Barley is an economically important cereal crop grown under diverse environmental conditions and ranked fourth in terms of production volume. Barley is a diploid self-fertilizing plant with seven chromosomes, and has a 5.1 Gbp genome with more than 80% repeat sequences. Whole genome re-sequencing (WGR) has provided substantial information on sequence variation distributed on all chromosomes, such as single nucleotide polymorphisms, insertions, and deletions, which are used in the development of DNA markers. In this study, we performed WGR to detect sequence variations among six Korean malting varieties. An average of 92,552 insertions and deletions (InDels) were detected in these varieties in comparison to the high-quality reference genome sequences. The InDel density of the six Korean malting varieties ranged from 17 to 19 InDel/1Mbp with an average of 18 InDel/1Mbp. No InDel could be detected in 193 regions in all chromosomes except chr. unassigned. One interval with high-density InDel, more than 150 InDel/1Mbp, was located on the 1H, 3H, 6H, and 7H chromosomes. A total of 145 InDel markers were developed using 225 large-InDel markers, longer than 50 bp. Seventeen large-InDel makers showed polymorphisms among 31 malting barley varieties. These 31 malting barley varieties were divided into four groups based on phylogenetic analysis. These results presented a development method of agarose-resolvable large-InDel markers using WGR. Seventeen polymorphic large-InDel markers were used to conserve and identify barley germplasms. This vast information on sequence variation in six Korean malting barleys could be used for the development of DNA markers and marker-assisted selection.

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).

Association analysis was conducted to identify quantitative trait locus (QTL) of yield potential traits, days to heading date, culm length, spike length and kernels per spike in the genetic mapping population (94 F₁₀ recombinant inbred line) produced from a cross between two Korean wheat cultivars, Taejoong which has a large kernel number line, a longer spike length, and a higher kernel number per spike and Keumkang. Yield potential traits, days to heading date, culm length, spike length and kernels per spike were evaluated in 2017 and 2018 under upland conditions. Days to heading date were biased toward late heading date (skewness=-0.3), and spike length was biased toward short spike length (skewness=0.7). A genetic map was constructed with 57 microsatellite marker loci and two QTLs were detected for spike length. The first QTL on chromosome 2A, qSL-1 was detected by Xcfd5 and Xpsp3050 and explained 20.7% of phenotypic variation. The second QTL on chromosome 5B, qSL-2 was detected by Xwmc656 and Xwmc415 and explained 40.8% of phenotypic variation. These QTLs were applied to validate the relationships between genotypes of QTLs and 29 Korean wheat cultivars cultivated for nine years, from 2010 to 2018. The Korean wheat cultivars were classified into 6 types according to the genotypes of Xcfd5-Xpsp3050 and Xwmc656-Xwmc415. The same genotypes as Keumkang showed a higher frequency and shorter spike length than that of Taejoong in Korean wheat cultivars.

Salt stress is a significant factor limiting growth and productivity in crops. However, little is known about the response and resistance mechanism to salt stress in maize. The
objective
of this research was to develop an enhanced salt-tolerant silage maize by mutagenesis with gamma radiation. To generate gamma radiation-induced salt-tolerant silage maize, we irradiated a KS140 inbred line with 100 Gy gamma rays. Salt tolerance was determined by evaluating plant growth, morphological changes, and gene expression under NaCl stress. We screened 10 salt-tolerant maize inbred lines from 2,248 M₂ mutant populations and selected a line showing better growth under salt stress conditions. The selected 140RS516 mutant exhibited improved seed germination and plant growth when compared with the wild-type under salt stress conditions. Enhanced salt tolerance of the 140RS516 mutant was attributed to higher stomatal conductance and proline content. Using whole-genome re-sequencing analysis, a total of 328 single nucleotide polymorphisms and insertions or deletions were identified in the 140RS516 mutant. We found that the expression of the genes involved in salt stress tolerance, ABP9, CIPK21, and CIPK31, was increased by salt stress in the 140RS516 mutant. Our results suggest that the 140RS516 mutant induced by gamma rays could be a good material for developing cultivars with salt tolerance in maize.

Rice breeders or sensory evaluators are striving to develop the rapid and correct sensory evaluation method of the cooked rice with a small-sample. This study was conducted to develop a method of cooking condition and sensory evaluation of the cooked rice rapidly and correctly with a small-sample by introducing a concept of arrangement ranking to the conventional sensory evaluation method by cooking in the cup, which has been used only as a simple test. A method of simultaneous cooking of the five samples for one round of test was developed. And, an arrangement ranking method was developed just like stacking a tower by arranging the cups in the sensory evaluation. The proposed method was named as cup arrangement ranking method. The correlation analysis between the cup arrangement ranking method (CARM) and the standard sensory evaluation method (SSEM) showed a high significance of correlation (r=0.83^**~0.91^**, ‘13~’14). Further, when effectiveness of proposed method was compared with the standard sensory evaluation method, the sample quantity was a 30g level for one round of test, which is a tenth of SSEM. The time consumed for sensory evaluation was two minutes per one sample, which was a reduced value by half as compared with the time consumption by SSEM. Therefore, the cup arrangement ranking is expected to be an effective method in the selection of excellent rice line or variety having good taste by evaluating the cooking quality rapidly with a small-sample in early generation.