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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Crop Science
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Journal DOI :
The Korean Society of Crop Science
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Volume & Issues
Volume 44, Issue 4 - Dec 1999
Volume 44, Issue 3 - Sep 1999
Volume 44, Issue 2 - Jun 1999
Volume 44, Issue 1 - Mar 1999
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Volatile Flavor Components of Scent, Colored, and Common Rice Cultivars in Korea
Kim, Chang-Yung ; Lee, Jong-Chul ; Kim, Young-Hoi ; Pyon, Jong-Yeong ; Lee, Sun-Gye ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 181~185
To compare the composition of volatile flavor components of three different cultivars of rice, Hyangnambyeo (aromatic cultivar), Heugjinjubyeo (pigmented cultivar) and Dongjinbyeo (normal cultivar), the volatile flavor components of brown rice were isolated by Likens-Nickerson simultaneous steam distillation and extraction apparatus. The flavor concentrates obtained were analyzed by gas chromatography and gas chromatography-mass spectrometry. A total of 65 components, including 14 aliphatic aldehydes and ketones, 7 aliphatic alcohols, 8 aromatic alcohols, 13 hydrocarbons, 9 esters, 7 aliphatic acids, and 7 miscellaneous components were identified. The aliphatic aldehydes, which are known as contributors to the overall flavor of cooked rice, were present in larger amounts in Hyangnambyeo than in Heugjinjubyeo and Dongjinbyeo, while the difference in quantity of these components between Heugjinjubyeo and Dongjinbyeo was not remarkable. Hyangnambyeo and Heugjinjubeyo contained 562 ng and 259 ng of 2-acetyl-1-pyrroline per gram of brown rice based on dry weight, respectively, which is a key compound contributing to the popcorn-like aroma in aromatic rice. Dongjinbeyo contained about 6 ng.
Effects of Trinexapac-ethyl on Lodging-related Traits in Transplanted Rice
Han, Sang-Wook ; Park, Jung-Soo ; Cho, Young-Cheol ; Lim, Gab-June ; Ju, Young-Cheoul ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 186~190
The objective of this study was to ,determine trinexapac-ethyl [4-(cyclopropyl-
-hydroxy-me-thylene)-3,5-dioxocyclohexanecarboxylic acid ethyl ester] effects on lodging-related traits of rice varieties treated at different application rates and times. Trinexapac-ethyl WP was applied at the rate of 10, 20 and 30g ai/l0a to Heukjinjubyeo and Daeanbyeo, respectively. Effects of trinexapacethyl varied greatly with application time as well as application rate with little differences between rice varieties. As the application rate increased, lodging index, center of gravity and exsertion of panicle above flag leaf decreased, whereas breaking strength and phytotoxicity increased. Exsertion of panicle was greatly influenced by the application time with a little difference by application rate. The most effective application time of trinexapac-ethyl based on lodging index and total internode length (Ist-4th node) was 2DBH(days before heading) in Heukjinjubyeo and 17DBH in Daeanbyeo, resulting in reducing total internode length by 12.9 and 9.7cm, respectively. A significant reduction was found at the 1st, 2nd, and 3rd internodes in Heukjinjubyeo, while at the 2nd and 3rd internodes in Daeanbyeo. No significant difference was found among treatments in the panicle length of both rice varieties but the panicle fresh weights of Daeanbyeo were significantly greater in all trinexapac-ethyl treatments compared with that of the control when measured 20 days after heading. Consequently, trinexapacethyl treatment significantly improved lodging-related traits of rice plants without affecting rice yield and yield components.
