‘Alchanheukchal’ is a single-cross hybrid waxy corn cultivar developed by using the inbred line ‘KBW16’ as the seed parent and ‘KBW23’ as the pollen parent. Yield trials were conducted in 2013 and 2015 followed by regional adaptability tests at six locations over three years (2018-2020). Recognized for its superior performance, it was designated as a new variety by the NICS in 2020. ‘Alchanheukchal’ contains 32.9 μg 100 g^-1 of anthocyanins, resulting in black-colored ears and exhibiting an intermediate ear shape. Its silking period was 74 days, equivalent to that of the standard variety ‘Ilmichal’. The ear length was 19.3 cm, similar to ‘Ilmichal’, while the kernel set rate was 94%, which was lower than that of ‘Ilmichal’. In terms of disease and pest resistance, including southern rust, northern corn leaf blight, and corn borer, as well as lodging resistance, ‘Alchanheukchal’ was comparable to ‘Ilmichal’. The number of ears and ear weight per 10a were 6,336 ears and 1,136 kg, respectively, which indicates a higher ear number but lower ear weight than ‘Ilmichal’. The 100-kernel weight was 27.7 g, smaller than that of ‘Ilmichal’. In sensory evaluation tests, the overall acceptability score was 4.7, which was lower than that of ‘Ilmichal’. The highest seed production efficiency was observed when the planting ratio of the seed parent to pollen parent was 2:1. However, because the silking date of the pollen parent occurred later, it was considered necessary to perform staggered sowing (Registration No. 10033).

Here, we report on the development of a high-quality, bicolor waxy corn, ‘Mihyeonchal’, containing anthocyanin. ‘Mihyeonchal’ was produced by crossing the two inbred lines, HW18 as the seed parent and HW19 as the pollen parent. The hybrid was made in 2016 and has been evaluated for three years in Hongcheon, Yeoncheon, Cheongju, Daegu, Jinju, and Suwon in Korea since 2017. The days to silking of ‘Mihyeonchal’ was 72 days, which was three days earlier than that of the standard variety, ‘Ilmichal’. The number and weight of fresh ears of ‘Mihyeonchal’ were 112% and 96%, respectively, compared to those of ‘Ilmichal’, and the anthocyanin content was 76.8 mg/kg, which was higher than that of ‘Ilmichal’. The lodging index was 1.9, which was weaker than that of ‘Ilmichal’, but its resistance to insects and diseases was stronger than that of ‘Ilmichal’, confirming the cultivation stability of ‘Mihyeonchal’. As a result of regional yield trials that had been conducted for three years, we confirmed that ‘Mihyeonchal’ could be cultivated in all regions in Korea and was an excellence variety. The plant variety protection right of ‘Mihyeonchal’ was registered in April 2024, and its grant number is 10127.

We report the development of a high quality red waxy corn ‘Mihongchal’, containing anthocyanin. Mihongchal was produced by crossing two inbred lines, ‘HW9’ as seed parent and ‘HCW5’ as pollen parent. The hybrid was created in 2016 and evaluated in Hongcheon, Pyungchang, and Yeongwol for 3 years. Mihongchal days to silking was 72 days and the other agronomic characteristics were similar to ‘Mibaek 2ho’. Mihongchal yield was slightly lower than ‘Mibaek 2ho’. Fresh ears number and weight were 93 and 91% compared to ‘Mibaek 2ho’, respectively but anthocyanin content was 1,160 mg/kg, which is higher than ‘Mibake 2ho’. Resistance to insects, diseases, and lodging was similar to ‘Mibaek 2ho’. Due to the analysis, it was recognized as functional waxy corn with high quality characteristics and anthocyanin content. Since regional yield tests was performed in only Gangwon State, it is recommended only in that region for cultivation. Mihongchal is a resource with excellent taste and functionality that can increase the value of waxy corn. The chosen variety was termed ‘Mihongchal’, its plant variety protection right was registered in February 2023 (Registration No. 9354).

