찰옥수수는 풋옥수수 형태로 소비하기 위해 개발되었으나, 포엽 과 속대가 자색을 띄는 종실용 옥수수는 안토시아닌 함량이 알곡보다 높고 영양성분이 적어 기능성 유효성분을 활용하는데 효과가 높아 건강기능성식품 소재로 활용하는데 이점이
Background Genome wide association studies (GWAS) have been widely used to identify QTLs underlying quantitative traits in humans and animals, and they have also become a popular method of mapping QTLs in many crops, including maize. Advances in high-throughput genotyping technologies enable construction of high-density linkage maps using SNP markers. Objectives High-density genetic mapping must precede to find molecular markers associated with a particular trait. The objectives of this study were to (1) construct a high-density linkage map using SNP markers and (2) detect the QTLs for grain yield and quality related traits of the Mo17/KW7 RIL population. Methods In this study, two parental lines, Mo17 (normal maize inbred line) and KW7 (waxy inbred line) and 80 F-7:8 lines in the Mo17/KW7 RIL population were genotyped using the MaizeSNP50 BeadChip, an Illumina BeadChip array of 56,110 maize SNPs. Marker integration and detection of QTLs was performed using the inclusive composite interval mapping (ICIM) method within the QTL IciMapping software. Results This study was genotyped using the Illumina MaizeSNP50 BeadChip for maize Mo17/KW7 recombinant inbred line (RIL) population. The 2904 SNP markers were distributed along all 10 maize chromosomes. The total length of the linkage map was 3553.7 cm, with an average interval of 1.22 cm between SNPs. A total of 18 QTLs controlling eight traits were detected in the Mo17/KW7 RIL population. Three QTLs for plant height (PH) were detected on chromosomes 4 and 8 and showed from 16.01% (qPH8) to 19.85% (qPH4a) of phenotypic variance. Five QTLs related to ear height (EH) were identified on chromosomes 3, 4, and 6 and accounted for 3.79% (qEH6) to 27.57% (qEH4b) of phenotypic variance. Five QTLs related to water content (WC) on chromosomes 1, 4, 8, and 9 accounted for 9.55% (qWC8b) to 23.30% (qWC4) of phenotypic variance. One QTL (qAC9) relating to amylose content (AC) on chromosome 9 showed 82.10% of phenotypic variance. Conclusions The high-density linkage map and putative QTLs of the maize RIL population detected in this study can be effectively utilized in waxy and normal maize breeding programs to facilitate the selection process through marker-assisted selection (MAS) breeding programs.
In South Korea, popcorn consumption may have boomed in recent years but little has changed little for farmers or breeders. The majority of popcorn sold in the domestic market is derived from imported hybrids. The efforts are needed to identify parental lines and develop hybrids suitable for domestic conditions. However, the major constraint remains a narrow germplasm pool. Thus, knowledge of genetic variability among germplasm as well as among commercial hybrids is important to avoid genetic uniformity, thereby reducing the risk of vulnerability to stress and yield loss. Recently, the Maize Research Institute in Hongcheon developed valuable breeding material: ‘G-popcorn’, a new hybrid, together with ‘Oryun popcorn’, ‘Oryun popcorn2′, and ‘Gichan popcorn’. In this study, we assessed the genetic relationships among domestic and imported hybrids using 55 k single-nucleotide polymorphism (SNP) markers. Approximately 80% of the SNP markers were highly informative for future routine and low-cost genotyping. Considerable polymorphism among the SNP markers was observed with regard to reproducibility, ease of scoring, and minor allele frequency. Broad genetic diversity was detected among the germplasm analyzed; cluster analysis revealed the presence of two distinct groups of hybrids and generally agreed with pedigree information. In addition, we demonstrated the conversion of bead-chip SNP alleles into species-specific primers and used the ARMS-PCR technique to differentiate imported and domestic popcorn hybrids. The developed method will be useful for rapid and cost-effective identification of genetic purity among popcorn hybrids.
Zea mays L. (Poaceae), also known as purple corn, is an annual herbaceous plant that is grown as food for human consumption in a variety of forms, including cooking oils and sweeteners in processed food and beverage products. The purpose of this study was to determine whether a novel purple corn extract, FB801, might have an anti-atopic dermatitis (AD) effect on AD-like skin lesions induced by 2,4-dinitrochlorobenzene (DNCB) in BALB/c mice. Topical sensitization (1%) and challenge (0.3%) by DNCB were performed on the dorsal skin and right ear of BALB/c mice to induce AD. Following FB801 and dexamethasone administered orally, the severity of skin lesions was examined macroscopically and histologically. Serum levels of immunoglobulin E (IgE) and various cytokines were determined by enzyme-linked immunosorbent assay. Oral administration of FB801 significantly reduced typical symptoms of AD (erythema/bleeding, swelling, molting/erosion and scaling/drying), scratching frequencies, and the recruitment of inflammatory and mast cells. In addition, FB801 suppressed serum levels of IgE and T helper (Th)2 type cytokines such as interleukin (IL)-4 and IL-10 in DNCB-treated BALB/c mice. Furthermore, FB801 reduced the degradation of inhibitor of nuclear factor-κB proteins (NF-κB) in tumor necrosis factor (TNF)-α-stimulated human keratinocyte (HaCaT) cells. These results suggest that FB801 inhibited the development of the AD-like skin symptoms by regulating Th1 and Th2 responses in the skin lesions in mice and suppressing TNF-α induced NF-κB activation in HaCaT cells, suggesting that FB801 has potential application as an effective alternative therapy for the prevention and management of AD.