Agronomic Characters and Soil Nitrogen Dynamics Influenced by Barley Straw Mulch Rates in No-Tillage Direct Seeding Rice Culture
Choi, Min-Gyu ; Kang, Si-Yong ; Kim, Sang-Su ; Cheong, Jin-il ; Shin, Hyun-Tak ; Choi, Sun-Young ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 191~196
In rice-barley cropping systems, efficient utilization of barley straw is essential, both to improve the soil fertility and to conserve the environment. In order to identify the effects of barley straw mulch rates in rice cultivation, a rice cultivar, 'Gancheogbyeo', was directly seeded on a no-tillage field synchronized with barley harvesting with five barley straw mulch rates, i.e., 0, 2.5, 5.0, 7.5 and 10.0 ton h
and agronomic characters of rice and soil nitrogen were determined. The increasing of barley straw mulch rates. Dominant weed species, chestnut, occurred in large amounts in no mulching or lower mulch rates than in higher mulch rates. The content of N
-N in soil applied with high barley straw mulch rates was lower during the month after seeding, and then it was higher at heading date, compared with lower mulch rates or no mulch plot. As the barley straw rate increased, maximum tillering stage was delayed, and plant height was reduced. Although the lodging of rice plants was seldom observed in all plots, the breaking strength of the culm was significantly higher in the mulch rate of 10.0 ton h
. With an increase of barley straw mulch rate, the effective tillering rate and spikelet number
decreased while ripened grain ratio increased. The rice grain yield was slightly decreased with an increase of barley straw mulch rate, although significant differences were not found all barley straw mulch rates. These results suggest that there is no significant yield loss although the total barley straw production, approximately 5.0 ton h
in the present study, apply in the paddy for the following rice cultivation by no-tillage direct seeding.ect seeding.
Morphological Studies on Ear Characteristics of Korean Indigenous Corn Lines Collected in Pusan and Kyungnam
Lee, In-Sup ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 197~200
In order to get abundant germplasm for develop- ing new corn varieties, major morphological characteristics of ear were evaluated with a total of 210 Korean indigenous maize lines collected from various parts of Pusan City and Kyungnam Province, Korea. The ear shape of Korean indigenous maize was mainly cone type or similar to cone type. Cylinder type or similar to cylinder type of corn was collected from the north-west mountainous. region of Kyungnam Province, whereas cone type or similar to cone type was collected from the plain region. In the kernel colors of each ear, ears with mono colored kernels were 55.7% of the total, and ears with two to four mixed colors were 44.3%. Among the mono colored ears, brown was the most abundant at 16.8%. There was an average of 12∼14 rows per ear. Kernal rows per ear varied from 8∼20. Waxy corn was predominant at 67.2%, mixed corn with waxy kernel and common kernel at 11.0%, and common corn at 21.8%.
Mass Propagation of Plug Seedling using Stem Cutting and Their Tuber Yield in Potato
Park, Yang-Mun ; Song, Chang-Khil ; Kang, Bong-Kyoon ; Kim, Dong-Woo ; Ko, Dong-Hwan ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 201~206
For the mass production of plug seedlings in cultivar ‘Dejima’ potato (Solanum tuberosum L.) the optimal apical cutting diameter for rooting and rapid multiplication of stem cuttings in hydroponics were determined. In addition, the best planting date was predicted to increase tuber yield of plug seedlings at fall cropping in Cheju-Do, Korea. Days to initial rooting decreased as the cutting diameter was reduced. Plant height, leaf number, root length and root weight per plant were favorable as the cutting diameter was small. The ideal cutting diameter was 1-2 mm in this experiment. In the hydroponic cultures, the Japanese standard (JS) nutrient solution was the most effective for multiplication of stem cuttings. It was able to propagate more than 20 times a month from a single mother plant. Viability of plants, which were derived from plug seedlings using stem cuttings, was excellent when transplanted to the field. The number of tubers and tuber yield in both of the plug seedlings and seed potato planting plots were high when planted on 25 August. The number and yield were reduced when planted on 15 August, 5 September and 15 September. The degree of decrease of tuber yield in the plug seedling planting plot however, was lower than that of seed potatoes when the planting date was late. In the case of small tubers (under 30 g), the number of tubers and tuber yield were evidently increased in the seed potato tuber planting plot; the yield of large tuber (over 80g) in the plug seedling planting plot was higher than that of the seed potato. The total tuber yield per plant in the plug seedling planting plot was less than that of the seed potato; therefore, in order to increase tuber yield it was necessary to increase field plant density.
