the soaking time. Mirchal exhibited the highest breakdown viscosity of 1,416.0 cP under short term soaking. The branch chain length distribution of the amylopectin A chain in the glutinous rice flours was arranged in the following sequence: baegokchal (30.82%) > mirchal (29.59%) > dongjinchal (28.74%) > sinseonchal (27.10%). The length distribution of the B1 chain in the glutious rice flours was arranged in the following sequence: dongjinchal (47.85%) > mirchal (47.17%) > baegokchal (45.83%) > sinseonchal (44.47%). Thus, this study revealed that mirchal possessed optimal processing characteristics owing to its high swelling power and excellent physicochemical properties, therby facilitating its application in the synthesis of yukwa and food processing materials.

In this study, we fermented ‘Makgeolli’ prepared using brown or white rice from ‘Mirchal’ for seven days to investigate the differences in their quality characteristics. Moreover, the physicochemical characteristics and antioxidant activities of ‘Makgeolli’ were assessed using principal component analysis (PCA). From the second day of fermentation, brown rice ‘Makgeolli’ exhibited a higher alcohol content (7.00%) than that of white rice ‘Makgeolli’ (3.60%). Additionally, the total polyphenol contents and antioxidant activities increased with the duration of fermentation (p

In the tropics (Southeast Asian countries), indica rice is more common than japonica. Japonica rice is mainly cultivated in temperate regions, including Korea, Japan, and China (northeast regions) due to its poor adaptation to tropical areas. To develop tropically-adapted high-yielding japonica rice, breeders should overcome the challenges, including extremely early flowering, low biomass accumulation, and inferior panicle traits. This study investigated 180 F9 recombinant inbred lines (RILs) developed from a cross between Ilpum (temperate japonica) and Zenith (indica) as a case population to identify quantitative trait loci (QTLs) that influence the said traits. Here we identified two major QTLs, qHD6-SD and qHD6- LD, conferring days to heading under short day (SD) and long day (LD) conditions, respectively. Finer mapping revealed that both qHD6-SD and qHD6-LD located in the similar 98 kb region harbored the Hd1 gene. Days to heading in the RILs harboring the Zenith allele type of qHD6-SD under SD conditions were significantly longer than those in the RILs harboring the Ilpum allele type. On the contrary, days to heading in the RILs harboring the Zenith allele type of qHD6-SD under LD conditions were significantly shorter than those in the RILs harboring the Ilpum allele type. This bi-functionality of qHD6-SD upon heading strongly support the claim that both qHD6-SD and qHD6-LD might be the Hd1 gene. Our findings further support the claim that the functional allele type of Hd1 gene delays long-day heading and promotes extremely early short-day heading. Therefore, a non-functional Hd1 type is critical to tropical adaptation of japonica rice since it delays the heading date, which is essential to attain prolonged vegetative state in order to achieve optimum biomass, increased spikelet number, and grain filling capacity.

In the environment, bacteria show close association, such as interspecies interaction, with other bacteria as well as host organisms. The type VI secretion system (T6SS) in gram‐negative bacteria is involved in bacterial competition or virulence. The plant pathogen Burkholderia glumae BGR1, causing bacterial panicle blight in rice, has four T6SS gene clusters. The presence of at least one T6SS gene cluster in an organism indicates its distinct role, like in the bacterial and eukaryotic cell targeting system. In this study, deletion mutants targeting four tssD genes, which encode the main component of T6SS needle formation, were constructed to functionally dissect the four T6SSs in B. glumae BGR1. We found that both T6SS group_4 and group_5, belonging to the eukaryotic targeting system, act independently as bacterial virulence factors toward host plants. In contrast, T6SS group_1 is involved in bacterial competition by exerting antibacterial effects. The Δ tssD1 mutant lost the antibacterial effect of T6SS group_1. The ΔtssD1 mutant showed similar virulence as the wild‐type BGR1 in rice because the ΔtssD1 mutant, like the wild‐type BGR1, still has key virulence factors such as toxin production towards rice. However, metagenomic analysis showed different bacterial communities in rice infected with the ΔtssD1 mutant compared to wild‐type BGR1. In particular, the T6SS group_1 controls endophytic plant‐associated bacteria such as Luteibacter and Dyella in rice plants and may have an advantage in competing with endophytic plant‐associated bacteria for settlement inside rice plants in the environment. Thus, B. glumae BGR1 causes disease using T6SSs with functionally distinct roles., T6SS group_4 and T6SS group_5 affect the pathogenicity of Burkholderia glumae BGR1 as a completely independent eukaryotic targeting system, whereas T6SS group_1 is involved in bacterial competition by an antibacterial effect.

Temperate japonica rice is mainly cultivated in temperate regions. Many temperate japonica varieties have a superior grain quality that is preferred in Northeast Asian countries such as Japan, Korea, and China. The changes in consumers’ preferences in Southeast Asia and Western countries has contributed to increasing the demand for temperate japonica. Most temperate japonica varieties developed in temperate regions typically exhibit extra-early flowering under the short-day conditions in the tropics, which usually results in severely reduced yields. Since 1992, we have been developing temperate japonica varieties that can adapt to tropical environments to meet the increasing demand for temperate japonica rice, having released six varieties in the Philippines. Especially, the yield of one of the temperate japonica varieties, Japonica 7, was comparable to the yields of leading indica varieties in the Philippines. Here, we discuss the current breeding initiatives and future plans for the development of tropical-region-bred temperate japonica rice.