Background As waxy maize is considered a key economic crop in Korea, an understanding of its genetic variation and differentiation is fundamental for the selective plant breeding. The maize genome is primarily composed of transposable elements, for which large and stable insertions generate variations that reflect selection during evolution. Objectives This study was to elucidate the genetic diversity based on the contribution of TEs and to investigate the effect of Mu transposition on the genetic divergence of waxy and common maize. We also performed an association analysis on these inbred lines to determine the Mu insertions associated with agronomic traits. Methods In this study, we utilized a Mutator -based transposon display method to study the genetic diversity and population structure of 40 waxy and 40 common inbred lines of maize in the Gangwon Agricultural Research and Extension Services collection at the Maize Research Institute. Results We detected polymorphisms in 86.33% of 278 Mu tator (Mu) anchored loci, reflecting the activity of the Mu element and its contribution to genetic variation. Common maize showed a substantial amount of genetic diversity, which was greater than that observed in waxy maize. Principal-coordinate and neighbor-joining cluster analyzes consistently supported the presence of two genetically distinct groups. However, the distribution of genetic variation within the populations was much higher than the genetic differentiation among the populations. To explore the contribution of the Mu element to phenotypic variation, we analyzed the associations with ten important agronomical traits. On the basis of the combined results from two models (QGLM and Q + KLM), we found significant associations between seven Mu loci and four different traits. Conclusions These results will assist waxy maize breeders in choosing parental lines and be useful for marker-assisted selection.
In this study, we used phenotypic and genetic analysis to investigate Double haploid (DH) lines derived from normal corn parents (HF1 and 11S6169). DH technology offers an array of advantages in maize genetics and breeding as follows: first, it significantly shortens the breeding cycle by development of completely homozygous lines in two or three generations; and second, it simplifies logistics, including requiring less time, labor, and financial resources for developing new DH lines compared with the conventional RIL population development process. In our study, we constructed a maize genetic linkage map using SSR markers and a DH population derived from a cross of normal corn (HF1) and normal corn (11S6169). The DH population used in this study was developed by the following methods: we crossed normal corn (HF1) and normal corn (11S6169), which are parent lines of a normal corn cultivar, in 2014; and the next year, the F1 hybrids were crossed with a tropicalized haploid inducer line (TAIL), which is homozygous for the dominant marker gene R1-nj (Nanda and Chase in Crop Sci 6:213–215, 1966), and we harvested seeds of the haploid lines. A total of 200 SSR markers were assigned to 10 linkage groups that spanned 1145.4 cM with an average genetic distance between markers of 5.7 cM. 68 SSR markers showed Mendelian segregation ratios in the DH population at a 5% significance threshold. A total of 15 quantitative trait loci (QTLs) for plant height (PH), ear height (EH), ear height ratio (ER), leaf length (LL), ear length (EL), set ear length (SEL), set ear ratio (SER), ear width (EW), 100 kernel weight (100 KW), and cob color (CC) were found in the 121 lines in the DH population. The results of this study may help to improve the detection and characterization of agronomic traits and provide great opportunities for maize breeders and researchers using a DH population in maize breeding programs.
We report the development of new anthocyanin-rich grain corn hybrid variety ‘Saekso 2’. The seed parent, HA3 and the pollen parent, HA4 was developed from breeding materials collected from China in 2008 and from Canada in 2000, respectively. The hybrid was made in the winter of 2010/2011 and evaluated in Hongcheon for 3 years. After evaluation, the selected variety was named ‘Saekso 2’ and was approved for a variety registration in 2017. Anthocyanin content of Saekso 2 in grain was 685 mg/100g and was much higher than that of Saeko 1(0mg/100g). Since regional tests was conducted in only Gangwon province, it is recommended only in that region for commercial cultivation. For the highest content of anthocyanin, it is best to harvest grains at around 45 days after silking. Saekso 2 is the first hybrid bred specifically for processing for high anthocyanin production.