Varietal Variations in Physicochemical Characteristics and Amylopectin Structure of Grain in Glutinous Rice
Choi, Hae-Chune ; Hong, Ha-Cheol ; Kim, Yeon-Gyu ; Nahm, Baek-Hie ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 207~213
Thirty-eight glutinous rice varieties were classified into nine groups on the scatter diagram by the upper two principal components (56% contribution to the total information) based on eleven physicochemical characteristics including the viscograms and physical properties of cooked rice. The first principal component was the factor mainly associated with the viscogram characteristics of rice flour emulsion and the second was the factor chiefly related to the physical properties of cooked rice and water absorbability of rice grain. Indica glutinous rices were clearly distinguished from japonica ones by the first principal component score. Javanica glutinous rices were widely distributed on the intermediate zone between indica and japonica or on several japonica rice groups. Significant positive or negative correlations were found among water absorption rates of rice grain, physical properties of cooked rice, and viscogram characteristics of rice flour. Especially in japonica glutinous rices, the breakdown and setback viscosities of rice flour were closely associated with the alkali digestion value of milled rice and the stickiness of cooked rice. The frequency ratio of short glucose chains (A-chain) to intermediate glucose chains (B-chain), the ratio of B- chains to long glucose chains (C-chain) and the relative frequency of A- or B-chain fractions representing the amylopection structure of rice starch was closely associated with the breakdown and setback viscosities of rice flour.
Yield Potential of Improved Tropical Japonica Rice under Temperate Environment in Korea
Lee, Kyu-Seong ; Ko, Jae-Kwon ; Kim, Jong-Seok ; Lee, Jae-Kil ; Shin, Hyun-Tak ; Cho, Soo-Yeon ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 214~220
Rice production in Korea has markedly increased during the last two decades due to newly developed high yielding varieties and improved production technology. This experiment was conducted to determine the potential of tropical japonica germplasm in enhancing the yield of temperate japonica. The yield performance of two tropical japonicas (IR 65597-29-3-2 and IR66154-52-1-2) and one temperate japonica (Dongjinbyeo) was compared at different plant densities and nitrogen levels under Korean environmental conditions. Although tropical japonicas showed low tillering habit and large panicles, they had similar leaf area index and dry weight at heading stage to Dongjinbyeo of the high tillering type indicating that there was not much difference between tropical and temperate japonica in terms of biomass production. The highest milled rice yield of 6.15 t/ha was obtained from Dongjinbyeo at a high nitrogen level with less planting density (220 kg N/ha and 30
15 cm). However, those of the two tropical japonicas were 5.36 t/ha at the condition of 165 kg N/ha and 30 x 10 cm planting density and 5.06 t/ha at the condition of 165kgN/ha and 15 x 15 cm planting density, respectively. Ripened grain of tropical japonicas ranged from 65 to 87%, while that Dongjinbyeo ranged from 82 to 97% under Korean conditions.
Vetch Effects for the Low-input No-till Direct-Seeding Rice-Vetch Cropping System
Cho, Young Son ; Choe, Zhin Ryong ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 221~224
A field experiment was carried out to observe the weed control effects of vetch and to evaluate vetch characteristics on clay loam soil in no-till direct-sown rice-vetch cropping systems. The effects of weed control, forage productivity, and N content of vetch plants were investigated. With the progress of plant growth, density of Chinese milk vetch (Astragalus sinicus L.) gradually decreased, but densities of foxtail and other weeds decreased steeply due to the depression by the over-shaded vetch canopy in a no-till direct-sown rice-vetch cropping paddy field. The vetch density in tillage systems was lower than in notillage cropping systems. Lower vetch density occurred with an increase in foxtail density and other weeds. Weed control effect increased by the progress of vetch growth, which indicated that the vetch canopy over-shaded the weeds. Vetch straw was degraded rapidly submergence after with water at the time of wet sowing of rice. Early harvesting of vetch seed resulted in lower seed germination. To acquire enough seedlings without re-sowing, the harvesting of seed should be delayed at least 28 days after the flowering stage in order to ensure the vetch population is sustainable in a no-till direct-sown rice-vetch cropping system. In order to improve the survival of vetch plants, vetch seeds should germinate from the heading .stage to before the full-ripening stage of rice plants. To enhance the percent of over-wintering survival, vetch seeds should germinate no later than the end of October in southern Korea. The dry weight of vetch plants increased with the progress of vetch growth until the flowering stage but N content decreased for 30 days from before the flowering stage (2.9%) until the ripening stage (1.8%). We concluded that Chinese milk vetch could have an effect on weed control before the flowering stage, sustainability without re-sowing of seed annually, and effective green manure for rice pre-crop in no-till direct-sown rice-vetch relay cropping systems.
