• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.430-441
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• 2011

Maize is divided into two types based on the starch composition of the endosperm in the seed, normal maize(or non-waxy maize) and waxy maize. In this study, genetic diversity and population structure were investigated among 80 waxy maize and normal inbred lines(40 waxy maize inbred lines and 40 normal maize inbred lines) using 50 SSR markers. A total of 242 alleles were identified at all the loci with an average of 4.84 and a range between 2 and 9 alleles per locus. The gene diversity values varied from 0.420 to 0.854 with an average of 0.654. The PIC values varied from 0.332 to 0.838 with an average of 0.602. To evaluate the population structure, STRUCTURE 2.2 program was employed to confirm genetic structure. The 80 waxy and normal maize inbred lines were separated with based on the membership probability threshold 0.8, and divided into groups I, II and admixed group. The 13 waxy maize inbred lines were assigned to group I. The 45 maize inbred lines including 7 waxy maize inbred lines and 38 normal maize inbred lines were assigned to group II. The 22 maize inbred lines with 20 waxy maize inbred lines and 2 normal maize inbred lines were contained in the admixed group. The cluster tree generated using the described SSR markers recognized three major groups at 31.7% genetic similarity. Group I included 40 waxy maize inbred lines and 11 normal maize inbred lines, and Group II included 27 normal maize inbred lines. Group III consist of only 2 normal maize inbred lines. The present study has demonstrated the utility of SSR analysis for the study of genetic diversity and the population structure among waxy and normal maize inbred lines. The information obtained from the present studies would be very useful for designing efficient maize breeding programs in Maize Experiment Station, Kangwon Agricultural Research and Extension Services.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.179-184
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• 2003

The use of high amylose maize varieties significantly affected the alkaline-cooking process and characteristics of alkaline-processed food products, such as masa and tortilla chips. High amylose maize varieties had softer endosperm textures with move tightly attached pericarps than normal maize. Masa prepared from high amylose mutant maize was less cohesive than that of normal maize due to insufficient dispersion of amylopectin and excessive retrogradation of starches. Tortilla chips prepared from amylose-extender dull (ae du), amylomaize V, and Ⅶ had slightly increased oil absorption, while tortilla chips from dull (du) and amylose-extender sugary-2 (ae su-2) had oil contents similar to that of control chips. Increased oil absorption of the tortilla chips was due to their increased surface area. Tortilla chips produced from high amylose mutant maize had darker color than control chips, presumably due to the pigmented pericarp tissues, higher levels of reducing sugars, and phenolic compounds present in the kernel.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.484-491
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• 2023

Maize is one of the major crops consumed in worldwide, which nutrients accounts for a large amount of starch, but also functional components, and phenolic acid is known to have a high content. Maize is divided into waxy maize, sweet maize, and normal maize with its shape and use, therefore there is also a difference in nutritional composition. This study was conducted to analyze the content of functional components according to the type of maize and to produce natural variation data in consideration of environmental factors. 3 shapes of maize (waxy maize, sweet maize, and normal maize) samples cultivated in 3 regions (Suwon, Daegu, and Hongcheon) were analyzed using HPLC and GC-TOF-MS. Comparing with type through ANOVA, multivariate statistical analysis, Pearson correlation analysis, 28 components, including carotenoids and tocopherols, showed significant differences among a total of 32 components (p <0.05), 15 of them showed very significant differences (p <0.001). When comparing with regions, 15 components showed significant differences and only vanillate, syringate, C23-ol of them showed most significant differences (p <0.001). As a result of principal component analysis, cluster classification was distinguished by shape than by region, with α-carotene, cholesterol for waxy maize, vanillate and stigmasterol for sweet maize, lutein and β-carotene for normal maize had a great effect on cluster formation. It suggests that the content of functional components is more affected by genetic factors than environmental factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.16-23
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• 1987

This experiment was conducted to determine the isozymic differences between normal maize and maize inbreds of multiple ears and tillers (MET). Two maize inbreds Euisung, Iri and their hybrid having tillers and multiple ears were compared with normal maize. With usual electrophoresis using 6% polyacrylamide gel, peroxidase and esterase enzymes were studied. Matured leaf, culm, leaf sheath, root and young ear tissues showed different isozymic patterns between METs and normal maize in peroxidase. The Euisung inbred grown for 7 days under dark condition showed typical peroxidase. bands compared with checks in the tissues of coleoptile and stele. Better observation of isozymic bands was made during early part of maize growth. Parental inbreds showed more active and apparent band differences than their hybrids in esterase. Bands for esterase were also apparently different in the stele, coleoptile and young ear tissues of the METs and the checks. The maize lines infected with black streaked dwarf virus showed obvious differences in peroxidase and esterase isozymes.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1626-1631
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• 2010

