National Institute Of Crop Science Research Articles

"Nulichal" Barley Extract Suppresses Nitric Oxide and Pro-Inflammatory Cytokine Production by Lipopolysaccharides in RAW264.7 Macrophage Cell Line.

The cultivar "Nulichal," a type of naked waxy barley (Hordeum vulgare L.), was developed by the National Institute of Crop Science, Rural Development Administration, Korea, in 2010. In this study, we investigated the anti-inflammatory and antioxidant properties of the "Nulichal" ethanol extract (NRE) using various assays. The NRE exhibited a total phenolic content of 7.55±0.30 mg gallic acid equivalent/g and a flavonoid content of 1.74±0.08 mg rutin equivalent/g. Cell viability assays showed no toxicity of NRE on RAW264.7 macrophage cells up to concentrations of 500 μg/mL. The NRE (300 and 500 μg/mL) significantly reduced nitric oxide (NO) production induced by lipopolysaccharides (LPS). It also down-regulated the mRNA expression and protein levels of inducible NO synthase and cyclooxygenase-2 in a dose-dependent manner. Moreover, the NRE treatment significantly decreased the levels of pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin-6, and their mRNA expression compared to LPS treatment alone. The NRE demonstrated strong free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals in a dose-dependent manner. The ferric reducing antioxidant power assay also showed increased antioxidant activity with increasing NRE concentrations. These findings suggest that the NRE can be used as a functional food with anti-inflammatory and antioxidant properties.

First report of post-harvest tuber rot of Apios americana Medikus caused by Penicillium expansum in South Korea.

Apios americana Medikus, a perennial vine legume native to North America, is known as 'Indian potato' or 'Apios' for their underground tubers that are used for human consumption in Korea (Choi et al., 2017). These tubers are known to be rich in isoflavones as well as other secondary products to have known several medicinal properties (Chu et al., 2019). The harvested tubers in 2020 were observed to rot during storage of tubers for 4 months at 4°C in the genetic resource storage room at the Bioenergy Crop Research Institute, National Institute of Crop Science, Muan, Jeollanam-do, South Korea. The incidence of rot symptoms with blue mold was less than 1% per 20 kg box. Ten infected tubers were collected from several boxes and the lesions were cut into small pieces, and then surface sterilized in 1.5% NaClO for 2 minutes, followed by rinsing 3 times with sterilized water. To investigate their morphological characteristics, ten isolates were cultured in Malt Extract Agar (MEA) medium at 25° C for 5 days (Pitt and Hocking, 1988). The surface morphology of the mycelium had white or light green fluffy, and completely blue spores were formed after about 5 days. The conidia were one-stage branched with an elliptical shape, about 3.5 to 4.3 × 2.9 to 3.6 (mean 3.8 ± 0.3 × 3.2 ± 0.2) ㎛ in diameter (n=30). Genomic DNAs of the isolates were extracted using Solgent DNA Extraction Kit (Solgent, Daejeon, Korea), and then PCR products of the internal transcribed spacer (ITS1/ITS4) region and the beta-tubulin gene (Bt2a/Bt2b) were sequenced and analyzed (Glass and Donaldson, 1995). The BLASTn showed that the representative isolate had 99% homology with reference Penicillium expansum strain ICMP 2708 (ITS region and TUB2 gene) in NCBI GenBank. The sequences of the isolate were deposited in GenBank as accession numbers MZ636667 and MZ702813 for ITS and TUB2 genes, respectively. Based on the morphological characteristics and molecular analysis, the isolate was identified as P. expansum. Pathogenicity assays of the isolate were also performed using three tubers in three replicates inoculated with spore suspension (concentration, 1×106 conidia/mL) and compared with a control group inoculated with sterilized water. The inoculated Apios tubers were placed in a plastic box maintained in conditions of high humidity at 25°C. Five days after inoculation, the typical symptoms were observed on inoculated tubers, and no symptoms were observed in the control one. P. expansum was again isolated from artificially inoculated tubers to complete Koch's assumption. This is the first report of P. expansum causing tuber rot in A. americana in South Korea. As the cultivated area of Apios is increasing in Korea, it will be necessary to develop effective storage methods and management strategies for the control of storage diseases such as blue mold.

