“Baromi2” is an improved resistant early maturing rice variety with floury endosperm, and is suitable for dry milling. This variety was developed in 2019 by crossing “Suweon542,” which is ideal for dry milling, and “Jopyeong” by the rice breeding team at the National Institute of Crop Science, Rural Development Administration. The heading date of “Baromi2” was July 27 in the Honam Plains, 17 d earlier than that of “Seolgaeng.” The culm length of “Baromi2” was 76 cm, which was almost the same as its check variety “Seolgaeng”; additionally, its panicle length, panicle number, and 1,000 grain-weight of brown rice were 23 cm, 11, and 18.4 g, respectively. “Baromi2” showed strong resistance against rice blast, bacterial blight, and stripe virus disease, but was susceptible to dwarf and brown and small brown planthoppers. The milled rice yield of “Baromi2” was approximately 475 kg/10a in the local adaptability test for 3 years in the late planting culture. The grain hardness of “Baromi2” with a floury endosperm was 2 and 3 times lower than that of “Seolgaeng” with opaque endosperm and “Jopyeong” with transparent endosperm, respectively. The rice flour of “Baromi2” exhibited superior physicochemical characteristics with respect to granule size and damaged starch content compared with any other check varieties. These results inferred that “Baromi2” was suitable for dry milling and for the processed rice industry, owing to its lower milling costs and eco-friendly milling methods (Registration No. 9052).

‘Shingil’ was developed as a processing rice for specialization as a rice flour by means of mutation breeding from ‘Hanareum’ MNU (N-methyl N-nitrosourea) treatment. The bulk population was displayed from M₁ to M₆, followed by pedigree methods from M₇, where line selection was carried out based on the amylose content, with opacity in the endosperm. The result was that ‘Milyang317’, which has a somewhat high amylose content as well as a high ratio of starch opacity, was selected and named as ‘Shingil’ in 2017. ‘Shingil’ is a mid-maturing ecotype with a heading date of August 10, showing resistance to both leaf/panicle blast and rice stripe virus (RSV), but susceptibility to Bph. ‘Shingil’ showed a low viviparous germination rate of 5.2%. The yield capacity of ‘Shingil’ was 745kg/10a over two years based on a regional yield test. The amylose content of ‘Shingil’ is 23.4% with the grain showing opacity in most parts of the endosperm, which is caused by the round particle shape, unlike the polygonal shape of ordinary grains. Thus, ‘Shingil’ could be used as a rice flour source in various processing field and dry milling industries where milling costs could be saved (Registration No. 8019).

The rice cultivar ‘Misiru’, which is ideal for rice flour production by dry milling, was developed by the rice breeding team at the National Institute of Crop Science (NICS), Rural Development Administration (RDA), Korea, in 2017 to vitalize the rice processing industry. It is derived from a cross between ‘Daeripbyeo1’ and ‘Seolgaeng’. ‘Misiru’ was grown on a middle plain area by ordinary cultivation methods. The heading date was on August 13, culm length was 85 cm, and there were 12 panicles and 112 spikelets per panicle. The ripened grain ratio was lower than that of ‘Hwaseong’; however, the 1,000 brown rice weight was 30.8 g, about 8 g heavier than that of ‘Hwaseong’. ‘Misiru’ showed medium resistance to blast but susceptibility to bacterial blight, viruses, and insect pests. It was resistant to lodging, whereas pre-harvest sprouting rate and cold tolerance were similar to those of ‘Hwaseong’. The milled rice appeared non-glutinous opaque, with opaque grain rate of 83.7%. The rice grain was soft and starch granules in the endosperm were of spherical type, similar to wheat. The grain contained 6.4% protein and 18.6% amylose (the content of the latter was similar to that in ‘Hwaseong’). However, its milled rice recovery rate was lower than that of ‘Hwaseong’. The average size of dry-milling rice flour was 64.4 μm, and the rate of damaged starch was 5.2%, lower than that of ‘Hwaseong’. ‘Misiru’ milled rice yield was 5.66 MT/ha, 8% higher than the yield potential of ‘Hwaseong’. The cultivar ‘Misiru’ is thus suitable for rice flour production by dry milling (Grant No. 7682).