Seedling Stand Influenced by Water Management after Seeding and Seed Soaking with Plant Growth Regulators in Direct Wet Seeding Rice
Back, Nam-Hyun ; Kim, Sang-Su ; Kang, Si-Yong ; Choi, Min-Gyu ; Shin, Hyun-Tak ; Kwon, Tae-Oh ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 225~229
Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA
) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.
Effects of Urease Inhibitor, Nitrification Inhibitor, and Slow-release Fertilizer on Nitrogen Fertilizer Loss in Direct-Seeding Rice
Lee, Jae-Hong ; Lee, Ho-Jin ; Lee, Byun-Woo ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 230~235
To study the effects of an urease inhibitor, N-(n-butyl)-thiophosphoric triamide (NBPT), and a nitrification inhibitor, dicyandiamide (DCD), on nitrogen losses and nitrogen use efficiency, urea fertilizer with or without inhibitors and slowrelease fertilizer (synthetic thermoplastic resins coated urea) were applied to direct-seeded flooded rice fields in 1998. In the urea and the urea+DCD treatments, NH
-N concentrations reached 50 mg N L
after application. Urea+NBPT and urea+ NBPT+DCD treatments maintained NH
-N concentrations below 10 mg N L
in the floodwater, while the slow-release fertilizer application maintained the lowest concentration of NH
-N in floodwater. The ammonia losses of urea+NBPT and urea+NBPT+DCD treatments were lower than those of urea and urea+DCD treatments during the 30 days after fertilizer application. It was found that N loss due to ammonia volatilization was minimized in the treatments of NBPT with urea and the slow-release fertilizer. The volatile loss of urea+DCD treatment was not significantly different from that of urea surface application. It was found that NBPT delayed urea hydrolysis and then decreased losses due to ammonia volatilization. DCD, a nitrification inhibitor, had no significant effect on ammonia loss under flooded conditions. The slow-release fertilizer application reduced ammonia volatilization loss most effectively. As N0
-N concentrations in the soil water indicated that leaching losses of N were negligible, DCD was not effective in inhibiting nitrification in the flooded soil. The amount of N in plants was especially low in the slow-release fertilizer treatment during the early growth stage for 15 days after fertilization. The amount of N in the rice plants, however, was higher in the slow-release fertilizer treatment than in other treatments at harvest. Grain yields in the treatments of slow-release fertilizer, urea+NBPT+ DCD and urea+NBPT were significantly higher than those in the treatments of urea and urea+DCD. NBPT treatment with urea and the slow-release fertilizer application were effective in both reducing nitrogen losses and increasing grain yield by improving N use efficiency in direct-seeded flooded rice field.field.