The Semi-dwarf Grain Sorghum (Sorghum bicolor L. Moench) Variety ‘Noeulchal’, with Increased Digestibility

Other SectionsAbstractThe 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).Keywords : Sorghum bicolor L., Semi-dwarf, Noeulchal, Waxy endosperm, Variety

High-amylose and Tongil type Korean rice varieties: physical properties, cooking behaviour and starch digestibility.

The National Institute of Crop Science, Rural Development Administration (RDA) of Korea is presently developing new rice varieties suitable for producing Western rice-based foods, such as risotto, a well-known Italian-style product. The study considered different milled rice from five Tongil-type and six Japonica-type varieties. Besides the biometric properties, cooking behaviour, starch properties, and in vitro digestibility of Korean rice samples were compared with those of the 'Carnaroli' Italian variety. The physicochemical traits of the Korean varieties extended over a vast range; the amylose content stood out (from 13.0 to 41.7%), influencing the hardness and stickiness of cooked samples, and their starch digestibility. Although none of the Korean varieties seemed to guarantee cooking performances for risotto similar to the 'Carnaroli' one, 'Saemimyeon' and 'Shingil' cvs were judged the best for this purpose up-to-now.

A Malting Barley (Hordeum vulgare L.) Variety, ‘Baegrok’with Resistance to Powdery Mildew and Tolerance to Lodging

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceA new malting barley variety, ‘Baegrok’, was developed in 2016 at the National Institute of Crop Science, RDA: Rural development administration by crossing the high-yield ‘Milyang130’ variety with ‘Myoginijo’, which has lodging tolerance and resistance to barley yellow mosaic virus (BaYMV). ‘Baegrok’ is suitable for use in brewing, similar to ‘Hopum’, and has resistance to powdery mildew and tolerance to lodging. From 2014 to 2016, regional yield trials were conducted in four different regions, with ‘Baegrok’ as a breeding line of ‘Iksan176’. The heading dates of ‘Baegrok’ in paddy and upland fields were April 6 and April 11, respectively, 2 days earlier than those of ‘Hopum’. Maturing dates of ‘Baegrok’ in paddy and upland fields were May 16 and May 21, respectively, similar to those of ‘Hopum’. The yield potential of ‘Baegrok’ was approximately 14% and 6% higher than that of ‘Hopum’ in upland and paddy fields. ‘Baegrok’ had a shorter culm length than ‘Hopum’ showing tolerance to lodging. Screening for powdery mildew resistance in the greenhouse showed that ‘Baegrok’ had resistance to powdery mildew, unlike ‘Hopum’ which was susceptible. It also is suitable for use in brewing, similar to Hopum. ‘Baegrok’ showed good grain quality in terms of β-glucan content (3.4%), starch (61.0%), and husk rate (12.7%). Regarding malt quality, ‘Baegrok’ exhibited 75.1% acrospire length, 70.8% friability, 4.4% soluble protein, and 345.8 WK (Windisch-Kolbach) diastatic power, superior to the malt quality of ‘Hopum’. Thus, ‘Baegrok’ is resistant to powdery mildew, tolerant to lodging, and more suitable for brewing. (Registration No. 8399)Keywords : malting barley, variety, malt, powdery mildew, lodging

An Adzuki Bean (Vigna Angularis) Cultivar ‘Honggyeong’ with Bright Red Seed-Cort Color and Resistance to Lodging Stress

