Temperature is a crucial environmental factor for rice cultivation due to the climate change and can influence the rice growth and development. Therefore, the effect of temperature on plant growth characters was examined during the vegetative growth stage. Plants were grown under three different temperatures: 23°C/13°C for 18°C, 26°C/16°C for 21°C and 29°C/19°C for 24°C in the phytotron. The temperature was treated after transplanting and ended in early panicle initiation stage. Heading date of the two varieties were strongly affected by the temperature and were delayed in the 18°C. The plant height in the 18°C was 21 % shorter than the 21°C and 24°C and the tiller and leaf number were increased in the 18°C. All the growth rates of the characters were the slowest in 18°C. The stem dry weight was significantly increased in 18°C. Nitrogen content was increased in the leaves of 18°C whereas available phosphate and potassium contents was found to be increased in the stems of 21°C and 24°C. OsNRT2.1 was overexpressed in the leaves and stems of 18°C and OsNRT2.3a could be expressed in 18°C and 21°C temperatures whereas more expressed in 21°C. OsPT1 and OsPT6 could be expressed in the leaf of 18°C and 24°C but could be expressed more in the stem of 18°C. OsHAK1 and OsHAK5 could be overexpressed in the leaves and stems of 18°C. For hormone, OsCKX2 gene was found to be up regulated in the leaves of 18°C and OsIAA1 gene could expressed more in the stem of 24°C.

본 조사는 일본의 쌀 검사 제도와 품위 등급 규격에 대한 동향을 살펴보고 그에 따른 내용을 파악하여 국내 쌀 산업 발 전 방향에 도움이 될 수 있는 방안을 모색하고자 수행하였다. 1. 농업 경쟁력 강화 프로그램으로 2016년부터는 농산물 규격 검사의 간소화로 최근에는 곡물 검사장에 곡물 판별기를 활용하여 뉘, 맥류, 뉘 이외 곡물 등을 이종 곡립으로 통합하여 5% 이내로 개정하였다. 2. 쌀에 대한 손실 방지를 위해 정미의 포장 표시를 년·월· 일 표시에서 상·중·하순으로 개정하였다. 3. 일본은 매년 생산된 현미 품위 생산량과 등급 비율을 공개 하고 있으며, 1등급 쌀을 대상으로 식미 랭킹을 선정하고 있다.

베트남 메콩 델타 지역은 베트남에서도 쌀 생산이 활발히 이루어지는 지역으로 꼽히고 있으나 기후온난화에 따른 고온 현상 증가로 쌀생산량 감소의 우려가 증대되고 있다. 이에 고온에 따른 벼 피해발생 현황 및 대응 기술에 대한 정보를 제공하고자 한다. 베트남의 평균기온은 2060년 까지 약 2.7oC 증가, 35oC 이상의 폭염은 2030년까지 2달 이상 길어질 것으로 예측되고 있으며 기온상승에 따라 기온이 높은 작기의 벼 생산량이 감소되고 있다. 벼 개화기 온도가 33oC 이상으로 높을 시, 화분의 감수분열에 영향을 미쳐 화분의 활력이 저하되며 수술에서 약의 개열이 감소되어 화분의 방출이 감소될 뿐만 아니라 화분이 암술의 주두에 부착하여 발아 시 발아율을 낮추어 불임 발생이 증가하게 된다. 베트남의 벼 연구소는 고온에 대비하여 베트남 벼 생산의 안정화를 위해서 개화기에 내열성을 가지는 품종 육성 뿐만 아니라 이른 아침에 개화할 수 있는 품종을 육성하고 있다. 또한 재배 적인 측면에서 고온 피해를 줄일 수 있도록 벼 재배시기를 조절하여 기존 3기작에서 고온피해가 큰 시기의 재배를 제외한 2기작으로 재배하는 반면 파종 및 이앙시기를 조절하여 벼의 생육량을 충분히 확보하여 2기작에 따른 수량감소를 최소화하는 연구가 필요하다. 더불어 벼를 재배하지 못하는 무더운 계절에는 농업인의 소득보존을 위해 논을 이용한 물고기 양식 기술 도입하는 것도 필요하며, 시비 방법 등의 개선을 통한 벼 생육량 조절, 물관리 기술 개발을 통한 포장 미세기상변화 등의 연구가 필요할 것으로 판단된다.

