• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.279-283
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• 2011

The immature embryos during seed development were examined to predict the suitable embryos for an efficient regeneration system. Five spring wheat genotypes and five winter wheat genotypes were tested using immature embryos as explants. Spring wheat genotypes showed much higher levels of plant regeneration than those of winter wheat genotypes. The highest frequencies of embryogenesis and regeneration were obtained when embryos at 13-14 days after anthesis (DAA) were used as explant and decreased using embryos at 21-22 DAA during seed development. Significant differences were also found for callus induction and regeneration as affected by immature embryo size. The regeneration efficiency was drastically decreased in spring and winter wheat genotypes when embryos larger than 2.0 mm of length were used. The optimum developmental stage and embryo length for regeneration efficiency were at 13-14 DAA and 1.0-1.5 mm, respectively. The selection of suitable embryos for the high frequencies of embryogenesis and regeneration leads us to efficient genetic improvement of wheat.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.231-233
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• 2003

Agricultural land use generally shows specific temporal characteristics of NDVI obtained from satellite data. In terms of winter wheat, a higher value compared with other land use types in May and a considerably low value in June could be discriminative features of temporal change of NDVI. In this study, the author examined methods for estimating winter wheat sown area in sub-pixel level of coarse resolution satellite data using temporal characteristics of NDVI. Application of the methods to the major grain production area in China exhibited properly a spatial distribution pattern of winter wheat sown area.

• Plant Breeding and Biotechnology
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• v.2 no.3
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• pp.224-230
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• 2014

Amplified fragment length polymorphism (AFLP) is a molecular marker technique based on DNA and is extremely useful in detection of high polymorphism between closely related genotypes like Korean wheat cultivars. Six sequence characterized amplified regions (SCARs) have been developed from inter simple sequence repeat (ISSR) analysis which enabled the identification and differentiation of 13 Korean wheat cultivars from the other cultivars. We used six combinations of primer sets in our AFLP analysis for developing additional cultivar-specific markers in Korean wheat. Fifty-eight of the AFLP bands were isolated from EA-ACG/MA-CAC, EA-AGC/MA-CTG and EA-AGG/MA-CTA primer combinations. Of which 40 bands were selected to design SCAR primer pairs for Korean wheat cultivar identification. Three of 58 amplified primer pairs, KWSM006, KWSM007 and JkSP, enabled wheat cultivar identification. Consequently, 23 of 32 Korean wheat cultivars were classified by eight SCAR marker sets.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.18-28
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• 2021

The growth period and productivity of cropping system of winter wheat-rice, winter wheat-bean and winter wheat-grain corn for 4 years from 2015 to 2018 were compared at the experimental field of National Institute of Crop Science in Miryang city. The harvest period of winter wheat was in mid-June, and summer crops were sown (transplanted) in late June. In transplanting of rice in late June, there was no difficulty in securing the heading of panicle and the yield of rice, but there was a lot of trouble in sowing wheat in proper time because the harvest time of rice was delayed to early November due to late maturity of rice, particularly in the mid-late maturing cultivar. There was no problem in soybean planting after winter wheat because the proper period of soybean planting is late-June. In addition, there was no problem in winter wheat sowng after soybean because the maturity period of soybean was mid-October. Selection of grain maize in double cropping with winter wheat in terms of growing periods, was desirable because grain maize had the fastest maturity among summer crops. In double cropping of winter wheat-summer crops, wheats combined with soybean and grain maize showed stable yields during three years, but there was a risk of yield declines in the wheat combined with rice in heavy rainfall year. It was possible to secure high yields in three summer crops as yields of rice, soybean, and corn were 600, 350, and 800 kg/10a, respectively. Summer crops with medium maturity was recommended because of no significant difference in yield between medium maturity and medium-late maturity cultivar. Soil physical properties were improved in soils cultivated with soybean and grain maize. Therefore, It was thought that double cropping systems of winter wheat with soybean and grain maize were superior to that of winter wheat with rice in terms of connecting period between winter wheat - summer crops and improvement of soil physical properties, and total income, particularly in soybean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.93-100
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• 1985