‘Baeksoojeongchal’, a new naked waxy barley cultivar was developed from a cross between ‘Jinmichapssal’ and ‘Radiant’ at the National Institute of Crop Science, RDA in 2019. ‘Baeksoojeongchal’ is a white, waxy naked barley cultivar with a low browning reaction owing to the low levels of proanthocyanidin. Regional yield trials were conducted for ‘Baeksoojeongchal’ as the breeding line, ‘Jeonju135’ at four different regions between 2017 and 2019. The average heading date of ‘Baeksoojeongchal’ in the paddy field was April 20, which was a day later than that of ‘Saechal’. Maturing date of ‘Baeksoojeongchal’ in the paddy field was May 26, which was 2 days later than that of ‘Saechal’. It has a short culm length of 75 cm and a short spike length of 4.3 cm, with 48 grains per spike and a 1,000-grain weight of 29.5 g. Compared to ‘Saechal’, ‘Baeksoojeongchal’ shows weaker winter withering and has better tolerance to lodging. The incidence of BaYMV (Barley yellow mosaic virus) in ‘Baeksoojeongchal’ was similar to that in ‘Saechal’; in addition, it was susceptible to powdery mildew. The grain quality characteristics of ‘Baeksoojeongchal’ indicated a similar protein content (9.6%) and a lower proanthocyanidin content (0.011%) and whiteness (42.0) compared to that in ‘Saechal’. The average yield was 505 kg/10a in the paddy field, which was 7% higher than that of ‘Saechal’. ‘Baeksoojeongchal’ is the naked waxy barley cultivar with the most whiteness and low proanthocyanidin content; therefore this could contribute to the promotion of barley consumption, by avoiding reduction in consumer preference (Registration No. 9194).

The sorghum (Sorghum bicolor (L.) Moench) variety ‘Noeulchal’ was developed and registered by the Department of Southern Area Crop Science, National Institute of Crop Science, in 2019. This variety was developed from the cross between ‘RTx2907’, with white grain, and ’Sodamchal’, with brown grain and semi-dwarf traits. The yield performance of ‘Noeulchal’ was 3.71 MT/ha in a local adaptability test run for two years. It had a culm length of 93 cm, which is 11 cm longer than that of ‘Sodamchal’, a panicle length of 29 cm, a culm 22 mm thick, and a panicle exsertion of 9 cm. It could reduce the lodging problem experienced with current cultivars, and is also adapted to mechanized cultivation. ‘Noeulchal’ has a waxy endosperm with 3.2% amylose and contained high levels of rapidly digestible starch. The rapidly digestible starch with gluten-free flours could contribute to the development of foods with different properties (Registration No. 9105).

‘Jangsuheukchal’ waxy corn was developed through single-cross by Gyeonggido Agricultural Research and Extension Services in 2012. The seed parent inbred ‘GMB0016’ was crossed with the pollen parent inbred ‘GMB0017’ in 2010. ‘Jangsuheukchal’ took 72 days to silking, which was 4 days sooner than ‘Miheukchal’, and ‘Jangsuheukchal’ was 195 cm in height, which was 12 cm less than that of ‘Miheukchal’; the occurrence of lodging was low in the new species. Among the ear characteristics, the kernel setting rate was very high (99%), and the grain pericarp thickness was slightly more than that of ‘Miheukchal’, but the sensory evaluation was positive because of the high amylopectin content and the fine ear appearance. The regional yield trials were conducted in four areas for two years in 2011-2012, and the density of fresh ears for ‘Jangsuheukchal’ was determined as 62,280 ears/ha, which was 6% higher than that of ‘Miheukchal’, but the weight of the fresh ears was 9,178 kg/ha, which was 17% lighter than its counterpart. In order to diversify the use of fresh waxy corn, the cooking properties of milled waxy corns were investigated and compared to ‘Mibaek2’, which was the main cultivar in Gyeonggido province in 2018. The grain yield per ha of ‘Jangsuheukchal’ was 5,600 kg, which was 12% less than that of ‘Mibaek2’, but after harvesting fresh ears, the grain yield per ha was 1,060 kg, which was 10.6 times more than the known cultivar. In addition, compared to ‘Mibaek2’, ‘Jangsuheukchal’ showed excellent processing characteristics in the cooking properties for milled kernels because of its light 100-seed weight, low protein content, and high starch content. Therefore, we report ‘Jangsuheukchal’ as a new variety, suitable for use as a fresh corn and possessing the cooking properties of milled kernels (Registration No. 6065).