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceIn 2008, a new adzuki bean (Vigna angularis) cultivar, ‘Honggyeong’, was developed using artificial cross between ‘Milyang 7 (SA9709-2B-8-2-4-4-1)’ and ‘SA0001’ at the National Institute of Crop Science, RDA, Korea. It was selected for further yield trials-named ‘Miryang 36’. This cultivar was prominent and showed desirable agronomic traits, such as lodging tolerance, high yield, and high antioxidant activity during the regional adaptation yield trials (RYT) from 2016-2018. ‘Honggyeong’ was finally released as a new cultivar in 2018 and its distinct phenotypic traits included a semi-determinate growth habit, yellow flowers, green embryonic axis, bright red seed-cort color, white hilum, and large seeds (18.4 g per 100 seeds). The average yield of ‘Honggyeong’ was 2.06 MT/ha in the regional yield trials (RYT), which was slightly higher than that of the check cultivar (1.89 MT/ha), ‘Chungju’ (Registration No. 7934).Keywords : Vigna angularis, Adzukibean, Honggyeong, Lodging resistance, Milyang 36

Effects of drought stress on root morphology and spatial distribution of soybean and adzuki bean

Due to global climate change, Korea is facing severe droughts that affect the planting and early vegetative periods of upland crops. Soybean and adzuki bean are important legume crops in Korea, so it is critical to understand their adaptations to water stress. This study investigated the changes in root morphological properties in soybean and adzuki bean and quantified the findings using fractal analysis. The experiment was performed at the National Institute of Crop Science in Miryang, Korea. Soybeans and adzuki beans were planted in test boxes and grown for 30 days. The boxes were filled with bed soil with various soil moisture treatments. Root images were obtained and scanned every two days, and the root properties were characterized by root length, depth and surface area, number of roots, and fractal parameters (fractal dimension and lacunarity). Root depth, length and surface area and the number of roots increased in both crops as the soil moisture content increased. The fractal dimension and lacunarity values increased as the soil moisture content increased. These results indicated that the greater the soil moisture, the more heterogeneous the root structure. Correlation analysis of the morphological properties and fractal parameters indicated that soybean and adzuki bean had different root structure developments. Both soybean and adzuki bean were sensitive to the amount of soil moisture in the early vegetative stage. Soybean required a soil moisture content greater than 70% of the field capacity to develop a full root structure, while adzuki bean required 100% of the field capacity. These results would be useful in understanding the responses of soybean and adzuki bean to water stress and managing irrigation during cultivation.

Characterization of Wind-Tolerant Rice Varieties Bred at the National Institute of Crop Science

Characterization of Wind-Tolerant Rice Varieties Bred at the National Institute of Crop Science

A Small Red Bean Cultivar ‘Haeorom’ with Bright Red Seed and High Yield

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceA small red bean cultivar, ‘Haeorom’, was developed by artificial cross breeding between ‘Milyang 7 (SA9709-2B-8-2-4-4-1)’ and ‘Toyomidainagon (K204656)’ at the National Institute of Crop Science, RDA, Korea in 2008, and selected for further yield trials under the name ‘Miryang 27’. It was prevalent and showed desirable agronomic traits such as lodging tolerance, high yields, and strong antioxidant activity during the regional yield trials (RYT) from 2014 to 2016. ‘Haeorom’ was released as a new cultivar in 2016. It has some distinct phenotypic traits, including a semi-determinate growth habit, yellow flower, green embryonic axis, bright red seed, white hilum, and small spherical seeds (18.6 g per 100 seeds). The average yield of ‘Haeorom’ was 2.04 MT/ha in the RYT, which was slightly higher than that of the check cultivar (1.87 MT/ha), ‘Chungju’ (Registration No. 7508).Keywords : Small redbean, Adzukibean, Haeorom, Lodging resistance, Milyang 27

Characterizations of Growth, Yield and Water Use Efficiency of Adzuki Bean as Affected by Drought Stress