Five winter and five spring wheat cultivars of diverse genetic backgrounds were evaluated to examine different developmental responses in terms of stages of the life cycle and grain yield when grown under the different planting dates. Greatest difference in growth and developmental patterns of the winter and spring wheat cultivars occurred in stem elongation, booting, inflorescence emergence and anthesis. The growth stage of stem elongation was found to exhibit larger difference both among planting dates and cultivars. Winter wheat cultivars responded more than spring wheat cultivars to the different planting dates. Winter wheat 'Cho Kwang' and spring wheat 'Jugoku 81' were earlier and exhibited faster growth and development, while winter wheats 'Yamhill' and 'Hyslop' were later in growth and development, but exhibited faster grain filling and higher rate of grain filling, resulting in higher grain yields. Crosses between winter and spring wheat gene pools would result in earlier maturity and higher productivity for both winter and spring wheat cultivars. For developing early maturing wheat cultivars for multiple cropping sequences while maintaining productivity, selection for earliness trait should be started at the stem elongation stage. Furthermore, the breeding materials should be planted at several times for selection of shorter life cycle genotypes adaptable to the cropping sequences. This is due to the genotype x planting date interactions.

• The Plant Pathology Journal
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• v.35 no.1
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• pp.63-70
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• 2019

Winter wheat is susceptible to several fungal pathogens throughout the growing season and foliar fungicide application is one of the strategies used in the management of fungal diseases in winter wheat. However, for fungicides to be profitable, weather conditions conducive to fungal disease development should be present. To determine if winter wheat yield response to fungicide application at the flowering growth stage (Feekes 10.5.1) was related to the growing season precipitation, grain yield from fungicide treated plots was compared to non-treated plots for 19 to 30 hard red winter wheat cultivars planted at 8 site years from 2011 through 2015. At all locations, Prothioconazole + Tebuconazole or Tebuconazole alone was applied at flowering timing for the fungicide treated plots. Grain yield response (difference between treated and non-treated) ranged from 66-696 kg/ha across years and locations. Grain yield response had a positive and significant linear relationship with cumulative rainfall in May through June for the mid and top grain yield ranked cultivars ($R^2=54%$, 78%, respectively) indicating that a higher amount of accumulated rainfall in this period increased chances of getting a higher yield response from fungicide application. Cultivars treated with a fungicide had slightly higher protein content (up to 0.5%) compared to non-treated. These results indicate that application of fungicides when there is sufficient moisture in May and June may increase chances of profitability from fungicide application.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.129-136
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• 2009

This study was to optimize the harvest time of several winter cereal forage crops. Barley, rye, oat, triticale and wheat were evaluated for the quantity and quality of hay and silage at four different harvesting stages, including heading, 10 days after heading (DAH), 20 DAH and 30 DAH. Barley and wheat harvested at 20 DAH, and oat and triticale at 30 DAH showed maximum dry matter yield. Crude protein content of barley, wheat, triticale and oat decreased significantly with advancing crop maturity. Mean crude protein content was the highest in rye and the lowest in oat. The NDF and ADF content of barley, wheat, triticale and oat decreased with late harvest, while rye increased. Maximum total digestible nutrients (TDN) content was recorded in barley and wheat harvested at 20 DAH, in triticale and oat at 30 DAH, and in rye at heading. The maximum TDN content of silage, 66.98%, was recorded in barley, followed by wheat, triticale, oat and rye. However, The crude protein, NDF and ADF of silage was 1 to 4 times higher than those of hay. In this study, barley harvested at 20-25 DAH, wheat and triticale at 30 DAH, and rye at heading provided a good compromise between dry matter yield and forage quality. At this stage, a sufficient quantity of fodder with moderate forage quality was obtained.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.172-178
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• 1998

