• Korean journal of applied entomology
• /
• v.20 no.2 s.47
• /
• pp.117-121
• /
• 1981

The screening method of varietal resistance on the plant hoppers has generally been evaluated as a reaction of plant after infesting insects. However, feeding amount of insects to the varieties was investigated in this experiment. The new method using isotope $^{32}P$ for rice varietal resistance to plant hoppers was carried out through the following method. Insects tested were caged for a few hours on the plants which had absorbed $^{32}P$ solution in small vials for $24\~48\;hours$. After feeding, insects were killed in the refrigerator with formalin solution, and then were measured by the feeding amount as a count per minute (CPM) with the G.M. Counter. The results obtained were summarized as follows; 1. The apparatus of Type D(Fig. 2) was most effective and the safest among four others. 2. The optimum amount of $H_3PO_4$ solution was found to be $2\~3m1$. 3. Radioactivity of $0.7\mu\;Ci.\;^{32}P$ was sufficient to check varietal difference of feeding amount by the brown planthopper. 4. Radioisotope was found from the body of insects but not in the cuticular layer nymphs cast off.

• Research in Plant Disease
• /
• v.13 no.3
• /
• pp.131-136
• /
• 2007

Occurrence of popcorn disease on mulberry fruits was surveyed in several locations in Korea from 2005 to 2007. The diseased fruits turned grayish white and changed to hard and black sclerotia during overwintering after falling onto the ground. Apothecia produced from overwintered sclerotia in the fields of mulberry trees were observed in early May. Two types of apothecia were produced from the sclerotia, which were cup-shaped or club-shaped. The fungus with cup-shaped apothecia was identified as Ciboria shiraiana, and that with club-shaped apothecia as Scleromitrula shiraiana. C. shiraiana occurred at the ratio of about 6 vs. 4 in the fields. Occurrence of the disease differed remarkably depending on years, locations, and varieties of mulberry trees investigated. Field survey of the disease incidence showed that Baekhahyeongsang, Dahojosaeng, Hasusang, a native variety and Sawonppong 22 were resistant to the disease, Cheongilppong, Daeseongppong, Guksang 20 and Turkey-D were moderately susceptible, and Cateneo, Moreji and Sanggwa were highly susceptible. Disease incidence in the fields mulched with nonwoven fabrics or plastic films was much lower than that in the non-mulched fields. Disease incidence in the fields mulched with rice straws was similar to that in the non-mulched fields.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.3
• /
• pp.245-251
• /
• 2014

Sorghum seed is traditionally used as health supplements and the secondary food mixed with rice in Korea. While the research of reserve protein in sorghum seed have been carried out in many countries used as major food, much less is known about reserve proteins of Korean local sorghum seeds. To obtain protein characteristics in 20 Korean local sorghum seed, quantitative content of reserve protein was determined after fractionation by modified 'Osbone' method and ${\alpha}$-kafirin of prolamin was determined by SDS-PAGE. Mean albumin, globulin, prolamin and glutelin contents based on total seed protein content of 20 Korean local sorghum seed were 6.2%, 0.9%, 57.9% and 35.1%, respectively. Sorghum cultivar with high prolamin were 'Whin-susu', 'Whin-Chalsusu', 'Whanggeum-Chalsusu', and 'Daepungshushu'. Sorghum cultivar with high ${\alpha}$-kafirin were 'Whin-susu', 'Geumsan-Chalsusu', 'Whin-Chalsusu', and 'Jangmok-susu'. Among the 20 varieties, 'Whin-susu' and 'Whin-Chalsusu' were selected as high ${\alpha}$-kafirin and prolamin sorghum cultivar, which showed 64.5 and 71.9% of prolamin contents, respectively.

• Korean Journal of Ecology and Environment
• /
• v.33 no.3 s.91
• /
• pp.311-318
• /
• 2000

The purpose of this study was to determine the optimum water intaking depth for water treatment plant based on the changes of phytoplankton distributions in Unmun reservoir. Sampling was carried around of intaking tower near the Dam site at monthly intervals from February to Ocotber in 1998. Total 79 phytoplankton taxa were observed and they were classified into 4 varieties, 75 species within 51 genera. Diatoms were mainly dominated from February to July. However Rhodomonas sp. was a dominant species in August, and Microcystis ichthyblabe in September and October. Cell density of 122,800 cells/mL in October was the highest, and 415 cells/mL in May was the lowest. The pattern of vertical distribution was similar until May; however, the cell density in the epilimnion was much higher than it in the hypolimnion during the periods with the high water temperature over $20^{\circ}C$ since June. The water depths showing over 5,000 cells/mL ranged from the surface to 9m in June, surface to 6m in September, and on the only surface in October. Based on water temperature and phytoplankton vertical distribution, the depth of 6m appeared to be the optimum intaking depth far water treatment plant: 75.4 to 98.0% of phytoplankton cell densities could be avoided and the temperature over $18.3^{\circ}C$ was preserved to prevent cold water damage for rice growth at the water depth during cyanobacterial blooming period in Unmun reservoir.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.32 no.2
• /
• pp.208-214
• /
• 1987