‘Hwanggeummatchal’, a yellow waxy corn hybrid obtained by crossing inbred ‘KY37’ and ‘KY29’, was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA, Korea, in 2017. The number of days to silking of ‘Hwanggeummatchal’ was 69 days after planting, 2 days earlier than ‘Ilmichal’ (a control variety). Plant height of ‘Hwanggeummatchal’ was 205 cm, lower than that of the control, and ear height ratio was 49%, which was lower than that of ‘Ilmichal’. Lodging resistance of ‘Hwanggeummatchal’ was similar to ‘Ilmichal’. The fresh ear yields were 6,389 ears in 10 a. The carotenoid content of ‘Hwanggeummatchal’ was 16.4 μg 100 g^-1 fresh weight, which was much higher than that of ‘Ilmichal’. The pericarp thickness was 41 μm. The sensory evaluation value was 5.7, and the flavor was excellent. The flowering period of its parental lines was well matched, and seed production was best at a planting ratio of maternal and paternal lines, 3:1. ‘Hwanggeummatchal’ is suitable to the whole country, except for Jeju-do. Seeds of ‘Hwanggeummatchal’ must be renewed annually because it is a single cross hybrid. If this hybrid is cultivated under high-density conditions, the ear size and the ratio of kernel set length to ear length will be lower than that of standard cultivation. Pest control should be performed for this hybrid because it is susceptible to corn borer (Registration No. 8136).

In this study, 14 agricultural and phenotypic traits were used to analyze morphological variations among 10 near-isogenic lines (NILs) of colored waxy maize and 2 parental lines (HW3 and HW9) of the hybrid cultivar “Mibaek 2.” The results of principal component analysis indicated that on the first principal component axis, seed coat color, R value, V value, days of tasseling, L* value, and days of silking greatly contributed to the positive direction, whereas anthesis–silking interval and leaf width greatly contributed to the negative direction. On the second principal component axis, kernel row number and tassel color contributed to the positive direction, whereas setted ear length, ear length, and 100-kernel weight contributed to the negative direction. Thus, the morphological characteristics that greatly contributed to the first and second principal components might be useful for discrimination among the 10 NILs and 2 parental lines of “Mibaek 2.” Of the 10 NILs analyzed, 16CLP26 and 16CLP16 were considered useful breeding material for the development of colored waxy maize varieties with relatively high amounts of yield and anthocyanin. Collectively, these results are expected to provide useful information for the development and selection of lines for breeding colored waxy corn varieties at the Maize Research Institute, Gangwon-do Agricultural Research and Extension Services.

“ Nulichal” was developed by the National Institute of Crop Science, RDA, in 2010. The initial cross was conducted in 2000, and an elite line (HB15305-B-B-31-2) was selected in 2005. Subsequently, preliminary yield and advanced yield trials have designated it as “Iksan 95.” It showed good agronomic performance in regional yield trials from 2008 to 2010 and was released as “Nulichal,” with resistance against the barley yellow mosaic virus (BaYMV) and high yields with a waxy endosperm. The average heading and maturation dates of “Nulichal” were April 24 and May 30, respectively in paddy fields, which were 1 day later than those of the check cultivar “Saechalssalbori.” It had culm and spike lengths of 82 and 4.0 cm, respectively. It showed 774 spikes/m², 63 grains/spike, 25.0 g of 1,000-grain weight, and 793 g of test weight. “Nulichal” showed higher levels of resistance to BaYMV than the naturally occurring Iksan (type III strain), Naju (type Ⅰ), and Jinju (type II). The expansion rate was higher than that of “Saechalssalbori” and its hardness, gumminess, and chewiness were lower than those of “Saechalssalbori.” Its average pearled grain yield in the regional yield trial was 4.00 MT/ha in paddy fields, which was 10% higher than that of the check cultivar. The combined availability of “Nulichal” was improved by its increased culm length compared with that of “Hinchalssal.”

