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.

본 연구에서는 평균온도 상승에 따른 출수기변화, 수량구성 요소 및 수량, 출수기건물중 및 식물체 질소함량 변화를 평가 한 결과는 다음과 같았다. 1. 생육기 평균온도 1oC 상승 시 밀의 출수기는 약 2.8일 단축된 것으로 판단되었다. 2. 평균온도 상승 시 수량구성요소와 수량이 악화되었는데, 주로 면적당수수 감소에 의해 면적당립수와 수량이 감소한 것으로 판단되었다. 3. 1수립수는 11월 7일 파종 시 고온조건에서 감소하였으나 11월 17일 파종 시 고온조건에서 감소하지 않았다. 4. 천립중은 출수 후 30일간 평균온도 1oC 당 약 2.1g씩 감소하였다. 5. 평균온도 상승 시 출수기 건물중은 감소하지 않았으나, 출수기 면적당경수는 감소한 것으로 판단되었다. 6. 고온처리 시 식물체 질소흡수량이 감소하여 면적당립수가 감소한 것으로 판단되었다.

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.

‘Palbangmi’ is a super high-yield rice cultivar bred by interspecies cross between Tongil type and Africa rice. But, ‘Palbangmi’ has a problem in grain maturation which results in rice yield decreases. Because ‘Palbangmi’ is Tongil and Africa rice interspecies-crossed cultivar, it would be predicted to require higher temperature for grain maturation than japonica rice. Therefore, ‘Palbangmi’ would be required to determine Late Marginal Heading Date (LMHD) for normal maturation. In this study, experiment of transplanting date was carried out to determine LMHD of ‘Palbangmi’ in Suwon and Iksan for 3 years. When daily mean temperature was below 23oC, grain filling ratio (%) increased about 8% for each 1oC. On the other hands, grain filling ratio (%) didn't increase when the daily mean temperature was above 23oC. Therefore, it is determined that 23oC is adequate for minimum threshold temperature for grain maturation. The LMHD of ‘Palbangmi’ was determined from calculated heading dates for each year which could satisfy threshold temperature for 40 days after heading during last 15 years. As a results, LMHD was earlier than August 1 in 16 regions where it is inadequate for ‘Palbangmi’. Continually, LMHD was August 1 ~ August 5 in 13 regions, August 6 ~ August 10 in 14 regions and August 11 ~ August 15 in 21 regions. Finally, LMHD was later than August 15 in 14 regions. Considering that heading date of ‘Palbangmi’ is August 13 as mid maturing ecotype, it is suggested that earlier transplanting required for normal maturing in almost areas except south plain area and some areas of central plain area.

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.

This study was conducted, using 10 high-quality rice varieties, at 24 experimental sites in 2013 and 2014 to analyze the comparative relationship among head rice yield (HRY), its attributes and sub-attributes. In the data set pooled across sites, years and varieties, where regional and varietal variations were combined, HRY was associated with milled rice yield (MRY) more closely than percentage of head rice (PHR) although both MRY and HRY demonstrated significant relationship with HRY. In the PHR higher than 80%, compared to 80% or less, fitness of the regression between PHR and HRY decreased. MRY and PHR, the two attributes of HRY, were not significantly associated with each other. Regional variation of HRY was associated only with MRY while varietal variation of HRY was related to both MRY and PHR. HRY and MRY showed regional variation greater than varietal variation meanwhile PHR demonstrated regional and varietal variations in a similar range. In the data set pooled across sites, years and varieties, MRY demonstrated relationship with spikelets per square meter (SPIK) in a higher significance than percentage of grain filling (PGF) and 1000-brown rice weight (TBRW). Both regional and varietal variations of MRY showed significant relationship only with SPIK, neitherwith PGF nor TBRW. It is concluded that regional variation of HRY was affected by MRY, varietal variation by both MRY and PHR, and region-variety combined variation mainly by MRY.