A genetic study on the panicle characters in Oryza sativa was carried out by means of a 5 x 5 diallel cross. The five parental varieties were Raekyung, Yeongnamjosaeng, Nongbaek, Yushin and Honenwase. All characters were correlated positively each other, except number of kernels per primary branch. The number of secondary branches per primary branch.was the most effective factor in determining the number of kernels per panicle, the next being the number of primary branches per panicle. Regression analyses of the data of Vr/Wr indicated the presence of non-allelic gene interactions for all characters. Overdominant characters were the number of kernels per panicle, the number of primary branches per panicle, the number of secondary branches per primary branch, the number of kernels per primary branch and sum of kernels on all the tertiary branches per panicle, suggesting that the characters were more influenced by dominant effect than additive effect. However, the number of kernels per secondary branch was partially dominant where the genetic variation was due more to additive effect than to dominance effect. But after omitting the parent which had non-allelic interaction gene, the characters; the number of kernels per panicle, the number of secondary branches per primary branch, and the number of kernels per secondary branch, were partially dominant. Narrow sense heritabilities(h$^2$ N) in number of kernels per panicle and number of secondary branches were high and moderate, respectively, but those of the rest were lower. Mean squares of GCA and SCA of all characters, except SCA of the number of kernels per secondary branch, were highly significant. Effects of GCA were larger than SCA effects in all characters. Raekyung, Yushin and Nongbaek had highly positive GCA, and the best positive SCA was observed in crosses of Nongbaek x Tongillines (Raekyung, Yushin, and Yeongnamjosaeng) in all characters.

• Korean Journal of Food Science and Technology
• /
• v.35 no.3
• /
• pp.335-341
• /
• 2003

The physicochemical characteristics and chemical compositions of six Korean traditional soybeans were studied namely, cheongtae, seoritae, jinjoori, subaktae, yutae and huktae. The characteristics of imported soybean were also investigated for comparison. The average weight of one hundred-seed for huktae, which is normally used as nutritional supplement by adding to rice during cooking, was 43.1 g. The average whole length and long and short width for six varieties of the bean were $5.68{\sim}10.15\;mm$, $5.10{\sim}9.33\;mm$ and $4.30{\sim}7.48\;mm$, respectively. Color of cheongtae and subaktae were green, while that of seoritae, jinjoori, and huktae were black with yutae having yellow seed coat. Moisture, crude fat, crude protein and ash content of soybean seeds were all in the ranges of $8.5{\sim}11.5%$, $14.0{\sim}20.8%$, $38.0{\sim}49.2%$ and $4.2{\sim}5.0%$, respectively, showing differences among cultivars. Methionine, cysteine and histidine were the minor components of soybean protein and percentage of methionine to the total proteins showed significant varietal differences. Subaktae contained the highest content of methionine with 4.0 mg/g protein, while jinjoori the lowest with 1.8 mg/g protein. The main fatty acids of total lipid were linoleic, oleic and palmitic acids, which comprised over 80% of total fatty acids. Cultivar yutae had higher content of neutral lipid but lower content of glycolipid and phospholipid. Among the fatty acids, content of linoleic acid were the highest $(41.4{\sim}54%)$ and ratios of unsaturated fatty acid to the total fatty acid was $82.7{\sim}85.2%$. The main fatty acid of neutral lipid, glycolipid, and phospholipid was linoleic acid.

• Korean journal of applied entomology
• /
• v.20 no.3 s.48
• /
• pp.173-175
• /
• 1981

New screening method of varietal resistance by isotope $^{32}P$ was examined in these experiments. Insects were fed for 24 hrs. in the vials, with rice seedlings absorbed the solution if $0.6\~7{\mu}\;Ci\;^{32}P$ for 24 to 48 hrs. Feeding amounts of 3 species of plant-hoppers at the different stages and duration of infestation were investigated for effective process of screening method of the varietal resistance using isotope $^{32}P$. Feeding amount of $^{32}P$ of brown plant-hopper was observed for the different varieties. The results may be summarized as follows: 1. Brown planthopper fed greatest and the feeding amount were increased in order of white-backed planthopper and small brown planthopper. Female hoppers fed more than male. 2. Feeding amount was increased in order of adult, 5th instar, adult, 4th instar, 3rd instar 2nd instar and 1st instar. The duration of $24\~48\;hours$ is considered sufficient for insect infestation. 3. New screening method by $^{32}P$ was compared with seedling bulk screening method in view of feeding amount and plant reaction. Feeding amount of $^{32}P$ by brown planthopper in Milyang 47, resistant variety to this insect, was very low, while in TN 1, susceptible variety, it was very high about one hundred tines of Milyang 47.