Since Japonica rice is recognized as the premium rice in some subtropical region such as Philippines, the development of new cultivar adaptable in subtropical region has been conducting. However typical Japonica rice show earlier flowering in subtropical region due to the short day length and high temperature conditions. In such a condition, it is difficult to secure enough yields. Therefore it is need that selection of Japonica cultivar showing suitable heading characters in subtropical region. Here we try to check the basic vegetative phase and heading sensitivity on temperature condition using 37 kinds of Korean cultivars. BVP is between 14 to 39 days and 37% of cultivar had basic vegetative phase between 26 to 30 days. When temperature became lower on sensitive and reproductive stage, heading was more delayed. However the 24oC condition showed the greatest impact on heading delay among temperature condition. Among cultivars, 56% of cultivars have basic vegetative phase over 25days.We checked temperature effect on heading especially sensitivity stage in those materials. Joun, Manho, Joan and Cheonga showed stable heading date under different temperature conditions. With this data, we suggest that Joun, Manho, Joan and Cheonga could be a good cultivar in subtropical region in heading characters.

This study was conducted to clarify the effect of high temperature during winter period(autumn sowing) and spring sowing on yield, quality and growth and development in barley. The varieties used for the experiments were heenchalssalbori and keunalbori 1 having a strong spring habit characteristics. In spring sowing treatment, spikelet differentiation was proceeded rapidly and tillering was proceeded slowly compared to the development stage, because the barley sowed at spring is cultivated in high temperature and long day conditions from sowing to spikelet differentiation stage compared with autumn sowing(control). And in high temperature treatment during winter period, like spring sowing, tillering was inhibited compared to the development stage. The number of grain per panicle and the period required to heading stage from spikelet differentiation were reduced largely at spring sowing, because spring sowing treatment was conducted in high temperature and long day condition compared with autumn sowing and high temperature treatment during the period from spikelet differentiation to heading stage. Meanwhile in spring sowing treatment, average temperature during ripening stage was higher than the autumn sowing and high temperature during winter, because heading stage was so late. After all, starch, amylose content and grain weight were reduced while protein content was relatively increased in spring sowing treatment due to difference of average temperature of ripening stage. These changes affected the decrease of viscosity of peak, trough, breakdown and the increase of setback viscosity

We investigated the changes in the physicochemical properties of wheat grains during ripening stage to determine the effect of the rise in average temperature on that of wheat grains. The treated average temperatures were 18.3°C(control), 19.9°C(1.6°C increase), 21.5°C(3.2°C increase) in artificial climate room from heading time to harvest. Results showed that the ripening period from heading to maturity tended to be shorter during higher temperature treatment condition. The 1,000-grain weight, grain width, number of florets per spike, and number of grains per spike decreased as the ripening period was shortened. Gelatinization properties were affected by high temperature due to the reduction of starch and amylose contents. As the grain filling period was shortened by high temperature treatments, the crude protein content increased. As the grain filling period was shortened by 6 days, the starch and amylose contents decreased by 10.8% and 5.4%, respectively. However, the crude protein content increased by 1.7% in such a condition. Starch content showed positive correlations between amylose and breakdown. Meanwhile, it showed negative correlations between electric conductivity of leaching water from seeds, crude protein content, peak viscosity, trough viscosity, final viscosity, and setback.

We investigate the change of leaf chlorophyll content according to iron content in brown rice when cultivated on the iron limited solid MS medium. By cultivating wild-type and transgenic brown rice in a solid MS medium, we confirmed that iron deficiency chlorosis did not occur in MS media which were contained over 20% of iron content compared to normal MS condition. After selecting twenty kinds of Korean rice varieties, those brown rice were cultivated in solid MS media which were contained from 0 to 15% of iron content compared to normal MS condition then the leaf chlorophyll content was measured. The leaf chlorophyll content was changed according to iron content in brown rice when cultivated in solid MS medium which was contained 0 and 5% of iron content,. There was a strong correlation between iron content in brown rice and leaf chlorophyll content cultivated in solid MS medium with 5% of Fe content. Therefore we expect that analysis of leaf chlorophyll content after cultivated on MS medium with 5% iron content compared to normal MS media condition will be more simple and effective method to screening high iron content brown rice without measurement of iron content.