Accurate and optimal water supply to crop is critical in growing stalks and producing maximum yields. Adzuki bean is one of the representative legume crops and known as a vulnerable crop to water stress. This study investigated drought effect on adzuki bean at various growth stages and water use efficiency (WUE) with different soil moisture contents in order to evaluate response of adzuki bean to drought. The experiment was performed at National Institute of Crop Science in Miryang. Adzuki beans were planted in a Wagner pot filled with 50% of silt loam soil and 50% of bed soil. Drought treatment was applied at six growth stages: V1, V3, V5, R1, R3, R5. Another pot experiment was performed in a stainless steel pot with an automated irrigation system in order to maintain targeted soil moisture content (40, 60 and 80% of field capacity). Growth and yield characteristics of adzuki bean were measured from all pots. Crop susceptibility (CS) was calculated from the Wagner pots to quantify drought effect at each growth stage and WUE was measured from the stainless pots to determine the least water requirement to prevent drought damage. Drought effect was the greatest in growth reduction at V1 and yield reduction at R3. CS value was the smallest value at V3 and the greatest at R3. Growth, yield and WUE data of adzuki bean were not different between soil moisture 60% of field capacity and 80%, while ones from 40% soil moisture content were smaller than others. Adzuki bean exhibited great vulnerability to drought stress at reproductive stage and it required at least soil moisture 60% of field capacity to prevent drought damage. These results will be useful to water management of adzuki bean and prevent drought damage in adzuki bean cultivation. Results of daily water used from adzuki bean cultivated with different soil moisture content (40, 60, 80% of filed capacity). DAP represents days after planting.

Variation of Seed Components According to Sowing Date and Variety of Sprout Soybean in the Mid-Northern Region in Korea

Abstract Objectives Soybean(Glycine max L.) sprouts are widely used in Korea as main and sub materials in various dishes such as stew, ‘Bibimbap’, ‘Haejangguk’, and seasoned bean sprouts. The purpose of this study was to investigate the variations of general compositions and antioxidant properties in sprout soybean seed according to varieties and sowing dates in the central region of Korea, and to utilize the basic data for stable supply of raw soybeans in response to the changes in production environment. Methods Sprout soybean were produced from the experimental field of Department of Central Area Crop Science of the National Institute of Crop Science (NICS), located in Suwon, Gyeonggi-do. The sowing dates were on June 30th, July 10th and July 20th in 2018 respectively. Planting and cultivation were followed by standard soybean cultivation methods of NICS. The harvested raw sprout soybean seeds at each seeding time were ground for the general compositions analysis. Antioxidant capacity was measured with total polyphenol contents and DPPH and ABTS radical scavenging activity. Results Approximate compositions of sprout soybean seed showed significant differences according to varieties and sowing date. Moisture, crude fat, and crude protein were the highest in the first sowing date, and tended to decrease in most varieties as the seeding time was delayed, whereas carbohydrate content increased at late sowing time. DPPH radical scavenging activity showed the highest tendency in second seeding. ABTS radical scavenging activity decreased as the seeding time was delayed in the most varieties, but ‘Soyeon’ and ‘Aram’ increased in second seeding. Conclusions Taken the above results together, the significant differences in the approximate compositions and antioxidant capacities recognized due to varieties and sowing dates. Therefore, it was considered that the selection of proper varieties and sowing date should be considered carefully when growing raw sprout soybean grains in the central region in Korea. Funding Sources This study was supported by the RDA Agenda Project (project number: PJ01251603).

Productivity and quality of whole crop rice varieties in relation to plant components

AbstractTo expand the use of whole crop rice (WCR), accurate information on the nutritional value of newly developed varieties is required. We cultivated three new WCR varieties (Oryza sativa cv. Suweon 605, Yeongwoo and Mogwoo) developed by the National Institute of Crop Science in the southern Korean Peninsula and evaluated their feed value (crude protein, CP; acid detergent fiber, ADF; neutral detergent fiber, NDF; in vitro dry matter digestibility, IVDMD; total digestible nutrients, TDN; and relative feed value, RFV) and functional materials (β‐carotene and α‐tocopherol). Oryza sativa cv. Suweon 605 showed the earliest heading date and Yeongwoo the highest dry matter (DM) yield; however, there were no significant differences among varieties (p > 0.05) in DM yield. The CP content was highest in Mogwoo, and higher in leaves and grains than in stems. Oryza sativa cv. Suweon 605 had the lowest ADF and NDF contents but the highest TDN and RFV. The grain nutrient value changed drastically in all varieties by 10 days after heading. The grain ratio was highest in Oryza sativa cv. Suweon 605 at 65.6% and lowest in Mogwoo at 12.3%. The leaf β‐carotene content was 7–15 times higher than that in stems and grains, and this increase was higher in Yeongwoo (66.25 mg/kg) than those of all other measured objectives in this experiment (p < 0.05). Similar trends were observed in α‐tocopherol content. Based on these results, Oryza sativa cv. Suweon 605 is recommended in terms of feed value and Yeongwoo is recommended for its high productivity. Because the feed value changed rapidly by 10 days after heading, it is desirable to ensure a later harvest time. The effects of functional materials on livestock performance require further study.