Effect of Early Seeding on Seedling Establishment and Yield in Direct Dry Seeding Rice at Honam Plain Area of Korea
Kim, Sang-Su ; Back, Nam-Hyun ; Chot, Min-Gyu ; Choi, Weon-Young ; Park, Hong-Kyu ; Kim, Bo-Kyeong ; Shin, Hyun-Tak ; Cho, Soo-Yeon ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 236~242
To examine the seedling stand and growth as affected by early seeding dates of dry direct seeded rice in the Honam plain area of Korea, Dongjinbyeo was seeded at six seeding dates from early March to late April in rice fields of silty loam soil(Jeonbuk series) at the National Honam Agricultural Experiment Station (NHAES) for two years, 1996 and 1998. Seedling stand decreased slightly. with an early seeding date, but it produced more than the optimum seedling number except for the seeding of 25 March in 1996. Days to emergence was significantly longer, as seeding date was earlier, and days to emergence by early seeding was shortened only by 8 days because the mean air temperature was lower in 1996 than average, while in 1998, the reduction effect was nine to twenty five days because the mean air temperature was higher than average. In early seeding, various weeds occurred at the emergence date of rice and dominant weeds were Alopecurus aequailis, Ludwigia prostata and Rorippa islandica. NH
-N content in the soil at the 5th leaf stage and maximum tillering stage were lower, as the seeding date was earlier when nitrogen was split applied as basal and top dressed in 1996, while it was not significantly different among seeding dates when nitrogen was intensively applied as a top dressing in 1998. Tiller number at the maximum tillering stage and panicle number/m
were more, as seeding date was earlier in 1996, while it was not different in 1998. Filled grain rate and 1,000 grain weight was not different among the seeding dates. Milled rice yield was significantly decreased in the seeding before the middle of March, but in the seeding after late March, it was not varied when compared with the normal seeding date in 1996, while in 1998, there was no difference among seeding dates. From the above results, in consideration of seedling stand, weed occurance, rice growth and milled rice yield, the critical optimum early seeding time in the southern plain area may lie in early April. But it was suggested that when soil moisture is proper for seeding practices, seeding amount is increased and nitrogen is applied after plumule emergence of rice, milled rice yield may not be reduced in the seeding of middle or late March, compared with the seeding in April.l.
RFLPs of Mitochondrial DNA in Korean Wild Soybeans
Ouk-Kyu, Han ; Jun, Abe ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 243~247
Mitochondrial DNA restriction fragment length polymorphisms are convenient markers for identifying cytoplasmic variation among plants. We have collected 212 wild soybeans (Glycine soja Sieb. et Zucc) from all over Korea, and classified mitochondrial genome types based on hybridization patterns in DNA gel-blot analyses using two mitochondrial DNA clones, cox2 and atp6, as probes. Korean wild soybean was classified with eight-mtDNA types, and some of the mtDNAs showed geographical clines among the regions. The diversity index of the mtDNA was much higher in the western and southern regions than in the eastern and northern regions of Korea, respectively. Dissemination and distributive characteristics of wild soybeans in Korea were discussed.
Effects of Growth Retardants on Lodging-related Traits in Direct Seeded Rice on Flooded Paddy Surface
Ju, Young-Cheoul ; Park, Jung-Soo ; Han, Sang-Wook ; Park, Kyeong-Yeol ; Rho, Young-Deok ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 248~252
This study examined the effects of growth retardants and midsummer drainage on lodging-related characters in direct seeding rice culture on flooded paddy surfaces. Treatments included in this study were continuous flooding, two time midsummer drainages (TTD), and inabenfide or trinexapac-ethyl application after TTD. Culm length was reduced most by 11.4cm in trinexapac-ethyl treatment after TTD, followed by 4.1cm in inabenfide treatment after TTD compared to TTD treatment. A significant reduction in culm length occurred at the 3rd internode in inabenfide treatment applied at 40 days before heading (DBH), while trinexapac-ethyl application at 8 DBH reduced the 3rd>2nd>1st internode. The culm diameter of the 4th internode was increased by the application of trinexapac-ethyl following TTD compared to TTD treatment. Thickness of culm wall was significantly increased by trinexapac-ethyl but not by inabenfide applications. Lodging index was the highest in continuous flooding and the lowest in trinexapac-ethyl treatment after TTD. Subsequently, field lodging did not occur in plots treated by trinexapac-ethyl. Rice plants subjected to midsummer drainage or growth retardants showed higher ripened grain ratio and 1000-grain weight, resulting in higher rice yield. These results indicate that trinexapac-ethyl, which can be applied at the relatively later growth stage after proper judgement of lodging occurrence, could be a useful tool for reducing lodging in direct seeding rice culture on flooded paddy fields.