Hwangmichal, a yellow waxy corn hybrid, is a single cross hybrid developed in 2014. This hybrid was created by crossing the seed parent KY30 and pollen parent KY9. Hwangmichal has yellow kernels with a conico-cylindrical ear shape. The days to silking of Hwangmichal were similar to that of Ilmichal, a check hybrid. The ear height ratio of Hwangmichal was 50%, which was lower than that of Ilmichal, and its number of tillers was less than that of Ilmichal. The ear size of Hwangmichal was smaller than that of Ilmichal and the kernel set ratio was 89%. Its sensory evaluation was better than that of Ilmichal. The carotenoid content of Hwangmichal was 32.2 µg/g, which was much higher than that of Ilmichal. Lodging resistance of Hwangmichal was better than that of Ilmichal. Although the number of fresh ears of Hwangmichal was more than that of Ilmichal, the weight of fresh ears was lower than that of Ilmichal. The flowering period of its parent lines was well matched and seed production was 3:1 at a planting density of parent lines of more than 2:1. It is adaptable to the whole country except for Jeju-do. The plant variety protection right of Hwangmichal was registered in June 2017, and its grant number is 6728.

Consumer interest in nutrition and health has increased, for other food and industrial applications, including for barley. ‘Huknuri’ is a new naked non-waxy barley cultivar with black lemma. It was developed by the National Institute of Crop Science, RDA, in 2011. The initial cross was carried out in 2002, and an elite line (HB16225-B-B-9) was selected in 2006. Since then, through preliminary yield and advanced yield trials, it was designated as ‘Iksan 100’. It showed good agronomic performance in the regional yield trials from 2009 to 2011 and was released as ‘Huknuri’, possessing high anthocyanin content and black lemma with a non-waxy endosperm. The average heading and maturing dates of ‘Huknuri’ were April 23 and May 29 in paddy fields, which were one day earlier and the same as those of the check cultivar ‘Saessalbori’, respectively. It had a culm and spike length of 87 and 5.0 cm, respectively. It showed 601 spikes per m², 61 grains per spike, 29.0 g of 1,000-grain weight, and 780 g of test weight. ‘Huknuri’ showed better resistance to Barley yellow mosaic virus and higher water absorption and expansion rates than those of the check cultivar. Its average pearled grain yield in the regional yield trial was 3.44 MT/ha in upland, and 3.56 MT/ha in paddy fields, which were 5% lower and 1% higher than those of the check cultivar, respectively. The anthocyanin content was 180 µg/g, which was higher than that of the check cultivar.

Consumers currently prefer healthy food with antioxidant or anti-diabetic activities. This study was conducted to develop a waxy corn with high carotenoid content. A yellow waxy corn single cross hybrid ‘Goldchal’ was developed by Gangwon Agricultural Research and Extension Services in 2015. The seed parent inbred HW16 was crossed with the pollen parent inbred HW17 in 2010. The number and weight of fresh ears per 10 a for ‘Goldchal’ were 6,385 and 1,339 kg, respectively, comparable to those of ‘Ilmichal’ in regional yield trials from 2013 to 2015. The hybrid contained 15.8 mg/kg carotenoids, which were 15.0 mg/kg higher than that of ‘Ilmichal’. The lodging tolerance of ‘Goldchal’ was superior to that of ‘Ilmichal’ and resistance to disease and insects was similar to those of ‘Ilmichal’. The silking date of the seed parent HW16 was in the pollen dispersal period of the pollen parent HW17, and F₁ seed yield was 186 kg/10a. ‘Goldchal’ could be cultivated throughout Korea. The plant variety protection right of ‘Goldchal’ was registered in June 2017 (Grant Number 6722).