Virginia-Typed Short Stem and Large Grain Peanut Variety ‘Tamsil’

A peanut variety ‘Tamsil’ (Arachis hypogaea ssp. hypogaea L.) was developed at the Department of Southern Area Crop Science, National Institute of Crop Science (NICS), Milyang in 2016. This was developed by crossing ‘Milyang26’ with Virginia-typed short stem and ‘Milyang20’ with Virginia-typed large grain. ‘Tamsil’, which is a Virginia plant type, has 22 branches per plant, and its main stem length is 31 cm. Each pod has two grains with brown testa and long ellipse-shaped large kernel. Its yield characteristics were as follows: pods per plant, 44; 100-seed weight, 111 g; and pod shelling ratio in the regional yield trials, 78%. The seed has 48.5% crude oil and 28.8% protein content. This variety showed resistance to early leaf spot, and it is more resistant to web blotch, stem rot, and lodging than the reference variety. In the regional yield trials for 3 years, ‘Tamsil’ was more productive than the reference variety by 19% with 4.97 MT/ha grain production.

Development of Naked Non-Waxy Black Barley (Hordeum vulgare L.) Cultivar 'Huknuri' with High Anthocyanin Content

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.

Stochastic Dominance Analysis of Revenue by Rice Cultivation Practices

This study analyzes the economic outcome of several cultivation practices of rice under uncertainty with the field data obtained from NICS(National Institute of Crop Science) from year 2014 to year 2016, where the practices include tillage, wet-direct seeding, partial tillage and no-tillage. For the analysis we adopt stochastic dominance analysis, which is basically grounded on simulation techniques and utility function with farmers’ risk attitude. The results show that farmers with risk neutral preference (r=0) always prefer wet-direct seeding practice to other alternatives irrespective of the magnitude of cost saving. The preference among alternatives, however, varies according to risk aversion coefficient and magnitude of cost saving. When farmers are risk averse (r=0.04), no-tillage practice is the most preferred alternative with cost saving from 100% to 56% but tillage practice is the most preferred alternative with cost saving less than 55%. When farmers are high risk averse (r=0.08), partial tillage practice is the most preferred alternative with cost saving from 100% to 61% but tillage practice is the most preferred alternative with cost saving less than 60%. This study is expected to be helpful to rice farmers’ decision making for the adoption of cultivation practices under the mix of risk preference and level of cost saving under uncertainty.

First Report of Maize yellow mosaic virus Infecting Panicum miliaceum and Sorghum bicolor in South Korea

Maize yellow mosaic virus (MaYMV) is a tentative new Polerovirus, which was recently identified from maize (Zea mays) in China (Chen et al. 2016). MaYMV has also been reported to infect sugarcane (Saccharum spp.) and itch grass (Rottboellia cochinchinensis), and it has been reported in Asia, Africa and South America (Goncalves et al. 2017; Palanga et al. 2017; Yahaya et al. 2017). In this study, MaYMV was detected in Panicum miliaceum and Sorghum bicolor using Illumina HiSeq2500 system by Theragen Etex Bio Institute (Suwon, Korea) and SG-VIPdb by SeqGenesis (Daejeon, Korea), as described by Lim et al. (2015). Twenty samples of P. miliaceum and sixty three samples of S. bicolor were collected from July to September and from June to October, 2016, respectively, in South Korea. The high-throughput RNA sequencing of the samples mixed into one pool resulted in a single large contig (5606-nt) with nearly complete MaYMV genome coverage. The contig was assembled from a total of 234,537 reads; the maximum, minimum...

