• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.1
• /
• pp.8-13
• /
• 2011

This study was carried out to compare botanical characteristics, physicochemical properties related to table quality and feed values and develop a new variety among 12 developed waxy com hybrids. These materials were produced in 2008 and cultivated in 2009 at Com Breeding and Genetics Farm of Coll. of Agri. & Life Sci., Chungnam Nat'l Univ. Botanical characteristics of used waxy com hybrids showed large difference among hybrids; stem height, ear height and ear length. In physical properties, range of kernel sugar content among used hybrids appeared 16.1 to 13.0brix(%). CNU08H-15, CNU08H-35 and CNU08H-h39 among these were highly appeared as 15 above and pericarp thickness of Yeonongchal was very thick as $46.0{\mu}m$, while CNU08H-39 among hybrids showed the thinnest as $23.0{\mu}m$ compared to other hybrids. Protein content as a indicator of table quality was the highest in Ilmichal among hybrids, while that of CNU08H-39 was the lowest, while amylopectin content was the highest as 94.5%, From experimental results, Daehakchal Gold 1, CNU08H-h121 and CNU08H-39 including check Yeonyoungchal were highly evaluated as new hybrid in thinner pericarp, high amylopectin and chewiness.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.4
• /
• pp.464-469
• /
• 2015

This study was carried out to find relationships of genetic distance and heterosis expression degree in the developed CNU waxy corn lines. The used material were developed in Corn Breeding Laboratory, Coll. of Agri. & Life Sci., CNU. Total 10 primers used for SSR maker analysis. In genetic distance, the used lines divided into four groups; A group has two lines, B group has one line, C group has ten lines and D group has eleven lines, respectively. Among used lines, CNU427 and CNU588 were very closed as a 74, while CNU451 and CNU429 were remote as a 40 inbred coefficient, respectively. While heterosis degree were very variable not only hybrids but also cross parents. Average heterosis of most cross-parent was high in plant height, ear height, flowering day and ear length. Especially, CNU H09-23 hybrid was high as 79.4% than other hybrids. Here, we gained the fact has closely relationship between genetic distance and heterosis.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.3
• /
• pp.308-317
• /
• 2015

The aim of the present study was to investigate the ear and kernel characteristics of colored waxy corn hybrids during ripening according to different sowing dates. Heukjinjuchal and Eolrukchal 1 were sown at April 20 (first cropping) and July 20 (second cropping) in 2011~2012. The accumulated temperature from silking to harvesting was about $590{\sim}610^{\circ}C$. It takes 23~24 days when Heukjinjuchal and Eolrukchal 1 were sown in April 20, but July 20 sowing takes 32~35 days. Ear weight, ear diameter, 100-kernel weight and starch content of colored waxy corn were increased as ears matured (p<0.05). Growth temperature was getting decreased during the ripening stage of second cropping, the rate of ear and kernel development had slowed. Starch granules started to accumulate in the cells around the pericarp, then developed in the cells around the embryo. In the second cropping, starch granules in the kernel of colored waxy corn were less compact than the first cropping. The contents of total anthocyanins, cyanidin-3-glucoside and pelargonidin-3-glucoside were increased according to ripening (p<0.05). These results will be helpful to farmers for double cropping of colored waxy corn cultivation and management.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.1
• /
• pp.24-30
• /
• 2010

Comprehensive studies on seedling production and transplanting cultivation of waxy corn are necessary to fulfill the comsumer's preference for the high quality whole ear waxy corn and its year-round supply for higher price, and to escape marketing in a short period at harvest season. Two waxy corn hybrids (cv. Chalok# 1 and Chalok# 4) were used to study the effects of seeding date, nursery days and plug cell size on growth and yield of waxy corn, and to clarify the reliable transplanting date at the Experimental Field of the National Institute of Crop Science in 2007. The number of days from seeding to silking was increased as nursery days were extended, but the number of days from transplanting to silking was shortened comparing to the direct seeding. Number of days from seeding to silking was shorter by 9~12 days for Chalok# 1 than for Chalok# 4, while the number of days from seeding to silking was shorter by 12~15 days in the second cropping than in the first cropping. Culm length of transplanted waxy corns was decreased as the nursery days were extended. Culm length of seeded Chaok# 1 and Chaok# 4 were decreased by 17% and 24%, respectively, in the second cropping compared to those in the first cropping. Ear length was somewhat decreased as the nursery days were extended. Chalok# 1 in the second cropping the degree of decrease was much higher in second cropping than in first cropping of Chalok# 1. Comparing to the first cropping, number of marketable ears per 10a of Chalok# 1 decreased as high as 64%, while that of seeded Chalok# 4 decreased mere 12% in the second cropping.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.2
• /
• pp.195-201
• /
• 2012