A new waxy corn single cross hybrid ‘Jangsuchal’ was developed by Gangwon Agricultural Research and Extension Services in 2014. The seed parent inbred HW12 was crossed with the pollen parent inbred HW15 in 2009. Days to silking of ‘Jangsuchal’ was three days later than ‘Ilmichal’, a check hybrid. Ear length of the hybrid was 22.2 cm, which was 2.8 cm greater than ‘Ilmichal’. The hybrid had thin pericarp thickness, high amylopectin content, and high value of sensory evaluation compared with ‘Ilmichal’. Resistance to disease and insect and lodging tolerance of ‘Jangsuchal’ were similar to those of ‘Ilmichal’. The number and weight of fresh ears for ‘Jangsuchal’ were greater than those of ‘Ilmichal’ in regional yield trials from 2012 to 2014. Silking date of the seed parent HW12 was in the pollen dispersal period of the pollen parent HW15 and F₁ seed yield was 242 kg/10a. ‘Jangsuchal’ can be planted anywhere in the country. Plant variety protection right of ‘Jangsuchal’ was registered in June 2017 with grant number of 6730.

This study was carried out to select waxy corn inbreds with good general combining ability through a diallel analysis of 10 half diallel crosses among five inbreds developed from Korean maize landraces. Total of 21 agronomic and palatability traits were investigated over two locations in 2016. There was a significant hybrid by location interaction found in plant height, ear height, number of tillers/plant, per ear weight, ear tip filling, ear commercial value and sweetness when four additional check cultivars were included in the analyses. A significant general combining ability by location interaction was found in ear height, number of tillers/plant, per ear weight, ear length and sweetness while ear width, ear commercial value and sweetness were significant for specific combining ability by location interaction. Sweetness was found significant for both interactions. The first and fourth inbred lines had the most number of traits with good estimate of general combining ability. The first inbred is expected to improve days to tasseling, anthesis silking interval, ear width, ear circumference and sweetness while decreasing husk cover in a hybrid combination. The fourth inbred line would improve days to tasseling, days to silking, plant height, ear height, per ear weight and ear length but ears would be a bit tougher than the average. A total of 19 traits had higher variance of general combining ability than that of specific combining ability. Husk cover was 12.1 times higher. Plant height and number of tillers/plant had higher variance of specific combining ability.

This study was conducted to compare changes of total carotenoid contents and antioxidant activities in yellow waxy corns (Zea mays L.) depending on harvest time. The total carotenoid contents of yellow waxy inbred lines and hybrids increased from 19 days and then the highest content of total carotenoid contents was observed at 25 to 27 days after pollination. Thereafter, there was little change in total carotenoid contents. According to analysis total content of carotenoids on 23 days after pollination, which was the period of harvesting waxy corn, KY2 was the highest as 15.4 ㎍/g in inbred lines and KY2/KY39 was the hightest as 11.2 ㎍/g in hybrids, respectively. The total carotenoid contents of each hybrid were higher than mean that of their parent lines except for some hybrids. The total carotenoid contents of KY27/KY37 were significantly higher than those of their parental lines. Antioxidant activity of yellow waxy corn showed a tendency to increase after decrease depending on delaying harvesting time. Antioxidant activities of hybrids were higher than that of inbred lines. As a result of correlation analysis between total carotenoid contents and antioxidant activity, correlation coefficient of inbred lines and hybrids was as low as -0.12 and -0.13, respectively. When the harvest time was delayed, the lightness of yellow waxy corn decreased but the redness and yellowness increased. As a result of correlation analysis between Hunter’s Lab value and total carotenoid contents, correlation coefficient of lightness, redness and yellowness were -0.22, 0.67, 0.53, respectively.