In this study, a total of 80 F-7:8 recombinant inbred lines (RIL), derived from a cross between dent corn inbred line, Mo17 and waxy inbred line KW7, were evaluated for 11 flowering and yield-related traits. Correlation analysis was performed among the 11 flowering and yield-related traits. DA showed the highest correlation with DS (0.747**). DS via ASI (0.619**), TC via SC (0.595**), CB via ER (0.535**) showed relatively high correlation coefficients than the other trait combinations. Quantitative trait loci (QTL) and epistatic interactions were detected for 11 flowering and yield-related traits. Our study detected a total of 32 QTLs and 40 epistatic interactions for 11 flowering and yield-related traits. The 15 QTLs were major QTLs which had more than 15% phenotypic variation (16.29 similar to 82.45%). qKT9 had the highest phenotypic variance (82.45%) in marker interval between umc1634 and wx1. The qDS1a and qASI1a were co-located within a region flanked by two adjacent SSR markers on chromosome 1 (umc1354 and bnlg1179) and qDS1b and qASI1b were co-located within a region flanked by two adjacent SSR markers on chromosome 1 (umc1166 and umc1976). In addition, two QTLs, qCB3 and qDA3 shared umc1949 and Two QTL, q10V5 and qDS5 also shared umc2373. Another QTL, qER10 and qASI10 shared umc1645. This tight link supported high correlation of each trait. Finally, these SSR marker pairs are useful selection tools for screening flowering and yield related traits. To perform MAS efficiently, it is important to identify genes or traits on the chromosomal segment linked to the target gene. Thus, the detection and confirmation of loci associated with main agronomic traits presented may provide greater opportunities for maize breeders to improve quality with marker associated selection.
Soil moisture shortage can reduce yield of waxy corn because maize is one of the sensitive crops to the drought stress. Farmers cannot irrigate due to limited water resource and irrigating facilities although applying water is the most effective practice to solve the drought problem. The study was conducted to investigate the pre-treatment effect of salicylic acid on reducing drought damage of waxy corn (Zea mays L.). Salicylic acid at concentration of 0.2 mM was applied at seven-leaf stage or ten-leaf stage three times. Drought stress was imposed by withholding irrigation from 11 days before anthesis to 10 days after anthesis. Application of salicylic acid significantly increased ear length by 11.0~12.3% and yield by 8.8~11.3% compared with non-treated control, indicating that the drought injuries of waxy corn can be alleviated through pre-treatment of salicylic acid at the vegetative stage.
Assessing genetic diversity, population structure, and linkage disequilibrium is important in identifying potential parental lines for breeding programs. In this study, we assessed the genetic and phenotypic variation of 174 normal maize (Zea mays) inbred lines and made association analyses with respect to nine agronomical traits, using 150 simple sequence repeats (SSR). From population structure analysis, the lines were divided into three groups. Association analysis was done with a mixed linear model and a general linear model. Twenty-one marker-trait associations involving 19 SSR markers were observed using the mixed model, with a significance level of P < 0.01. All of these associations, as well as 120 additional marker-trait associations involving 77 SSR markers, were observed with the general model. Two significant marker-trait associations (SMTAs) were detected at P ≤ 0.0001. In the mixed linear model, one locus was associated with water content, two loci were associated with 100-kernel weight, setted ear length, ear thickness and stem thickness; three loci were associated with ear height, four loci were associated with total kernel weight and five loci were associated with plant height. These results should prove useful to breeders in the selection of parental lines and markers.
In this study, genetic diversity, genetic relationship, population structure and association analysis among 12 colored and non-colored maize lines were investigated using 300 simple sequence repeat (SSR) markers. In genetic diversity analysis, a total of 1,331 alleles were identified at all the loci with an average of 4.44 and a range between 2 and 10 alleles per locus. The major allele frequency varied from 0.25 to 0.92 with an average of 0.48. Among 1,331 alleles, 221 alleles were colored maize specific allele, and 408 alleles were non-colored maize specific allele. While 702 alleles were shared in colored and non-colored maize lines. In addition, colored maize specific alleles were detected in 163 SSR markers. From population structure analysis, the 12 colored and non-colored maize lines were separated with based on the membership probability threshold 0.8, and divided into groups I, II, III and admixed group. The results of this study could serve as useful molecular markers for identification and characterization of colored and non-colored maize lines in the maize breeding studies.
Dapyeongok', a new maize F1 hybrid (Zea mays L.), is developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2010.The high-yielding hybrid, named 'Dapyeongok' was bred by crossing between two inbred lines, 'KS158' and 'KS155'.It is a yellow dent maize hybrid (Zea mays L.).After preliminary yield trial and advanced yield trial of Dapyeongok in Suwon for two years, regional yield trial of that was subsequently carried out for evaluation of its growth and yield at three different locations from 2008 to 2010.The silking date of Dapyeongok is the same with that of the check hybrid, 'Jangdaok'.The plant height of Dapyeongok is similar to Jangdaok, and its ear height ratio is the same with that of Jangdaok.It has resistance to lodging.The ear length of Dapyeongok is shorter than that of Jangdaok.The weight of 100 seeds of Dapyeongok is lighter than that of Jangdaok.It has strong resistance to northern leaf blight (Exserohilum turcicum) and southern leaf blight (Bipolaris maydis).It has moderate resistance to black streaked dwarf virus (BSDV), ear lot and corn borer.The grain yield (8.6 ton/ha) of Dapyeongok was 8% higher than that of Jangdaok.The seed production of Dapyeongok has gone well due to a good synchronization of flowering period during crossing between the seed parent, KS158, and the pollen parent, KS155, in Yeongwol and F1 seed yield was 2.8 ton/ha.Dapyeongok would be a suitable cultivar to all plain area in Korea.