An experiment was conducted to evaluate the effect of dietary replacement of normal maize (NM) with quality protein maize (QPM) on performance, immune response and carcass characteristics of broiler (Krishibro) chickens. Six experimental diets were prepared separately for starter and finisher phases. Diet 1 was a control diet formulated with NM and soybean meal. In diets 2-5, the NM was replaced with QPM at 25, 50, 75 and 100%, respectively. Diet 6 was the same as the control diet, but supplemented with synthetic lysine similar to the industry standard. Each test diet was fed to 8 replicates, each of 5 chicks, reared in stainless steel battery brooders. The AME content of QPM (3382 kcal/kg) was similar to that of NM (3,352 kcal/kg), but protein (9.91 vs. 8.94%), lysine (0.40 vs. 0.26%) and tryptophan (0.09 vs. 0.07%) contents of QPM were higher than NM. Dietary replacement of NM with 50% QPM significantly (p<0.05) improved body weight gain, feed conversion ratio, humoral immune response, relative bursa weight, and breast muscle yield and lowered abdominal fat content. No further improvement in these parameters was recorded by increasing the level of replacement of NM with QPM to either 75% or 100%. Further, the improvement noticed in the 50% QPM group was similar to the group fed the NM diet with lysine supplementation, and thus dietary replacement of NM with QPM at 50% did not need extra synthetic lysine supplementation. It is concluded that dietary replacement of NM with QPM at the 50% level resulted in optimum performance, higher breast muscle yield and higher immune response in broiler chickens.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.312-318
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• 2014

We evaluated the morphological characteristics of 156 maize inbred lines, which were developed to breeding normal maize variety at Maize Experiment Station, Gangwon Agricultural Research and Extension Services, by examining 11 quantitative and three qualitative characteristics. On the evaluation of three qualitative traits for 156 maize inbred lines, most inbred lines showed yellow (85 and 84 inbred lines) at tassel color (QL1) and silk color (QL2), and showed semi erect (105 inbred lines) at plant type (QL3). While, the evaluation of 11 quantitative traits for 156 maize inbred lines, they showed the morphological variation in days of tasseling (QN1, 56.5 to 76.0 days), days of silking (QN2, 59.0 to 85.5 days), stem thickness (QN3, 12.7 to 42.9 mm), plant height (QN4, 111.8 to 239.8 cm), ear height (QN5, 48.2 to 126.5 cm), 100 kernel weight (QN6, 14.9 to 36.4 g), ear length (QN7, 10.0 to 79.0 cm), setted kernel length (QN8, 8.0 to 70.5 cm), ear thickness (QN9, 4.0 to 22.0 cm), total kernel weight (QN10, 22.0 to 490.0 kg) and water content (QN11, 9.3 to 11.9%), respectively. As a result, 11 inbred lines (00hf3, 00hf19, 00hf30, 00hf36, 02S8069, 02S8072, 02S8090, 02S8099, 05S10011, 06S8085-6, 07S8011) in the 156 normal maize inbred lines have showed comparatively high values. While, the results of PCA (principal component analysis) indicated that the ear length (QN7), setted kernel length (QN8), ear thickness (QN9) and total kernel weight (QN10) greatly contributed in positive direction on the first principal components. And also, days of tasseling (QN1), days of silking (QN2), plant height (QN4) and ear height (QN5) contributed in negative direction on the second principal component. Thus these morphological characters, which were greatly contributed in the first and second principal components, might be considered to be useful for discrimination among 156 normal inbred lines. Specifically, this study's assessment of morphological characteristics of 156 normal inbred lines will be helpful useful for normal maize breeding programs such activities as planning crosses for hybrid and line development at Maize Experiment Station, Gangwon Agricultural Research and Extension Services.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1309-1315
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• 1997

