A comprehensive evaluation of 515 Korean wheat germplasms, including cultivars, experimental lines, and landraces, was conducted over 2 years under upland field conditions to characterize major agronomic and grain traits. Allelic variation at 13 key functional loci was assessed using Kompetitive Allele-Specific PCR (KASP) and PCR-based markers. The winter-type vrn-A1 with a single copy (CNV=1; 40.2%) advanced heading by approximately 5 days compared to multiple-copy genotypes, and winter-type vrn-B1 (88.5%) advanced heading by 2 days compared to the spring-type. The photoperiod-insensitive alleles Ppd-B1a (5.6%) and Ppd-D1a (76.3%) advanced heading by 3 and 4 days, respectively, with a combined effect of up to 6 days. Semi-dwarfing alleles Rht-B1b and Rht-D1b showed reduced culm lengths of 2.1 cm and 4.7 cm, respectively, and the Rht-B1a/Rht-D1b genotype was 6 cm shorter than Rht-B1a/Rht-D1a. The Pina-D1a/Pinb-D1a genotype had the lowest kernel hardness value (32.2), whereas Pina-D1b/Pinb-D1a had the highest (60.5). The thousand kernel weight ranged from 36.1 mg to 42.5 mg depending on the allelic combinations of TaCwi-A1, TaGW2-6A, and TaSus2-2B. Cultivars and experimental lines were clearly distinguished from landraces based on phenotype-based clustering, with the majority of cultivars (81.6%) and experimental lines (68.3%) grouped into cluster III. In contrast, landraces were predominantly distributed in clusters I (55.1%) and II (29.2%). Random forest analysis identified four genes, Ppd-D1, Pina-D1, Pinb-D1, and WAPO-A1, as major contributors to cluster classification. Cluster III was highly enriched with alleles favorable for earliness (Ppd-D1a, 98.3%) and grain hardness (Pina-D1b and Pinb-D1b, 57.9%). WAPO-A1b, an allele associated with an increased spikelet number per spike, was more frequently observed in clusters I (94.6%) and II (79.1%) than in cluster III (58.4%).

A new covered barley cultivar ‘Hangang’ with resistance to barley yellow mosaic virus (BaYMV) and tolerance to cold was developed by crossing ‘Samkwangchal/Radiant’ at the National Institute of Crop Science, RDA in 2018. The regional yield trials were conducted for ‘Hangang’ as a breeding line ‘Jeonju498’ in five different regions from 2016 to 2018. The average heading date of ‘Hangang’ was April 22, which was one day earlier than that of ‘Olbori’. The maturing date of ‘Hangang’ was May 30, which was similar to that of ‘Olbori’. The culm length was 81 cm, which was shorter than that of ‘Olbori’, showing tolerance to lodging stress. ‘Hangang’ showed the spike length of 4.6 cm with 669 spikes per m², 54 grains per spike, and a weight of 33.5 g for 1,000 grains. Compared with ‘Olbori’, ‘Hangang’ showed stronger withering in winter (winter hardiness) and resistance to BaYMV. Among quality characteristics, ‘Hangang’ showed similar levels as those of ‘Olbori’ with respect to protein, β-glucan and amylose (10.7%, 4.6%, and 18.8%, respectively). However, ‘Hangang’ showed higher polyphenol content (1.69 mg/g) than the check cultivar. The yield of ‘Hangang’ in the regional yield trial was 611 kg/10a in upland, 502 kg/10a in paddy field, and an overall average of 567 kg/10a, which was 15%, 16% and 16% higher than that of the check cultivar, respectively. Therefore, ‘Hangang’ will be suitable cultivar when sowed in cold regions (Registration No. 8773).