Detection of Soybean Mosaic Virus Using RT-PCR
Kim, Yul-Ho ; Kim, Ok-Sun ; Lee, Bong-Choon ; Roh, Jae-Hwan ; Kim, Myoung-Ki ; Im, Dae-Joon ; Hur, Il-Bong ; Lee, Sang-Chul ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 253~255
Reverse transcription and polymerase chain reaction (RT-PCR) assay was used to detect SMV strains. A pair of oligonucleotide primers were designed to include the cylindrical inclusion (CI) coding region between 4,176 to 5,560 nt. Amplification from the total RNA extracted from infected plants with SMV yielded a 1,385 bp DNA fragment. RT-PCR was shown to be
times more sensitive than the ELISA assay and it could detect a virus in
dilution. Restriction enzyme analysis of RT- PCR products using EcoR I showed that SMV isolates were classified into six groups according to the patterns of restriction fragments.
Genetic Diversity of Soybean Landraces in Korea
Han, Ouk-Kyu ; Abe, Jun ; Shimamoto, Yoshiya ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 256~262
To evaluate the genetic diversity and structure of the South Korean soybean population, 233 landraces collected in various regions of the country were surveyed for 15 allozyme loci and one protein locus. The South Korean population was fixed or nearly fixed at seven of the 16 loci tested. The number of alleles per locus was 2.06 and Nei’s gene diversity was 0.194. These values were lower than the values for the same 16 loci previously reported for the Japanese and Chinese populations. The differences among eight regional groups were not so marked, with only 7.2% of the total variation arising from regional differentiation. Three southern regional groups (Chollabuk-do, Chollanam-do and Kyong-sangnam-do) exhibited a relatively high variability because of frequent occurrence of alleles characteristic of the Japanese population. A marked difference was found in allelic frequencies at the Dial locus between large-seeded landraces and small-seeded ones, suggesting that the latter, which are used mainly for bean sprouts, had been established independently of the former, which are used mostly for soy sauce and cooking with rice. Not only the region but also the usage as food materials should therefore be taken into consideration in designing an efficient collection and preservation method for the Korean soybean landraces.
Optimum Conditions for Tobacco Seed Priming by PEG 6000
Tai-Gi, Min ; Byung-Moon, Seo ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 263~266
Tobacco (Nicotiana tabacum L. ‘KF109’) seeds were primed in polyethylene glycol 6000 (PEG 6000) solutions to determine a) what osmotic potential of the solution would be optimal for priming, i.e., critical potential level for preventing germination, and b) what temperature and duration would be the most effective in priming. The germination was completely prevented below -0.8 MPa of PEG 6000, that indicates a optimum water potential for seed priming. Seeds were primed for 0, 1, 2, 3, 5, 10 and 15 days at 15, 20 and
, respectively, under the-0.8 MPa PEG 6000 solution to find out the most effective temperature and duration for priming. The effectiveness of priming, particularly in germination speed, was observed more distinctly when the primed seeds were germinated at 15
than 2 5
. The greatest reduction of the time to 50% germination (T/sob 50/) was when the seeds were primed at
. The reduction rate of the
was rapid when primed from 1 day to 8 days and then slowed down in the seeds primed for longer than 8 days. The time from 10 to 90% germination (
increased in the primed seeds for longer than 8 days which showed the reversed effect of synchronous germination. However,
was reduced continuously in the seeds even primed over 8 days. Thus, the optimum condition for tobacco seeds priming with PEG 6000 solution was -0.8 MPa in osmotic potential of the solution at
for 8 days.ays.