Selection of Optimal Vegetation Indices and Regression Model for Estimation of Rice Growth Using UAV Aerial Images

Recently Unmanned Aerial Vehicle (UAV) technology offers new opportunities for assessing crop growth condition using UAV imagery. The objective of this study was to select optimal vegetation indices and regression model for estimating of rice growth using UAV images. This study was conducted using a fixed- wing UAV (Model : Ebee) with Cannon S110 and Cannon IXUS camera during farming season in 2016 on the experiment field of National Institute of Crop Science. Before heading stage of rice, there were strong relationships between rice growth parameters (plant height, dry weight and LAI (Leaf Area Index)) and NDVI (Normalized Difference Vegetation Index) using natural exponential function (R≥0.97). After heading stage, there were strong relationships between rice dry weight and NDVI, gNDVI (green NDVI), RVI (Ratio Vegetation Index), CI-G (Chlorophyll Index-Green) using quadratic function (R≤-0.98). There were no apparent relationships between rice growth parameters and vegetation indices using only Red-Green-Blue band images. RVI (Ratio vegetation index), NDVI (Normalized difference vegetation index), CVI (Chlorophyll vegetation index), gNDVI (Greent normalized difference vegetation index, CI-G (Chlorophyll Index- Geen), NGRDI (Normalized green red difference index), GLI (Green leaf index), VARI (Visible atmospherically resistant index). Relationship between vegetation indices and rice growth parameter (LAI).

Effects of Controlled Drainage Systems on Soybean (Glycine max L.) Growth and Soil Characteristics in Paddy Fields

Crop production in rice paddy fields is of great importance because of declining rice consumption and the low self-sufficiency ratio for field crops in Korea. A controlled drainage system (CDS) is recognized as an effective means to adjust water table (WT) levels as needed and control soil water content to improve the soil environment for optimum crop growth. The present study evaluated the effects of a CDS on soil characteristics, including soil water distribution and soybean development in paddy fields. The CDS was installed with two drain spacing (3 m and 6 m) at the experimental paddy field at the National Institute of Crop Science, Miryang, Korea. It was managed with two WT levels (0.3 m and 0.6 m) during the growing season. Soil water content, electrical conductivity and plant available nitrogen content in the soil were significantly greater in the 0.3 m WT management plots than in the 0.6 m plot and the control. At the vegetative stage, chlorophyll content was significantly lower with higher WT control because of excess soil moisture, but it recovered after the flowering stage. Soybean yield increased with WT management and the 0.6 m WT treatment produced the greatest grain yield, 3.38 ton ha-1, which was 50% greater than that of the control. The CDS directly influenced outflow through the drains, which significantly delayed nutrient loss. The results of this study indicated that WT management by CDS can influence soil characteristics and it is an important practice for high yielding soybean production in paddy fields, which should be considered the crop growth stages for stable crop production.

Growth and Yield Responses of Soybean to Planting Density in Late Planting

Soybean is one of the important food crop around the world. Especially in East Asia, it is the main ingredient for traditional food like soy sauce and soy paste. The double cropping system including soybean following onion, Chinese cabbage, and potato is widely adopted in Southern region of Korea. In this system, sowing date of second crop (soybean) can be delayed depending on first crops' growth period and weather condition. When planting date is delayed it is known that soybean yield is declined because of shorter vegetative growth period and earlier flowering induced by warm temperature and changes in photoperiod. The objective of this study was to determine soybean growth and yield responses as plant populations at late planting date. Field experiment was conducted at Department of Functional Crop, National Institute of Crop Science, RDA located in Miryang, Gyeongsangnam-Do for two years ('13-'14) in upland field with mid-late maturity cultivar Daewon. A split-plot block design was used with three replications. Main plots were three sowing dates from June 20 to July 20 with 15 days intervals, and subplots were 4 levels of planting densities. Data of maturity (R8) was recorded, yield components and yield were examined after harvesting. Experimental data were analyzed by using PROC GLM, and DMRT were used for mean comparison. Optimum planting population for maximizing soybean yield in late planting which compared with standard population. In mid-June planting, higher planting density causes increased plant height and decreased diameter which lead to higher risk of lodging, however, reduced growth period due to late planting alleviated this problem. Therefore higher seeding rates can provide protection against low seedling emergence caused by late planting in this region.