Yields of enzyme-resistant starch (RS) from three kinds of maize starches (Amioca, normal starch and Amylomaize VII) which were treated with 1 N HCl for 24 hr and physicochemical characteristics were investigated. Hydrolysis rate of maize starches decreased with increasing amylose content. Maximum wavelength $({\lambda}_{max})$ and iodine affinity were decreased by the acid treatment. The yields of RS increased with acid treatment up to 12 hr and then decreased. The yield of for 12 hr acid-treated Amioca increased 8 times more than untreated sample, but those of normal starch and Amylomaize VII slightly increased. Using SEM, acid-treated and autoclaved maize starches showed gel like structure, but RS had round and rod shape small particles. X-ray diffraction patterns of autoclaved starches showed amorphous structure in Amioca and B-type in normal starch and Amylomaize VII, and those of RS showed all completely crystalline structure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.57-64
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• 1969

Several field and sweet corn varietiea from several sources were crossed with a variety carrying the opaque-2 gene to determine the phenotypic interactions in the breeding of high lysine maize. Although opaque-2 lines showed lower protein content than the corresponding normal varieties, there was no correlation between the protein levels of the two types. opaque-2 maize contained more lysine, but no relationship was found between the protein content and the lysine content of either normal or opaque-2 types, suggesting that high lysine corn using the opaque-2 gene may be developed independently from the protein content. The F2 segregation ratios for normal and opaque-2, 100-kernel weights, percentage seed set, opaque-2 phenotype, disease susceptibility, and the relationship between protein and lysine content of normal and opaque-2 were investigated. The determinations and observations were made on the F2, F3, and BC1 Lysine content was determined by the ion exchangeresin combined with paper chromatography method. Most crosses segregated in a 1-opaque-2 : 3-normal ratio as expected. Opaque-2 segregates were lighter than the normal type and smaller in size. A mottled phenotype of opaque-2 maize observed in the Philippines yellow endersperm. In some varieties opaque-2 maize was very susceptible to the ear and kernel rot disease. No. 5(female) and opaque-2(male). Selectlon of a double mutant of waxy and opaque-2 by using the iodine technique and electric lamp was discussed. opaque-2 and floruy-2 were not allels. Different percentage of seed set were observed in the segregation of aewx crossed with opaque-2. An unusual gametophytie relationship was involved in a cross between Glutinous.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.116-122
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• 2002

Dehydrins (LEA Dll proteins) are one of the typical families of plant proteins that accumulate in response to dehydration, cold stress, abscisic acid, or during seed maturation. A 1.3-kb cDNA was cloned from a cDNA expression library of 5-day-old germinating maize scutellums under drought stress. The deduced protein sequence indicated a dehydrin gene encoding SK$_3$ LEA protein typically expressed during cold acclimation, but not by drought stress in barley and wheat. Thus, it was named maize DEHYDRIN2 (ZmDhn2). It accumulates rapidly and highly in drought-stressed scutellum and leaf tissues at any stage, but not under cold stress. ZmDhn2 gene was transformed into Arabidopsis thaliana for functional analysis under drought condition. From electrolyte leakage test, no significant difference showed between wild type and transformants under normal growth condition, but the leakage level of electrolyte in wild type plants was about 3 times as high as that in the transformed plants under drought stress. It suggests that ZmDHN2 playa role in increasing drought tolerance.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1207-1213
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• 2020

Aflatoxin B1 (AFB1) is a mycotoxin produced by Aspergillus flavus (A. flavus). AFB1 is reported to have high thermal stability and is not decomposed by heat treatment during food processing. Therefore, in this study, knowing that AFB1 is metabolized by cytochrome P450 (CYP), our aim was to develop a method to detoxify A. flavus-contaminated maize, under normal temperature and pressure, using Escherichia coli expressing human CYP3A4. First, the metabolic activity of AFB1 by recombinant human CYP3A4 was evaluated. As a result, we confirmed that recombinant human CYP3A4 metabolizes 98% of AFB1. Next, we found that aflatoxin Q1, a metabolite of AFB1 was no longer mutagenic. Furthermore, we revealed that about 50% of the AFB1 metabolic activity can be maintained for 3 months when E. coli expressing human CYP3A4 is freeze-dried in the presence of trehalose. Finally, we found that 80% of AFB1 in A. flavus-contaminated maize was metabolized by E. coli expressing human CYP3A4 in the presence of surfactant triton X-405 at a final concentration of 10% (v/v). From these results, we conclude that AFB1 in A. flavus-contaminated maize can be detoxified under normal temperature and pressure by using E. coli expressing human CYP3A4.