This study was conducted to investigate the effect of starch properties on the texture of cooked noodles from Korean wheat. The genetic composition of GBSS I (granule bound starch synthase I, called waxy protein) and puroindoline, which affect the amylose content and kernel hardness, was also evaluated. Waxy wheats carrying Wx-1 null alleles showed clearly different starch properties, high swelling power, pasting viscosity, breakdown and paste clarity, unsuitable texture of cooked noodles, and low hardness and springiness. Two partial waxy soft wheats carrying single or double null alleles at the Wx-1 locus gene, and Pina-D1a and Pinb-D1a alleles exhibited a softer and higher elasticity texture of the cooked noodles than Korean wheats carrying wild-type Wx-1 null alleles. There were no significant differences in the starch properties and texture of cooked noodles according to the puroindoline composition. A principal component analysis showed a strong negative relationship between the amylose content and starch swelling power, and these traits also improved the springiness and cohesiveness of the cooked noodles prepared from non-waxy Korean wheat. Joongmo2012, a double null partial waxy wheat, showed higher starch swelling power and springiness of the cooked noodles than other non-waxy Korean wheats.

A new winter wheat (Triticum aestivum L.) cultivar ‘Baekkang’ was developed by the National Institute of Crop Science (NICS) and Rular Development Administration (RDA) in 2015. Its heading date was April 23, and its maturity date was June 3, similar to that of ‘Keumkang’. ‘Baekkang’ had a shorter culm length (75 cm), longer spike length (8.0 cm), more spikes per m² (703), and more 1,000-grain weight (47.5 g) than those of ‘Keumkang’, which were 76 cm, 7.6 cm, 631, 46.4 g, respectively. ‘Baekkang’ was not a winter hardy crop and is susceptible to powdery mildew. However, it has moderate resistance to fusarium head blight. The average grain yield in the advanced yield trial was 5.5 MT/ha, 20% more than ‘Keumkang’. In the regional yield trial, this average yield was 5.1 MT/ha upland and 5.2 MT/ha in the paddy field, which were 10% and 18% more than that of ‘Keumkang’, respectively. Baekkang’s flour yield (71.2%) and flour lightness (92.40) showed similarities to those of ‘Jokyung’. ‘Baekkang’ also showed a higher protein content (12.4%), gluten content (10.1%), and SDS-sedimentation volume (60.0 ml). These results showed that the ‘Baekkang’ flour’s dough strength was greater than that of ‘Jokyung’. Baekkang’s high molecular weight gluten subunits composition was Glu-D1 (5+10), granule-bound starch synthase composition was Wx-A1 (a), Wx-B1 (a), and Wx-D1 (a), and puroindoline composition was Pina-D1(a) and Pinb-D1(b) (Registration No. 6966).

AbstractStem rust is a major wheat disease caused by the fungus Puccinia graminis f. sp. tritici (Pgt). Occurring mainly in warm and humid climates, stem rust has generally been considered less prevalent than leaf rust (P. triticina) and stripe rust (P. striiformis f. sp. tritici). However, a highly virulent stem rust race, Ug99, appeared in Uganda in 1998 and has devastated wheat production throughout Africa and the Middle East. As damage caused by the Ug99 lineage and other newly diverging stem rust races continues to increase, extensive research on wheat breeding and genetics to enhance stem rust resistance has been conducted internationally. Among the 60 stem rust resistance genes reported thus far, 11 (Sr13, Sr21, Sr22, Sr33, Sr35, Sr45, Sr46, Sr50, Sr55, Sr57, and Sr60) have been cloned. New resistance sources have been sought by screening diverse wheat germplasms through international collaborations. Such efforts are urgently required in Korea to address the increasing threat of stem rust epidemics. Furthermore, major Pgt races in the Korean peninsula need to be pathotyped. This information can be used to screen major wheat cultivars, breeding lines, and landraces to identify effective resistance sources. Previously reported stem rust resistance genes should also be introduced and pyramided into the genetic background of Korean wheat breeding populations via available molecular markers. Finally, research capacity in molecular genetics and genomics needs to be strengthened to enable the identification of new stem rust resistance genes and the development of precise molecular markers.