This experiment was conducted to clarify the effect of the high temperature on physicochemical properties of barley kernels during ripening stage. High temperature treatment was lasted from each 10, 17 and 24 days after heading(DAH) until the harvest time at 21oC, 24oC, 27oC in artificial climate room. The results showed that ripening period from heading to maturity was tend to be shorter at higher temperature treatment condition and at longer duration treatment condition. and 1000-grain weight was decreased as the ripening period shortened. Furthermore, gelatinization properties was changed by high temperature due to the reduction of starch and amylose contents. As the shortening of grain filling period by a high temperature treatment, the protein content was increased. In the 10 DAH at 27oC treatment, the grain filling period was shortened by 9 days. The starch contents was reduced by 5.7 %, and the protein content was increased by 5.6 % in a such condition. Protein contents was showed negative correlations with amylose, starch contents and gelatinization properties, respectively. Starch contents, however, showed positive correlations with amlyose content and gelatinization properties.

We investigated the change of growth characters by over-expressing OsPT6 (OsPT6-OX) under phosphorus (Pi) deficient condition in rice. In analyzing the change of growth rate according to Pitreatment for two weeks, shoot growth rate of OsPT6-OX was increased in Pi deficient condition than in Pi sufficient condition. Therefore, the chlorophyll content of leaf in OsPT6-OXs did not increase even decreased in the youngest leaf. However growth rate of wild type plant in Pi deficient condition showed significant reduction with increment of chlorophyll content. In analyzing agronomic characters, the tiller number of OsPT6-OX less decreased than those of wild type plant in Pi deficient condition. Panicle number and ripening rate of wild type plant were changed according to Pi treatment. However those of OsPT6-OX did not change in such conditions. Resulting of changes in agronomic characters, yield of wild type plant decreased about 10 % in Pi deficient condition. That of OsPT6-OX did not show significant difference in Pi deficient condition. The results obtained this study demonstrated that over-expression of OsPT6 could increase phosphorus deficient stress resistance in rice.

Limonium tetragonum is a halophyte grown naturally in the coastal region in South Korea. This study was conducted to investigate the effects of salt concentrations on seed germination, seedling growth, and antioxidant capacity of L. tetragonum. Seeds were collected from naturally grown plants of L. tetragonum and those at full maturity were used in this experiment. All experiments were performed at 0%, 0.5%, 1.0%, or 2.0% of salt concentrations. Seed germination rate was highest as 86% at 20℃ and followed as higher in order of 25℃, 30℃ and 15℃. The germination rate was about 80% at 0% or 0.5% of salt concentration, but it was very low at the salt concentrations higher than 1%. Growth of L. tetragonum seedlings showed no difference in Hoagland solution containing NaCl in the range of 0% to 1.0% and seedlings survived at 2.0% of NaCl concentration. As the salt concentration increased, the content of Na+ in the shoot increased, but that of K+, Ca++, or Mg++ decreased. The antioxidant activity and the content of total polyphenol and total flavonoid in the shoot were similar at 0% and 0.5% of NaCl and were highest at 2.0% of NaCl concentration. In conclusion, performance of seed germination and plant growth of L. tetragonum was highest at 0% and 0.5% of NaCl concentration, and showed no difference in antioxidant activity, total polyphenol contents, and total flavonoid contents at the same salt concentrations.

This experiment was conducted to evaluate the effects of high temperature on the stem, leaf and grain of barley during the ripening period and to provide information for the development of high-temperature cultivation techniques and adaptive varieties. We used an artificial climate control facility, to provide a temperature 3℃ higher than the normal average temperature during the ripening stage. Although the maximum rate of starch synthesis was increased at high temperature by approximately 11%, the starch content was decreased, because the period of starch synthesis ended 4 days earlier. As in the case of starch synthesis, the expression of genes related to starch synthesis was increased at the early ripening stage in the high temperature treatment, however, the duration of expression tended to decrease rapidly. Furthermore, the partitioning rate of assimilation products in the panicle increased to a greater extent in the high temperature treatment than in the control. In contrast, for the stem and leaf, the partitioning rate of assimilation products decreased more rapidly in the high temperature treatment than in the control. On the basis of these results, it can be considered that the translocation rate of assimilation products increased to a greater extent in the high temperature treatment than in the control at the early ripening stage. These results indicate that the decrease in grain weight at high temperature during the ripening stage is attributable to an increase in the speed of starch synthesis at high temperature, but the increase in ripening speed does not compensate for the shortening of the ripening period. Finally to develop varieties and cultivation techniques suited to high temperature, we need to focus on physiological characteristics related to the duration of starch synthesis.