It is important to determine the optimum harvesting time that impact decisively on the quality of vegetable waxy corns. In general, it takes 20~25 days from silking to harvest according to ecotype when waxy corn hybrids were sown in April. We identified the optimum harvesting time by the ecotypes and seeding dates for the establishment of corn double cropping system of waxy corn. It takes 23~25 days from silking to harvest regardless of ecotype, when waxy corns were sown at early in April or late in June. It takes 28~31 days when Chalok1, early maturing type, was sown between in July 10, and in July 30. It takes 29~31 days when Ilmichal, medium late maturing type, was sown between in July 10 and in July 20, but 39 days were required when sown at in July 30. The cumulative temperature for harvesting was about $1700^{\circ}C{\sim}2100^{\circ}C$. The minimum cumulative temperature from seeding to harvest was approximately $600^{\circ}C$. These results will be helpful to the farmers for determining the optimum harvest time of vegetable waxy corns.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.54 no.4
• /
• pp.407-415
• /
• 2009

To investigate the effects of seeding date, nursery days and plug cell size on seedling growth and quality of waxy corn. This study was carried out in the field of the National Institute of Crop Science in 2007. Varieties used were two waxy corn hybrids cvs. Chalok# 1 and Chalok# 4. The plant height, number of leaves and dry weight of waxy corn seedlings were significantly affected by seeding dates and plug cell size, while no differences between varieties. The growth of seedlings was faster in March 14 seeding than in May 8 and July 4 seedings. Based on plant height, March 14 seeding, May 8 seeding and July 3 seeding reached suitable size for transplanting after 30 days (21.6cm), 15 days (25.5~26.9cm) and 10 days (21.6~24.0cm) in the nursery, respectively. Seedlings of March 14 seedling and May 8 and July 3 seeding reached suitable number of leaves i,e. 2~3 leaves, 15~20 days after seeding on March 14 and 10 days after seeding on May 8 and July 3. Dry weights of 30 days seedling for March 14 seeding, 20 days seedling for May 8 seeding and 15 days seedling for July 3 seeding were 0.43g, 0.57~0.67g and 0.53g, respectively, and the dry weight of seedlings increased by 2~3 folds at the later nursery days. The suitable nursery days of waxy corn were 20 days on March 14 seeding and 10~15 days on May 8 or July 3 seeding.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.6
• /
• pp.392-399
• /
• 2000

This study was carried out to investigate the physicochemical characteristics of corn silks. Pollination of corn silks was finished within three days after silking, and elongation of open pollinated corn silks was stopped, but unpollinated silks elongated until eight days after silking. Moisture contents of corn silks were about 92-94% at silking stage, but continuously decreased. these were about 70-75% at 30 days after silking. Chlorophyll b was higher than chlorophyll a in corn silks, and chlorophyll a/b ratios of four hybrids were high in this order : silage ＞ sweet ＞ super sweet ＞ waxy corn. Free sugars in corn silks were mainly fructose, glucose and maltose. Their composition rate was 55% of glucose, 42% of fructose and 4% of maltose. Water soluble solid (Brix %) contents of unpollinated corn silks were ranged from 13.7 to 16.8 Brix % and pollinated corn silks were from 12.6 to 13.7 Brix %. Phytic, oxalic, malic. shikimic, glutaric and acetic acid were detected on corn silks. Phytic, oxalic and glutaric acid were considered as a major organic acids in corn silks. Amino acids in corn silks were high in this order : waxy ＞ silage ＞ sweet ＞sweet corn. Serine, glycine and thereoine were contained more than 10%, and five amino acids such as aspartic, glutaric, arginine, alanine and proline were ranged about 5 to 8%. Methionine and cystine, amino acids containing sulfur were contained only small quantity as about 2.1% and 1.3%, respectively. Acetaldehyde, ethanol, acetone, DMS, isobutylaldehyde, cis-3-hexanol, 3-hexe-1-ol, acetate, trans-2-hexanol and pentanol were detected as the volatile components in corn silks, but acetaldehyde and DMS were major volitiles in silage corn silks, and acetaldehyde, ethanol and DMS were major volitiles in waxy corn silks. The length of corn silks was a positively correlated with organic acids (r=${0.556}^*$), and a negatively correlated with amino acids (r=${-0.514}^*$), respectively. Free sugars were positively correlated with all characteristics tested and significantly correlated with organic acid (r=TEX>${0.703}^{**}$), and flavonoids (r=TEX>${0.544}^*$). Chlorophyll was significantly correlated with flavonoid contents (r=TEX>${0.523}^*$). For this reason chlorophyll was evaluated as an indirect selection character for the high flavonoid containing varieties.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.2
• /
• pp.85-91
• /
• 2000