Background: Bakanae disease is a fungal disease of rice (Oryza sativa L.) caused by the pathogen Gibberella fujikuroi (also known as Fusarium fujikuroi). Recently the disease incidence has increased in several Asian countries and continues to spread throughout the world. No rice varieties have been developed yet to be completely resistant to this disease. With increasing need to identify various genetic resources to impart resistance to local elite varieties, this study was carried out to identify novel quantitative trait loci (QTLs) from an indica variety Zenith. Results: We performed a QTL mapping using 180 F2:9 recombinant inbred lines (RILs) derived from a cross between the resistant variety, Zenith, and the susceptible variety, Ilpum. A primary QTL study using the genotypes and phenotypes of the RILs indicated that the locus qBK1z conferring bakanae disease resistance from the Zenith was located in a 2.8 Mb region bordered by the two SSR markers, RM1331 and RM3530 on chromosome 1. The log of odds (LOD) score of qBK1z was 13.43, accounting for 30.9% of the total phenotypic variation. A finer localization of qBK1z was delimited at an approximate 730 kb interval in the physical map between Chr01_1435908 (1.43 Mbp) and RM10116 (2.16 Mbp).Conclusion: The development of a rice variety with a higher level of resistance against bakanae disease is a major challenge in many rice growing countries. Introducing qBK1z or pyramiding with other previously identified QTLs could provide effective genetic control of bakanae disease in rice.

Bakanae disease is a fungal disease of rice (Oryza sativa L.) caused by the pathogen Gibberella fujikuroi (also known as Fusarium fujikuroi). Recently the disease incidence has increased in several Asian countries and continues to spread throughout the world. No rice varieties have been developed yet to be completely resistant to this disease. With increasing need to identify various genetic resources to impart resistance to local elite varieties, this study was carried out to identify novel quantitative trait loci (QTLs) from an indica variety Zenith. We performed a QTL mapping using 180 F2:9 recombinant inbred lines (RILs) derived from a cross between the resistant variety, Zenith, and the susceptible variety, Ilpum. A primary QTL study using the genotypes and phenotypes of the RILs indicated that the locus qBK1z conferring bakanae disease resistance from the Zenith was located in a 2.8 Mb region bordered by the two SSR markers, RM1331 and RM3530 on chromosome 1.The log of odds (LOD) score of qBK1z was 13.43, accounting for 30.9% of the total phenotypic variation. A finer localization of qBK1z was delimited at an approximate 730 kb interval in the physical map between Chr01_1435908 (1.43 Mbp) and RM10116 (2.16 Mbp). The development of a rice variety with a higher level of resistance against bakanae disease is a major challenge in many rice growing countries. Introducing qBK1z or pyramiding with other previously identified QTLs could provide effective genetic control of bakanae disease in rice.

Background Bakanae disease is an important fungal disease caused by Gibberella fujikuroi. Incidence of rice bakanae disease creates serious problems in the foremost rice growing countries, and no rice variety has been found to be completely resistant to this disease. However, breeding rice varieties resistant to bakanae disease may be a cost-saving solution preferable to the application of fungicides. In this study, we aimed to determine the exact position and the candidate gene for qBK1, a major resistant quantitative trait locus (QTLs) for bakanae disease. Results The genotypes/phenotypes of recombinants selected from backcrossed recombinant inbred lines of two rice varieties, Shingwang (resistant) and Ilpum (susceptible), indicated that the locus qBK1, conferring resistance to bakanae disease in Shingwang, was delimited to a 35-kb interval delimited by InDel 18 (23.637 Mbp) and InDel 19–14 (23.672 Mbp). Sequence analysis of this 35-kb region revealed four candidate genes, LOC_Os01g41770, LOC_Os01g41780, LOC_Os01g41790, and LOC_Os01g41800. There were many non-synonymous SNPs in LOC_Os01g41770 and the transcript of LOC_Os01g41790 was early terminated in Shingwang, whereas there were no differences in both LOC_Os01g41780 and LOC_Os01g41800 sequences between Ilpum and Shingwang. Expression profiling of the four candidate genes showed the up-regulation of LOC_Os01g41770, LOC_Os01g41780, and LOC_Os01g41790 in Ilpum and of LOC_Os01g41800 in Shingwang after inoculation of G. fujikuroi. Conclusion Utilization of marker-assisted selection (MAS) with a precise molecular marker on qBK1 could provide an effective tool for breeding rice varieties resistant to bakanae disease. To our knowledge, this is the first report on fine mapping and candidate gene approaches for identifying the gene for qBK1. Electronic supplementary material The online version of this article (10.1186/s12284-019-0295-9) contains supplementary material, which is available to authorized users.