The increase in the frequency of occurrence of abnormal weather could include severe rainfall, which could cause rice submergence during the ripening stage. This experiment was conducted to clarify the effects of submergence during the ripening period on yield and quality of rice. The flooding treatment was conducted at 7 and 14 days after heading. Flooding conditions were created with two conditions, flag leaf exposed and overhead flooding, and each condition was divided into two conditions according to water quality—clear and muddy. Although the yield decrease was more severe at 7 days after heading because of the decrease in the ripening ratio, the head rice ratio was more affected at 14 days after heading because of the increase in the chalky kernel ratio. The maximum quantum yield (Fv/Fm), which indicates the photosynthetic efficiency, did not differ before and after the flooding treatment until flooding continued for 4 days. In addition, stem elongation occurred because of flooding as an avoidance mechanism in japonica rice. This phenomenon was expected to decrease the supply of assimilation products to the spikelet (sink). Overall, it was suggested that additional experiments should be conducted examining the change in the starch synthesis mechanism and transfer of assimilate products resulting from submergence, for development of cultivation techniques corresponding to submergence and breeding of varieties with submergence tolerance characteristics.

To fit the market demands for functional rice such as black and red color rice, ‘Sugary’a high free sugar content line was backcrossed to the black rice ‘Milyang152. The pedigree method was adapted in selection and generation advance. A high polyphenol content line, YR19646-3-2-1-1-2-2 showing red pericarp was selected and designed as ‘Milyang234’ followed by variety name ‘Geonganghongmi’ in 2010. Heading date of ‘Geonganghongmi’ was Aug. 19, medium-late maturing cultivar. ‘Geonganghongmi’ showed resistance to leaf blast and rice stripe virus while susceptible to major diseases and insects. The total polyphenol content of ‘Geonganghongmi’ was high as much as 24.2mg/g compare to that of 4.9mg/g of ‘Nampyeongbyeo’ and 17.2mg/g of a red pericarp rice ‘Jeogjinju’ at 70% ethanol extraction conditions. In local adaptability tests, yield of ‘Geonganghongmi’ was 4.5MT/ha about 86% of ‘Nampyeongbyeo’ and 102% of ‘Jeogjinju’, respectively. ‘Geonganghongmi’ is suitable for southern and middle plain area of Korea.

Heading time is important element for yield and quality in crops. Among day length and temperature which influence on heading, temperature effect has not been investigated well. To investigate temperature effect on heading, heading date and plant growth characters were checked under the low and high temperature conditions in short day length. Analyzing heading date of six Korean varieties under the high and low temperature condition, heading date of varieties were delayed under low temperature. In the low temperature condition, dry weight and area of leaf were reduced. Varieties showing more delay of heading under low temperature also showed more reduction in leaf area. After selecting three varieties showing significant difference in leaf growth and heading date under different temperature conditions, nutrient contents of plant were analyzed. Nitrogen content was reduced in leaf and shoot under the low temperature condition. OsNRT2.3, nitrate transporter, was significantly down regulated in varieties showing more heading delay. Available phosphate content was decreased in leaf, but increased in shoot due to reduction of phosphate mobility. OsPT1, phosphate transporter regulating phosphate uptake, was more down regulated in varieties showing more heading delay. OsPT6, phosphate transporter regulating phosphate transport in plant, was also significantly down regulated in those varieties. With these data, we expected that active nitrogen and available phosphate uptake and transport in plant would increase leaf growth then might reduce heading delay under the low temperature condition.

Even though phosphorus (P) is essential element for plant growth and development, it is not enough for crop production in soil. To breed more P deficient tolerance rice, screening and selection in rice population is needed. We tried to develop more simple and rough screening method for breeding of P deficient tolerance rice. In P deficient condition, tiller number was dramatically decreased among yield components in rice. Though this result, we confirmed tiller number could be the best marker in screening of P deficient tolerance rice. 480 rice genetic resources were cultivated in rice bed tray filled with P deficient soil for four weeks and each dry weight was measured. Among them, the 55 kinds of genetic resource were selected then cultivated in paddy field with 3 fertilizer conditions. Plant dry weight and tiller number in ripening stage were shown significant difference according to P condition. Plant dry weight and tiller number in ripening stage was highly correlated especially in P deficient condition. Furthermore, the tiller number in ripening stage and plant dry weight in rough screening were shown high degree correlation. Though these results, we might expect measuring of plant dry weight after cultivation in rice bed tray filled with P deficient soil could be a simple and effective screening method in selection of P deficient tolerance rice.