Freezing-resistant plants can survive subzero temperatures by withstanding extracellular ice formation. During cold acclimation, their leaves accumulate antifreeze proteins (AFPs) that are secreted into the apoplast and have the ability to modify the normal growth of ice crystals. Three barley, two wheat and two rye cultivars were grown under two different temperature regimes (20/16$^{\circ}C$ and 5/2$^{\circ}C$, day/night). Apoplastic proteins from winter cereals were separated by SDS-PAGE and detected with antisera to AFPs from winter rye. Apoplastic proteins accumulated to much higher levels in cold-acclimated (CA) leaves compared with nonacclimated (NA) ones in winter cereals. After cold acclimation, the protein concentration of apoplastic extracts increased significantly from 0.088 $mgmL^{-1}$ to 0.448 $mgmL^{-1}$, with about 5-fold increment. Also, the apoplastic protein content per gram leaf fresh weight in CA leaves ranged from 31 $\mu\textrm{g}$ $(gFW)^{-1}$ to 120 $\mu\textrm{g}$ $(gFW)^{-1}$ with an averaged value of 77 $\mu\textrm{g}$ $(gFW)^{-1}$, and coefficients of variation of 54.9%. The CA leaves in Musketeer (a Canadian winter rye cultivar) showed the greatest AFPs and antifreeze activity followed by 'Geurumil' (a Korean winter wheat cultivar), and 'Dongbori l' (Korean facultative barley cultivar). The proteins secreted into the wheat leaf apoplast at CA condition were more numerous than those observed in winter rye, where two $\beta$-1,3-glucanase-like proteins (GLPs), two chitinase-like proteins (CLPs) and two thaumatin-like proteins (TLPs) accumulated during cold acclimation. The proteins in barley leaf apoplast at CA conditions were a little different from those in wheat leaves. The AFPs were various among and within species. More freezing-resistant cultivars had more clear and numerous bands than less freezing-resistant ones. The high determination coefficient ($R^2$ =91 %) between freezing resistance and AFPs per gram leaf fresh weight indicated that the amount of AFPs was highly related to freezing resistance in winter cereal crops.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.5
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• pp.352-359
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• 2001

Cookie baking properties and relationships between cookie baking properties and flour characteristics were evaluated for two years, 1997 and 1998, and at two locations, Suwon and Deokso, with Korean winter wheat cultivars and lines. Cookie baking parameters, except for cookie diameter and top grain score, were influenced by locations and years. Chokwang, Suwon 274, Suwon 275, Suwon 277 and Urimil showed larger cookie diameter and excellent top grain score compared to the other Korean winter wheat cultivars and lines. Among the flour characteristics, protein content, damaged starch content, alkaline water retention capacity and flour swelling volume showed high positive correlation coefficients with cookie baking parameters. Friabilin-present lines showed larger cookie diameter, suitable surface structure of cookie and softer snapping force than the friabilin-absent lines.

• The Plant Pathology Journal
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• v.30 no.1
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• pp.25-32
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• 2014

Fusarium head blight (FHB; scab) caused mainly by Fusarium graminearum is a devastating disease of wheat and barley around the world. FHB causes yield reductions and contamination of grain with trichothecene mycotoxins such as deoxynivalenol (DON) which are a major health concern for humans and animals. The objective of this research was to develop an easy seed or seedling inoculation assay, and to compare these assays with whole plant resistance of twenty-nine Korean winter wheat cultivars to FHB. The clip-dipping assay consists of cutting off the coleoptiles apex, dipping the coleoptiles apex in conidial suspension, covering in plastic bag for 3 days, and measuring the lengths of lesions 7 days after inoculation. There were significant cultivar differences after inoculation with F. graminearum in seedling relative to the controls. Correlation coefficients between the lesion lengths of clip-dipping inoculation and FHB Type II resistance from adult plants were significant (r=0.45; P<0.05). Results from two other seedling inoculation methods, spraying and pin-point inoculation, were not correlated with adult FHB resistance. Single linear correlation was not significant between seed germination assays (soaking and soak-dry) and FHB resistance (Type I and Type II), respectively. These results showed that clip-dipping inoculation method using F. graminearum may offer a real possibility of simple, rapid, and reliable for the early screening of FHB resistance in wheat.