The ‘Hangaru’ is a rice variety derived from a cross between ‘Seolgaeng’, which is suitable for making rice wine, and ‘Daeripbyeo1’, which has a heavy grain weight (34.8g) and is suitable for deep fried rice, by the rice breeding team at the National Institute of Crop Science, Rural Development Administration, in 2017. The heading date of ‘Hangaru’ was August 18 and was 10 days later than check variety, ‘Hwaseong’, in Suwon. It had a culm length of 79 cm and 102 spikelets per panicle, and showed similar tolerance to ‘Hwaseong’ when exposed to cold stress. ‘Hangaru’ showed medium resistance to blast disease, but susceptibility to bacterial blight, viruses and brown planthoppers. The milled rice of this variety exhibited an opaque and non-glutinous endosperm. The 1,000 grain weight of brown rice was 32.9 g, which was 10.8 g heavier than that of ‘Hwaseong’; the protein content was 7.0% and the amylose content (19.2%) was similar to that of ‘Hwaseong’. The milled rice recovery rate was lower than that of ‘Hwaseong’. However, opaque grain percentage of milled rice was 88.1%. The hardness of the rice grain was soft and the starch granule shape in the endosperm was round, similar to wheat. The average size of rice flour was 71.0 µm and the damaged starch rate was 6.4%. These results showed that this variety could be suitable for dry milling rice flour production. ‘Hangaru’ had a yield of 5.42 MT/ha of milled rice productivity in ordinary cultivation, which was 99% of that of ‘Hwaseong’. ‘Hangaru’ was adaptable to the middle plain area and Mid-west coast of Korea (Registration No. 7270).

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.

This study was executed to establish a basis of evaluation of starch properties of Korean wheat cultivars e.g. damaged starch, swelling, and pasting properties for Korean wheat breeding program. Damaged starch is critical evaluation factor for flour milling related industry because it influences water absorption and color of dough for processing quality and preference of end-use products. The present results revealed that there was significantly high positive correlation between the results of damaged starch analysis by amperometric (SD-matic) and enzymatic (Megazyme assay) methods. Evaluation of damaged starch must be considered as one factor to evaluate properties of starch due to its accuracy and a stable efficiency for the wheat breeding program. Properties of swelling and pasting of dough were important for cooking time and texture. Nevertheless, it was impossible to evaluate starch extracted from flour in the wheat breeding program i.e. small amount of flour or small number of spikes Comparison of results of evaluation of properties of swelling and pasting with starch or flour, the evaluation using flour positively correlated with the other evaluation using starch. In addition, swelling evaluation must be considered to apply for the wheat breeding program because the result of evaluation of swelling property, which possible to evaluate with low efficiency, and the quantity of a sample is highly under positive correlation with paste peak viscosity. In the future, studies using NIR (Near Infrared) analysis must be necessary to evaluate starch properties with grains in early generation lines for improvement of wheat breeding program.

Molecular markers related to flour qualities of long spike wheat lines were evaluated. Ash, wet gluten and protein content of long spike wheat lines were higher than Keumkang(Korean wheat cv.) but SDS-sedimentation volume(SDSF) was lower. Particle size and lightness of flour of long spike wheat lines showed similar to Keumkang. The high positively correlation was presented between protein content and SDSF, wet gluten and particle size, respectively. However, negatively correlation was between protein content and lightness. Through the analysis of molecular markers, we identified the genotypes of four genes, Glu-A3c, Wx-A1a, Wx-B1a and Wx-D1a. These genes had same genotypes with Keumkang. Six genes, Glu-A1c, Glu-B1c, Glu-D1a, Glu-B3g, Pina-D1and Pinb-D1b, were presented in most of the lines. Two genes, Glu-A1 and Glu-B1b, were related to higher protein contents and wet gluten. The lines containing three genotypes, Glu-D1d, Glu-B3h and Pinb-D1b, had higher ash, protein contents, SDSF and wet gluten, and lightness was darker. Through the results, we expect that long spike type wheat lines are necessary to breed wheat having high yield productivity.