Antioxidant activity and related components including tocopherols, phenolic compounds and carotenoids in the corn(Zea mays L.) kernels were measured to understand effects of fertilizer application. Hybrids used were Chalok 2, a waxy corn, and Suwon 19, a dent corn. The standard fertilizer level of N-P-K was 14.5-3-6 for Chalok 2 and 17.4-3-6.9 for Suwon 19. The treatments of the fertilizer levels were the standard level, half and two fold amounts of N, P, and K, and no fertilizer. The antioxidant activity was determined by measuring electron donating ability. The antioxidant activity of Chalok 2 was higher than Suwon 19. The antioxidant activity was the highest at the standard fertilizer treatment for Chalok 2, but was statistically not significant. The antioxidant activity and the related compounds content in Suwon 19, however, were the highest in the two fold nitrogen treatment, and the differences were significant. The contents of tocopherols, phenolic compounds and carotenoids were 30.0~38.1, 104.7~118.8, $0.1{\mu}gml^{-1}$, respectively for Chalok 2 and 16.7~20.1, 59.9~72.7, $35.5{\sim}50.0{\mu}gml^{-1}$, respectively for Suwon 19. The antioxidant activity was positively correlated with the grain yield in both cultivars. The shorter the ASI the higher the yield of the plant. The difference in genetic factors would affect greater influence than fertilizer effect on the antioxidant activity of corn.

• Korean Journal of Agricultural Science
• /
• v.4 no.2
• /
• pp.215-228
• /
• 1977

In order to provide good germplasm for developing good corn hybrids, a total of 948 Korean indigenous corn lines were collected from various parts of country and major morphological characterstics of ears were investigated. The results obtained were as follows; 1) Ear Type; From the east-north mountaionus region where more than 80% of total corn production is practiced, cylinder (type I) or similar types to cylinder corn were collected, and from the southern plain region, where rather small scales of corn is grown, cone type (type IV) or similar types to cone were prevalent. 2) Kernel color; In the ear colors of all the indigenous corn lines collected from ten regions, ears with mono color were 54.4%, ears with two color mixed were 39.0% and ears with three or more color mixed were 6.6%. In northern mountainous region, region A and region I, ear color was mostly white or white plus other colors, while in other regions ear color was yellow or yellow plus other colors. 3) Denting; Dent type was only 4.3% of Korean indigenous corn lines collected, and others were flint type. Dent type was collected from northern regions, where foreign corn varieties were introduced and grown. 4) Ear row number; Ear row numbers of indigenous corn lines collected were 12 to 16. There was no significant differences among the ear row numbers in a ear ciassified by regions. However, it was observed that ear row number was closely related to kernel size. For instance, the ears with 24 ear-rows were the smallest in kernel size. 5) Quality of starch; 70.9% of the indigenous corn lines collected were kernels with hard starch. Corn with soft starch was 26.0% and medium type was 3.1%. In region A and region I, where lot of corn is grown, corn with hard starch was more frequently collected. 6) Pop corn and waxy corn; In all the indigenous corn lines collected, popcorn was distributed uniformly through the regions except region I, and waxy corn was found more in the northern mountainous region. 7) Ear length; The mean ear length of indigenous corn lines collected was 13cm. In region A and region I ear length was larger than that in other regions. 8) Ear diameter; The mean ear diameter of indigenous corn lines collected was 3.3cm. In region A and region I ear diameter was larger than that in other regions. 9) Kernel length, kernel width and kernel thickness; The mean kernel length, kernel width and kernel thickness of indigenous corn lines collected were 0.82cm, 0.42cm, and 0.78cm, respectively. The kernel size in the region A and region I was larger than that in other regions. 10) Ear weight; The mean ear weight of indigenous corn lines collected was 58.04gr. Ear weight was remarkably heavier in region A and region I. The heaviest ear weighed 330gr, and the lightest ear weighed 5 gr. 11) Kernel weight of a ear and 100 kernel weight; Kernel weight of a ear and 100 kernel of indigenous corn lines collected were 47.07gr and 15.07gr, respectively. Kernel weights and 100 kernel weights were much heavier in region A and region I than other regions.