Evaluation on Early-maturing Korean Japonica Cultivars for High-temperature Tolerance during Grain Filling Stage

본 연구는 국내 조생종 벼 품종들과 농촌진흥청 국립식량과학원에서 육성된 자포니카(Oryza sativa L. ssp. Japonica)의 조생 다수성 품종인 남일 돌연변이 계통인 중모1024의 등숙기 고온내성을 비교 평가하여 등숙기 고온내성의 기초자료를 얻고자 수행하였다. 본 연구를 통하여 국내 조생종벼 품종들 중 대봉, 운광, 및 만안과 돌연변이 계통인 중모 1024가 고온에서 상대적으로 양호한 고온내성을 가지고 있는 것으로 평가되었으며. 특히 중모1024는 다른 공시품종들에 비하여 상당히 양호한 고온내성을 가진 것으로 평가되었다. 본 연구의 주요 결과는 등숙기간 동안 고온에 의하여 현미의 길이와 너비가 감소하였으며, 현미 너비의 감소율이 현미 길이의 감소율에 비하여 평균 4배 이상 높았다. 이러한 결과로 보아, 등숙기간 동안 고온에 의하여 현미의 길이보다는 너비가 더 많은 영향을 받는다고 사료된다. 등숙기간 동안 고온에 의해 가장 문제가 되는 완전미율과 미숙립율을 공시품종들간 비교 평가한 결과, 상대적으로 중모 1024, 태봉, 운광 및 만안이 고온에서 높은 현미완전미율을 보였으며, 상대적으로 적온에서 낮은 현미완전미율을 보인 품종들이 상대적으로 고온에 의한 현미완전미율 감소율이 적온에서 높은 현미완전미율을 보인 품종들에 비해 낮았다. 또한, 다른 공시품종들에 비하여 고온내성이 양호한 중모 1024는 고온에서도 좋은 쌀 외관품위와 안정적 수확성 향상을 위한 육종모재로서 유용형질을 교배를 통해 고품질 벼의 보완을 위해 이전할 수 있는 것이 용이할 것으로 사료된다. Early-maturing Korean Japonica cultivars and Jungmo1024 were used as plant materials to evaluate hightemperature tolerance during grain filling stage. National Institute of Crop Science (NICS) in Korea developed Jungmo1024, a mutant line from Namil (wild type) treated by using sodium azide (SA) as mutagen. To evaluate high-temperature tolerance, all cultivars were exposed to high-temperature (day <TEX>$31.5{\pm}2.5^{\circ}C$</TEX>/ night <TEX>$27.5{\pm}1.3^{\circ}C$</TEX>) and ordinary temperature (day <TEX>$27.5{\pm}1.8^{\circ}C$</TEX>/ night <TEX>$24.7{\pm}1.6^{\circ}C$</TEX>) during grain filling stage. In these conditions, we performed compared evaluation of grain shape such as length and width and grain quality by using a 1625 Cervitec grain inspector. High-temperature during grain filling stage caused decrease of grain shape. In grain shape such as length and width, the decrease rate of width (average 6.3%) was higher than the decrease rate of length (average 1.3%). Hence, high-temperature affected width of grain than length of grain. In addition, high-temperature showed a decided difference in rate of head rice between ordinary temperature (average 76.3%) and high-temperature (average 13.3%).As a result, Taebong, Ungwang, Manan, and Jungmo1024 seemed relatively a decent high-temperature tolerance than other cultivars. Especially, Jungmo1024 seemed remarkable rate of head rice (average <TEX>$34.4{\pm}6.2%$</TEX>) than other cultivars under high-temperature. It is considered that a genetic trait of Jungmo1024 can be useful to improve breeding for high-temperature tolerance.