AbstractExtensive research has been conducted in wheat to improve genetic resistance to rust, a major disease that deteriorates wheat yield and quality worldwide. Leaf rust caused by Puccinia triticina is the most prevalent among the three major wheat rust diseases (leaf, stripe, and stem rust) globally and is adapted to a wide range of climates. Approximately 80 genes for leaf rust resistance have been reported, and six (Lr1, Lr10, Lr21, Lr22a, Lr34, and Lr67) have been cloned. Among these cloned genes, Lr34/Yr18/Sr57/Pm38 and Lr67/Yr46/Sr55/Pm46 are of special interest for breeding programs, as they provide pleiotropic resistance to stripe rust, stem rust, and powdery mildew as well as leaf rust. In Korea, knowledge on wheat breeding and genetics for rust resistance is insufficient, as agronomic measures have mainly been used to avoid rust. Therefore, an extensive research program to address the increasing threat of rust epidemics due to climate change is urgently required. Major Korean wheat cultivars, breeding lines, and landraces should be screened for leaf rust resistance. Diverse germplasms also need be introduced through international collaborations to broaden the genetic background for resistance. It is equally important to characterize the distribution of different leaf rust races in Korea and respond to changes in pathogen populations by using effective resistance genes in breeding programs. Research on molecular genetics and genomics needs to be furthered to identify new leaf rust resistance genes and develop efficient molecular markers.

Stripe rust (or yellow rust) caused by Puccinia striiformis f. sp. tritici is the major wheat disease responsible for deteriorating global wheat yield and quality. Although stripe rust appears to be prevalent mainly in temperate areas, new races adapting to high temperature have recently appeared in warmer areas, such as Australia, the Middle East, and Africa, increasing the threat to global food security. Among the approximately 80 reported genes for stripe rust resistance, six (Yr5, Yr7, Yr15, Yr18, Yr36, Yr46) have been cloned. Stripe rust resistance genes are generally classified into race-specific (or all-stage) and non-race-specific (or high temperature adult plant) resistance genes. While resistance conferred by most race-specific genes are overcome by the appearance of new pathogen races within few years, non-race-specific genes, such as Yr18, Yr36, and Yr46, provide more durable resistance and are often stable for several decades. Yr18/Lr34/Sr57/Pm38 and Yr46/Lr67/Sr55/Pm46 are especially useful in breeding as they confer resistance to leaf rust, stem rust, and powdery mildew as well as stripe rust. Unlike the extensive global research efforts, few studies have been conducted in Korea regarding breeding and genetics for stripe rust resistance. To prevent damage by stripe rust in advance, it is important to monitor the changes in major pathogen races in Korea, evaluate major wheat breeding lines and landraces for stripe rust resistance by establishing an efficient screening system, and introduce new germplasm with various resistance genes. Reinforcing wheat molecular genetics and genomics capacity is also important to enable identification of new stripe rust resistance genes and efficient transfer of the novel genes into elite wheat cultivars using molecular markers.

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).

Barley and wheat are a major food crop of humans, along with rice, soybean and corn. A systematic breeding program for Korean barley began in 1906 with selection and introduction breeding. In 1908, landrace barley was collected, and breeding focused on selection and introduction for high yielding varieties until the 1970s. In the 1980s and 1990s, breeding was carried out for diversity; thereafter, we aimed to improve quality, productivity and lodging tolerance that can be applied to the paddy field in Korea. Since 2010, the major result of breeding was shortening cultivation to approximately 6–12 days, making a double cropping system possible in the paddy field in Korea. Yield has increased by 1.2 times from 438 kg/10 a in the 1960s to 536 kg/10 a in the 2010s, and farm yield has increased by 1.7 times. In addition, as cultivation safety has been enhanced, the varieties have also improved, such as the covered barley used in making tea and other processing products. In case of wheat, up to now forty cultivars have been developed in Korea. In the early stage, we developed a domestic wheat variety that was early maturing and high yielding. As a result, the maturation time of wheat planted in the 1970s to 2010 was shortened (from 13 to 30 days), while productivity increased by 30% from 408 kg/10 a in the 1970s to 532 kg/10 a in 2010. In recent years, there have been remarkable efforts for a more stable production by focusing on increasing disaster and pest resistance due to climate change. In addition, a wheat variety discrimination marker was developed using a variety-specific marker, and selection was made using a trait-specific marker at the early stage of breeding to enhance breeding efficiency. In the 2000s, winter cereals for forage have been promoted to expand forage production and to replace imported feed grains. Therefore, winter cereal that is useful for feed, such as rye, oat, and triticale, have had various varieties and safe production techniques developed. Currently, our research goal for winter cereals for feed is to develop a double-cropping adaptation and abiotic stress tolerance cultivar, and safe production in paddy field. Hence, aggressive action is needed to support the strategic survival of the Korean wheat and barley industry. Barley is a health food that requires a multifaceted effort to improve breeding efficiency, develop varieties that contain large amounts of functional components and are more resistant to stronger biotic and abiotic stresses in response to climate change. It is necessary to recognize the role of wheat and barley as the second main crop after rice, and to improve the self-sufficiency rate of these crops for the health and food industry crisis of Korea.