Even rice is one of the most important food crops in the world, its micronutrient contents including iron is not enough to solve mineral malnutrition which is a significant public health issue in most developing countries. Iron deficiency is probably the most widespread micronutrient deficiency in humans. Experts estimate that a rice based diet should contain 14.5 ppm iron in endosperm. However, Cesar P et al reported that average iron content in milled rice was 2 ~ 3 ppm, whease it was 10 ~ 11 ppm in brown rice. Fe content of rice is usually measured by inductively plasma spectrometry (ICP). It takes times and could make error while sample processing. To breed high iron contained rice variety, the effective screen method for select high iron contained elite line is essential. To develop more effective method in screening high Fe contained brown rice, we investigate the relation the leaf chlorophyll content with iron content in brown rice. Result of analyzing leaf chlorophyll content of OsNAS3-OX which contain more Fe than wild-type plant after cultivated on Fe limited MS medium, those of OsNAS3-OX was higher than those of wild-type plant in 0 and 20 % Fe contained MS medium. After measured Fe content in twenty kinds of brown rice, we cultivated those in Fe limited MS medium then investigate the relation of leaf chlorophyll content with Fe content of brown rice. In 0 and 5 % Fe contained MS medium, the leaf chlorophyll content was highly related with Fe content of brown rice as 0.66 and 0.79. Though these result, analyze of leaf chlorophyll content cultivated in 5 % Fe content in MS media was effect on screening high Fe contained.

Drought is a one of the most serious abiotic stresses limiting rice production. However, little progress has been made in the genetic analysis of drought tolerance, because it is a complex trait controlled by a number of genes and affected by various environmental factors. The most efficient method for drought tolerance breeding is using drought tolerance genetic resources. We used a doubled-haploid (DH) population consist of 101 lines derived from a cross the drought tolerant cultivar ‘Samgang’ and the drought sensitive cultivar ‘Nagdong’ for QTL analysis. Drought stress was treated by withholding water for 6 weeks, and then rewatered for 7 days. After rewatering visual phenotype was observed according to the standard evaluation system for rice, IRRI. Drought sensitive parent ‘Nagdong’ was almost died, while tolerant parent ‘Samgang’ showed slightly leaf tip dring phenotype. The qdr11 detected on chromosome 11 with flanking markers RM26755-RM287 and accounted for 19% phenotype variation with a LOD score of 3.7.

The global rice reduction due to drought averages 18 Mt, especially, 23 Mha of rice fields in Asia are drought-prone. However, rice breeding programs focusing on drought resistance have made little progress to date. Because proper screening approaches with large scale were not developed to evaluate the drought tolerant degree. In here, we have developed of leaf water loss rate with plastic ware in dark conditions for large screening. Through this bioassay system, we examined drought phenotype degrees of 650 rice varieties. To validate whether this optimized bioassay system is corelated with drought phenotype, we chose 14 varieties having the lowest or highest of the water loss rate. We observed the visual drought phenotype and agricultural traits in green house and field conditions. Apo and Samgang having the lowest of leaf water loss rate showed drought tolerance phenotype, whereas Yeolbaeg and Milyang254 having the highest of leaf water loss rate showed drought sensitive phenotype. Apo displayed proper root length trait and Samgang showed good root dry trait in the greenhouse conditions. These results suggest that a simple screening procedure with water lose rate of leaves is effective to perform large scale screening for drought phenotype in rice.

Green rice leafhopper(GRH), Nephotettix cincticeps Uhier, is one of the major insect pests of rice (Oryza sativa L.) in the temperate growing region of East Asia. GRH sucks sap from both xylem and phoem of susceptible rice varieties, and increased GRH populations cause sooty mold disease on the ears of rice after heading stage. In addition to direct plant destruction, GRH also causes damage to rice plants by transmitting rice dwarf viruses causing rice dwarf viruses disease which could decrease the yield of rice. Development of GRH resistant rice varieties for reducing yield loss is an important objective in current breeding programs. In this study, we developed three SSR markers(RM18166, RM516, RM18171) and one Indel marker(Indel15040) which could select Grh1-resistant varieties using population derived from cross lines between Grh1-resistant variety ‘Singwang’ which contains Grh1 gene and susceptible variety ‘Ilpum’. PCR products of RM18166 which was one of the developed markers were easily detected in agarose gel. These markers will be useful for development of the Grh1-resistant varieties through marker-assisted selection(MAS) without bio-examination in rice breeding