The sorghum (Sorghum bicolor (L.) Moench) variety ‘Sodamchal’ was developed and registered by Department of Sothern Area Crop Science, National Institute of Crop Science (NICS) in 2013. This variety was developed from the cross between ‘Hwanggeumchal’ with brown grain and ’Jungmo4001’ with semi-dwarf trait. ‘Sodamchal’ is the first semi-dwarf stature with waxy endosperm ever developed in Korea. The yield performance of ‘Sodamchal’ was 2.95 MT/ha in local adaptability test for 2 years. It had 91 cm culm length, which was 58 cm shorter than that of ‘Hwanggeumchal’, 26.3 cm panicle length, 22.0 mm thickness of culm, 21.1 g in 1,000 grain weight. It could be reduce the lodging problem and also adapted to mechanized cultivation. ‘Sodamchal’ produces high quantities of polyphenol and radical scavenging activitiy with diphenyl-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in pigmented testa. Above all ‘Sodamchal’ is suitable for use as a parental source for the development of improved pollinator parent lines for developing semi-dwarf sorghum with waxy endosperm and antioxidant activity. (Variety registration No. 6244)

The sorghum (Sorghum bicolor (L.) Moench) variety ‘Sodamchal’ was developed and registered by Department of Sothern Area Crop Science, National Institute of Crop Science (NICS) in 2013. This variety was developed from the cross between ‘Hwanggeumchal’ with brown grain and ’Jungmo4001’ with semi-dwarf trait. ‘Sodamchal’ is the first semi-dwarf stature with waxy endosperm ever developed in Korea. The yield performance of ‘Sodamchal’ was 2.95 MT/ha in local adaptability test for 2 years. It had 91 cm culm length, which was 58 cm shorter than that of ‘Hwanggeumchal’, 26.3 cm panicle length, 22.0 mm thickness of culm, 21.1 g in 1,000 grain weight. It could be reduce the lodging problem and also adapted to mechanized cultivation. ‘Sodamchal’ produces high quantities of polyphenol and radical scavenging activitiy with diphenyl-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in pigmented testa. Above all ‘Sodamchal’ is suitable for use as a parental source for the development of improved pollinator parent lines for developing semi-dwarf sorghum with waxy endosperm and antioxidant activity. (Variety registration No. 6244)

This study was carried out to create new waxy corn variety using anthocyanins germplasm including 13 ornamental maize stocks, purple corn and two parental lines of Mibaek2. First, we made anthocyanin husk population for sustainable breeding from 13 ornamental stocks for 6 years from 2001 and then crossed purple corn with a dark purple kernel in 2007. We crossed this hybrid with two parental lines of Mibaek2, a good edible quality waxy corn, in 2007/2008 dry season nursery for additional breeding in Thailand. The anthocyanin-rich waxy lines derived from these hybrids were self-fertilized seven times and made single cross hybrids until 2011. These hybrids were evaluated on 2 or 3 places in Gangwon-do for next two years. One selected elite hybrid was named Cheongchunchal and applied for registration of new waxy corn variety in March 2014. Total anthocyanins content is zero in Mibaek2, 737 in Miheugchal, 18,809 mg/kg in Cheongchunchal. This variety is meaningful as health food and high-value industrial material.

A ‘Hayanchal95’, a new waxy corn hybrid, is a single cross hybrid developed by the maize breeding team at the National Institute of Crop Science (NICS), Rural Development Administration(RDA) in 2011. This hybrid was made by crossing between seed parent KW44 and pollen parent KW35. Days to silking of Hayanchal95 was three days earlier than Ilmichal, a check hybrid. Ear length and diameter of Hayanchal95 were 18.3 cm and 4.1 cm, respectively. The ratio of kernel set length to ear length was 90% and lower than Ilmichal. Its quality characteristics like amylopectin content, hardness of kernels, and value of sensory evaluation were not significantly different from Ilmichal except grain length. Resistance to corn borer and lodging tolerance of Hayanchal95 were better than Ilmichal. The number of fresh ears was similar to those of Ilmichal and weight of fresh ears was lower than Ilmichal in regional yield trials (RYT) from 2009 to 2011. Although flowering time of its parent lines was good match during crossing between the seed and pollen parents, seed production was low. It is adaptable to the whole country. Plant variety protection right of ‘Hayanchal95’ was registered in July 2014, and its grant number is 5110.