• Molecules and Cells
• /
• v.25 no.3
• /
• pp.417-427
• /
• 2008

Comparison of maps and QTLs between populations may provide us with a better understanding of molecular maps and the inheritance of traits. We developed and used two reciprocal $BC_1F_1$ populations, IP/DS//IP and IP/DS//DS, for QTL analysis. DS (Dasanbyeo) is a Korean tongil-type cultivar (derived from an indica x japonica cross and similar to indica in its genetic make-up) and IP (Ilpumbyeo) is a Korean japonica cultivar. We constructed two molecular linkage maps corresponding to each backcross population using 196 markers for each map. The length of each chromosome was longer in the IP/DS//IP population than in the IP/DS//DS population, indicating that more recombinants were produced in the IP/DS//IP population. Distorted segregation was observed for 44 and 19 marker loci for the IP/DS//IP and IP/DS//DS populations, respectively; these were mostly skewed in favor of the indica alleles. A total of 36 main effect QTLs (M-QTLs) and 15 digenic epistatic interactions (E-QTLs) were detected for the seven traits investigated. The phenotypic variation explained (PVE) by M-QTLs ranged from 3.4% to 88.2%. Total PVE of the M-QTLs for each trait was significantly higher than that of the E-QTLs. The total number of M-QTLs identified in the IP/DS//IP population was higher than in the IP/DS//DS population. However, the total PVE by the M-QTLs and E-QTLs together for each trait was similar in the two populations, suggesting that the two $BC_1F_1$ populations are equally useful for QTL analysis. Maps and QTLs in the two populations were compared. Eleven new QTLs were identified for SN, SF, GL, and GW in this study, and they will be valuable in marker-assisted selection, particularly for improving grain traits in tongil-type varieties.

• Journal of Sericultural and Entomological Science
• /
• v.53 no.2
• /
• pp.71-77
• /
• 2015

Much attention has been focused on the activity of the natural antioxidants present in fruits and vegetables, because potentially these components may reduce the level of oxidative stress. Especially, mulberry leaves containing many natural components are considerable resource for natural antioxidants. The antioxidant capacity of mulberry leaves was investigated with minilum L-100 device and ARAW-KIT (anti-radical ability of water-soluble substance), in comparison to the ascorbic acid. The antioxidant capacity of 16 varieties was 3303.4 nmol at opening stage of five leaves in spring. The highest stage of antioxidant capacity (3708.0 nmol) and yield rate was just before the coloration stage with anthocyanin in fruits, whereas the lowest stage was middle of June (2231.6 nmol) and about two months growing stage after summer pruning (2064.6 nmol). But after summer pruning, the antioxidant capacity of mulberry leaves increased gradually until just before fallen leaves stage. Even if samples were same variety, antioxidant effect of those showed different results according to collected regions. Also, antioxidant effect of mulberry leaves were higher than that of branches. The antioxidant capacity of yield-type mulberry leaves and fruits (Morus alba L., M. bombycis Koidz, and M. Lhou (Ser.) Koidz) collected from In-je, Won-ju and Yang-yang regions, Kang-won province, Korea, was investigated. The results indicated that total antioxidant capacity of yield-type mulberry leaves was 2711.2 nmol. In the antioxidant capacity analysis of Jeollabuk-Do genetic resources, autumn's mulberry leaves showed higher antioxidant capacity than that of spring's it. To investigate the effect of tea on antioxidative capacity, five kinds of tea(coffee mix, green tea added brown rice, mulberry leaf tea, Polygonatum odoratum tea and black tea added lemon) were selected and analyzed. Their's anti-oxidative capacity were 2,531.01 nmol, 1,867.42 nmol, 1,053.72 nmol, 292.71 nmol and 188.91 nmol, respectively. The antioxidative capacity of drinking water soaked with mulberry leaf showed 891.96 nmol.

• Korean Journal of Remote Sensing
• /
• v.37 no.5_1
• /
• pp.1199-1206
• /
• 2021

Accordingly, attention is also being paid to the agricultural use of remote sensing technique that non-destructively and continuously detects the growth and physiological status of crops. However, when remote sensing techniques are used for crop monitoring, it is possible to continuously monitor the abnormality of crops in real time. For this, standard growth information of crops is required and relative growth considering the cultivation environment must be identified. With the relationship between GDD (Growing Degree Days), which is the cumulative temperature related to crop growth obtained from ideal cultivation management, and the vegetation index as standard growth information, compared with the vegetation index observed with the spectralreflectance sensor(SRS_NDVI & SRS_PRI) in each rice paddy treated with standard cultivation management and non-fertilized, it was quantitatively identified as a time series. In the future, it is necessary to accumulate a database targeting various climatic conditions and varieties in the standard cultivation management area to establish a more reliable standard growth information.