Sugars, Soluble Solids, and Flavor of Sweet, Super Sweet, and Waxy Corns during Grain Filling
Lee, Suk-Soon ; Yun, Sang-Hee ; Kim, Jae-Hyeun ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 267~272
In order to determine the optimum harvest time of vegetable corns, the changes in sugars, soluble solids, and flavor of kernels of sweet (cv. ‘Golden Cross Bantam 70’), super sweet (cv. ‘Cocktail E-51’), and waxy corns (cv. ‘Chalok 2’) were observed at different ripening stages. Sucrose was a major sugar in the sweet and super sweet corns and the content increased from 15 to 21 and 27 days after silking (DAS), respectively and then decreased. Glucose and fructose contents of sweet and super sweet corns tended to decrease with kernel maturity. Total sugar content of the sweet corn analyzed by the anthrone method increased rapidly from 15 to 21 DAS, while that of the super sweet and the waxy corns increased slowly up to 24 and 26 DAS, respectively and decreased thereafter. The content of soluble solids in sweet corn was much higher than that of super sweet corn. Starch content of the sweet corn increased slowly from 15 to 33 DAS, while that of the super sweet corn increased a little rapidly from 15 to 21 DAS and then leveled off to 33 DAS. Starch content of the waxy corn increased continuously from 21 to 38 DAS. There was a positive correlation between the sum of individual sugars (sucrose, glucose, and fructose) and soluble solids in both sweet and super sweet corns, while the content of soluble solids was not related to the sum of individual sugars or total sugars. The flavor rate of sweet and super sweet corns maintained high between 21 and 27 DAS and that of waxy corn decreased from 24 to 33 DAS. The optimum harvest time for sweet, super sweet, and waxy corns was thought to be 21 to 24 DAS considering sugar and starch contents, flavor, and marketing.
Changes in Metabolites and Embryo Growth during Seeds Priming in Tobacco
Min, Tai-Gi ; Seou, Byung-Moon ; Lee, Suk-Soon ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 273~276
Some metabolites and embryo growth of primed tobacco (Nicotiana tabacum L. cv. ‘KFI09’) seeds were observed during priming. The seeds were primed at 15 and
for 1, 2, 3, 5, 10 and 15 days in a -0.8 MPa polyethylene glycol 6000 (PEG) solution. The time to 50% seed germination (T
) was greatly reduced when the seeds were primed at
when compared with 15
-amylase activity and sugars and amino acid contents in the seeds primed at
greatly increased, while
-amylase activity was similar, and sugar and amino acid contents increased slightly in the seeds primed at 15
. When the seeds were primed at
, growth of the embryo which was enclosed by endosperm was detected, while the endosperm became thinner as the priming duration was extended.d.
Physicochemical Properties of Non-glutinous, Dull, and Glutinous Rice Grain in Segregating Populations of Dull/Glutinous Crosses
Kim, Kwang-Ho ; Kim, Eun-You ; Jeong, Young-Pyeong ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 277~281
Dull grains segregated from F
of the crosses between two dull mutants and a glutinous cultivar were compared with non-glutinous and glutinous segregants for their physicochemical properties. Amylose content of dull rice grain segregated from the dull/glutinous cross showed the intermediate value between glutinous and non-glutinous rice grain, whether it is controlled by the recessive or dominant gene. Alkali digestibility value (ADV) of dull rice grain was lower than that of glutinous or non-glutinous rice. A positive correlation was found between ADV and amylose content of homozygous non-glutinous or dull F
grains, but a negative relationship was observed in glutinous grains. Protein content of dull grain was significantly higher than that of glutinous or non-glutinous grain segregated from the same cross, while those of glutinous and non-glutinous grains were not different. Among gelatinization characteristics, initial pasting temperature and peak viscosity of dull grains were higher than glutinous rice, and were not different with non-glutinous grain. Hot, cool and consistency viscosities of dull grain were intermediate between glutinous and non-glutinous rices. Dull grains showed the highest breakdown viscosity and the lowest setback viscosity among the three endosperm types.