Table S1. Twelve InDel markers designed by analyzing sequence differences between Nipponbare and 93â 11. Table S2. Seven InDel markers designed by analyzing the differences between Ilpum and Shingwang sequences. Table S3. SNP marker for ARMS PCR designed by analyzing the differences between Ilpum and Shingwang sequences. (DOCX 18 kb)

Bakanae or foot rot disease is a prominent disease of rice caused by Gibberella fujikuroi. This disease may infect rice plants from the pre-emergence stage to the mature stage. In recent years, raising rice seedlings in seed boxes for mechanical transplanting has increased the incidence of many seedling diseases; only a few rice varieties have been reported to exhibit resistance to bakanae disease. In this study, we attempted to identify quantitative trait loci (QTLs) conferring bakanae disease resistance from the highly resistant japonica variety Wonseadaesoo. A primary QTL study using the genotypes/phenotypes of the recombinant inbred lines (RILs) indicated that the locus qBK1 WD conferring resistance to bakanae disease from Wonseadaesoo was located in a 1.59 Mb interval delimited on the physical map between chr01_13542347 (13.54 Mb) and chr01_15132528 (15.13 Mb). The log of odds (LOD) score of qBK1 WD was 8.29, accounting for 20.2% of the total phenotypic variation. We further identified a gene pyramiding effect of two QTLs, qBK WD and previously developed qBK1. The mean proportion of healthy plant for 31 F4 RILs that had no resistance genes was 35.3%, which was similar to that of the susceptible check variety Ilpum. The proportion of healthy plants for the lines with only qBK WD or qBK1 was 66.1% and 55.5%, respectively, which was significantly higher than that of the lines without resistance genes and that of Ilpum. The mean proportion of the healthy plant for 15 F4 RILs harboring both qBK WD and qBK1 was 80.2%, which was significantly higher than that of the lines with only qBK WD or qBK1. Introducing qBK WD or pyramiding the QTLs qBK WD and qBK1 could provide effective tools for breeding rice with bakanae disease resistance. To our knowledge, this is the first report on a gene pyramiding effect that provides higher resistance against bakanae disease.

InDel markers used for the fine mapping of qBK WD . Table S2. Tetra markers used for the fine mapping of qBK WD (DOC 36 kb)

Background Bakanae or foot rot disease is a prominent disease of rice caused by Gibberella fujikuroi. This disease may infect rice plants from the pre-emergence stage to the mature stage. In recent years, raising rice seedlings in seed boxes for mechanical transplanting has increased the incidence of many seedling diseases; only a few rice varieties have been reported to exhibit resistance to bakanae disease. In this study, we attempted to identify quantitative trait loci (QTLs) conferring bakanae disease resistance from the highly resistant japonica variety Wonseadaesoo. Results A primary QTL study using the genotypes/phenotypes of the recombinant inbred lines (RILs) indicated that the locus qBK1WD conferring resistance to bakanae disease from Wonseadaesoo was located in a 1.59 Mb interval delimited on the physical map between chr01_13542347 (13.54 Mb) and chr01_15132528 (15.13 Mb). The log of odds (LOD) score of qBK1WD was 8.29, accounting for 20.2% of the total phenotypic variation. We further identified a gene pyramiding effect of two QTLs, qBKWD and previously developed qBK1. The mean proportion of healthy plant for 31 F4 RILs that had no resistance genes was 35.3%, which was similar to that of the susceptible check variety Ilpum. The proportion of healthy plants for the lines with only qBKWD or qBK1 was 66.1% and 55.5%, respectively, which was significantly higher than that of the lines without resistance genes and that of Ilpum. The mean proportion of the healthy plant for 15 F4 RILs harboring both qBKWD and qBK1 was 80.2%, which was significantly higher than that of the lines with only qBKWD or qBK1. Conclusion Introducing qBKWD or pyramiding the QTLs qBKWD and qBK1 could provide effective tools for breeding rice with bakanae disease resistance. To our knowledge, this is the first report on a gene pyramiding effect that provides higher resistance against bakanae disease. Electronic supplementary material The online version of this article (10.1186/s12284-017-0197-7) contains supplementary material, which is available to authorized users.

Bakanae disease is caused by several species of Fusarium and imposes serious limitations on rice production worldwide. The incidence of this disease is increasing in the top rice-growing countries. Thus, higher resistance to this disease may be a cost-saving solution preferable to the application of fungicides. Here, we developed 168 near-isogenic rice lines (NILs, BC6F4) to locate a QTL for resistance against bakanae disease. The lines were derived from a cross between Shingwang, a highly resistant variety (indica), and Ilpum, a highly susceptible variety (japonica). The 24 markers representing the Shingwang allele in a bakanae disease-resistant NIL, YR24982-9-1 (parental line of the BC6F4 NILs), were located on chromosome 1, 2, 7, 8, 10, 11, and 12. Single marker analysis using an SSR marker, RM9, showed that a major QTL is located on chromosome 1. The QTL explained 65 % of the total phenotype variation in BC6F4 NILs. The major QTL that designated qBK1 was mapped in 520 kb region between RM8144 and RM 11295. The identification of qBK1 and the closely linked SSR marker, RM9, could be useful for improving rice bakanae disease resistance in marker-assisted breeding.