A winter wheat (Triticum aestivum L.) cultivar, ‘Taejoong’, was developed by the National Institute of Crop Science, Rural Development Administration in 2016. It was derived from a cross between ‘Xian83(104).11’ and ‘Keumkang’ in 2005. It was generated through the bulk and pedigree methods for six years, and then designated as ‘Iksan370’ after a two-year advanced yield trial test. This variety was designated the name ‘Taejoong’ after a regional yield trial test in eight locations throughout Korea for three years from 2014 to 2016. Its heading date was April 27 in upland and paddy filed conditions, and its maturity date was June 7 in uplands and June 4 in paddy fields, which were late compared to that of ‘Keumkang’. ‘Taejoong’ had 417 spikes per m², which was 300 less than that of ‘Keumkang’. However, the spike length was 13.4 cm and the number of kernel per one spike was 48, which was 5.8 cm longer and 19 higher than those of ‘Keumkang’, respectively. ‘Taejoong’ showed strong resistance to lodging and moderate resistance to Fusarium head blight, but was susceptible to powdery mildew. ‘Taejoong’ flour yield (71.8%) and flour lightness (91.90) were similar to those of ‘Keumkang’, but its protein content (11.1%), gluten content (8.8%), and sodium dodecyl sulfate-sedimentation volume (34.2 ml) were lower. These result showed that the flour dough strength of ‘Taejoong’ was weaker than that of ‘Keumkang’. The high-molecular-weight gluten subunit compositions of ‘Taejoong’ were Glu-A1 (N), Glu-B1 (7+9), and Glu-D1 (2+12). The granule-bound starch synthase compositions were Wx-A1, Wx-B1, and Wx-D1. The puroindoline compositions were Pina-D1 (a type) and Pinb-D1 (b type). The average grain yield of ‘Taejoong’ in a regional yield trial was 5.3 ton/ha in uplands and 4.6 ton/ha in paddy fields, which were 21% and 13% higher than that of the reference cultivar, ‘Keumkang’, respectively. (Registration No. 7378).

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.

A new black barley variety, “Heuksoojeongchal,” was developed as a cross between “Keunalbori 1” and “Masankwamaek/Mortoni” at the National Institute of Crop Science, RDA in 2014. Heuksoojeongchal had a longer culm length (89 cm) and a later average heading date and maturity than Seodunchalbori. It also had a spike length of 5.0 cm, 543 spikes/m², and 54 grains/spike. The 1000-grain weight of Heuksoojeongchal (36.0 g) was heavier than that of Seodunchalbori. Heuksoojeongchal showed resistance to barley yellow mosaic virus (BaYMV). The yield potential of Heuksoojeongchal was approximately 7% higher than that of Seodunchalbori upland, but the average yield potential was similar in upland and paddy fields. Among the quality characteristics, the β-glucan content (6.7%) was higher and the amylose content (5.5%) was lower than those of Seodunchalbori. The whiteness of the black barley was low, and its absorption rate and spreadability were similar to those of Seodunchalbori.