Effects Water Stress on Physiological Traits at Various Growth Stages of Rice
Choi, Weon-Young ; Park, Hong-Kyu ; Kang, Si-Yong ; Kim, Sang-Su ; Choi, Sun-Young ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 282~287
The object of this study was to determine the difference of the time course changes of transpiration, diffusion resistance and photosynthetic rate of rice at several different growth stages subjected to soil moisture stress (SMS) and recovery by irrigation. A japonica rice cultivar 'Dongjinbyeo', was grown under flooded condition in a plastic container filled with silty loam soil. At 5 main growth stages, the container was treated by SMS until initial wilting point (IWP) and then reirrigated. The duration of SMS until IWP were the longest, 13 days for tillering stage, and the shortest, 7 days for panicle initiation and meiosis stage. The transpiration rate rapidly decreased during SMS and the transpiration rate at IWP of the stressed plant showed 10∼20% compared with control, and the transpiration rate of stressed plant at most growth stages also recovered rapidly after irrigation and then reached 100% of control within a week. The shoot photosynthetic rate in all growth stages rapidly decreased by SMS, and the rates at IWP of stressed plants were de-creased nearly to 0%, beside the treatment at tillering stage. The recovery degree of photosynthetic rate by irrigation ranged from 20 to 90%, showed higher at early growth stages of SMS treatment than that of later stages. At all growth stages the leaf diffusion resistance of stressed plants was over 3 times that of the control resulting from a rapid increase at 3 to 5 days after draining for SMS, and showed quick recovery by irrigation within 3 days after drainage. The above physiological parameters changed in close relation with the decrease of the soil matric potential after SMS. These results indicate that at all main growth stages of rice plants the transpiration and photosynthesis reduction by stomatal closure reponded sensitively to the first stage of SMS closely related with decrease of soil water potential, while those recovery pattern and recovered degree by irrigation are little different by growth stage of rice.
Varietal Difference in Water Absorption Characteristics of Milled Rice, and Its Relation to the Other Grain Quality Components
Hae Chune, Choi ; Jeong Hyun, Chi ; Soo Yeon, Cho ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 288~295
Nineteen japonica and Tongil-type rices were selected from seventy nine Korean and Japanese rice cultivars grown in 1989 based on the water uptake behavior of milled rice under the room temperature and boiling conditions. The selected rice cultivars were investigated for water absorbability and some physicochemical characteristics of milled rice, proper water amount for cooking and sensory evaluation of cooked rice. The relationships among the tested grain properties were also examined. The highest varietal variation of water uptake rate was observed at twenty minutes after soaking in water. The maximum water uptake of milled rices at room temperature occurred mostly at about eighty minutes after soaking in water. Newly harvested rices showed a significantly lower water uptake rate of milled rice at 20 minutes after soaking, a relatively higher maximum water absorption ratio under the room temperature, and the less water uptake and volume expansion of boiled rice compared with the one-year old rice samples. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice ansd the palatability of cooked rice. The water/rice ratio(in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was averaged to 2.63(in v/v basis). The water amount needed for optimum cooking was the lowest in Cheongcheongbyeo (Tongil-type rice) and the highest in Jinbubyeo, and the amount could be estimated with about 70% fittness by the multiple regression formula based on some water uptake characteristics, ADV and amylose content of milled rice as the independent variables. Nineteen rice cultivars were classified into seven groups based on scatter diagram projected by principal component analysis using eight properties related to water uptake and gelatinization of milled rice.
Effect of UV Radiation on Early Growth of Korean Rice Cultivars(Oryza sativa L.)
Choi, Kwan-Sam ; In, Jun-Gyo ; Kang, Si-Yong ; Bae, Chang-Hyu ; Lee, Hyo-Yeon ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 296~301
The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars.
Expressed Sequence Tags of the Wheat-rye Translocation Line Possessing 2BS/2RL
Jang, Cheol-Seong ; Hong, Byung-Hee ; Seo, Yong-Weon ;
Korean Journal of Crop Science, volume 44, issue 3, 1999, Pages 302~307
Hamlet (PI549276) possessing 2RL was obtained by cross between a wheat cultivar ND7532 (Froid/Centurk) and a rye cultivar Chaupon. Chaupon was known to have resistant gene to biotype L of Hessian fly [Mayetiola destructor (Say)] larvae. The wheat-rye translocation line (Coker797*4/Hamlet) was also known to be resistant to biotype L of Hessian fly larvae. We analysed a set of 96 ESTs from the wheat-rye translocation line (2BS/2RL). ESTs were classified by various physiological processings, such as primary metabolism, secondary metabolism, transcription, translation, transport, signal transduction, defense, transposable element, and others. Three sequences encoding thioredoxin peroxidase, 26S rRNA, and rubisco small subunits were homologous to registered genes in rye. Although limited number of clones were used to develop ESTs, these clones and their sequence information may be useful for researchers studying general physiology and molecular biology on the translocation line.