우리나라의 수량에 큰 영향을 미치는 요인을 구명하기 위해콩의 주요 생산지인 파주, 안동 및 무안의 3지역에서 2012년도에서 2014년까지 3개년의 설문 및 현지조사의 자료를 분석한 결과는 다음과 같다. 1. 3지역 3년 전체 중회귀분석 결과를 보면 비닐피복을 하면 ha당 488 kg (23%) 증수를 하였고 논재배가 밭재배 대비ha당 520 kg (24%) 증수를 하였으며 추가관수 1회마다(3회까지) ha당 165 kg씩(7%정도) 증수를 보였다. 2. 수량에 큰 영향을 미치는 저수요인은 지역별 기상조건에 따라 달라지지만 무안, 안동 파주 등 3지역을 3년간 조사한 결과를 대상으로 분석하면 콩의 수량 감수 주요인은 6월과9월의 토양수분 부족이었다.

최고품질 벼 칠보의 적정 수확시기를 구명하고자 농업환경이 서로 다른 밀양, 사천, 함양, 상주, 울진 등 5개 지역에서벼를 재배한 후 각 지역별 최적 수확시기를 검토한 결과는 다음과 같다. 1. 기후대에 따라 출수기에서 출수 후 60일까지의 평균기온은 사천이 가장 높았고, 상주가 가장 낮았다. 상주는 평균기온의 저하정도가 다른 지역에 비해 컸으며 울진은 등숙기 평균기온은 낮았지만 온도저하 정도는 가장 적었다. 2. 지역별로 최고수량을 나타내는 수확시기는 지역간의 차이가 있었는데, 백미수량은 밀양과 함양이 60일, 울진과 상주는 55일, 사천은 45일이었고, 완전미 수량은 상주, 사천, 함양은 60일, 밀양, 울진이 50일로 대체로 출수후 50 ~ 60일 사이었다. 이를 적산온도로 환산할 경우 밀양, 함양은 1,200oC, 상주는 1,050oC, 사천, 울진은 1,100oC 부근이었다. 3. 각 지역별로 최고수량을 나타낸 수확시기의 수량을 100으로 표준화하고 나머지 수확시기별 수량을 상대적 비율로 수정하여 적산온도와의 관계를 검토한 결과 칠보의 백미 및 완전미 수량은 적산온도가 1,100oC가 될 때까지 증가하였으며,증가속도는 적산온도 100oC마다 5% 정도였다. 적산온도1,100oC 이후에는 수량증가는 보이지 않았으나 지나친 수확지연은 품질저하가 우려되므로 칠보의 수확적기는 지역에 관계없이 출수 후 적산온도 1,100 ~ 1,200oC 범위로 판단되었다.

총체 사료용 벼의 초기 신장성과 입모 특성을 알아보기 위하여 수원 소재 국립식량과학원 시험포장 조건에서 파종시기를 조절하고, 인공기상연구동 정밀유리실에서 입모기간 중 평균기온을 조절하여 검토한 결과는 다음과 같다. 1. 포장조건에서 총체 사료용 벼 품종 및 계통의 m2당 입모수는 파종시기별로 4월 30일 파종에서 낮은 경향을 보였으나 5월 10일~ 6월 9일 파종에서는 비슷하였고, 품종별로는 녹양에 비해 목우와 수원560에서 많은 경향이었다. 평균기온 18 ~ 24oC 범위의 실내시험에서는 총체 사료용 벼의 입모율은 처리온도간 차이가 없었으며, 모든 온도 처리에서 일반형 품종인 일품보다 낮은 경향을 보였다. 2. 파종 후 30일의 초장은 포장시험에서 파종시기가 늦을수록, 실내시험에서 처리온도가 높을수록 길어졌다. 목우와 수원 560은 녹양보다 입모기간 중 기온 상승에 따른 초장 신장 정도가 컸으며, 특히 목우는 초장 신장 효과가 다른 품종에 비해 고온인 24oC에서 높았다. 3. 파종 후 30일의 건물중은 입모기간 중 평균기온 24oC까지는 기온이 높아질수록 모든 품종에서 증가하였다. 반면 기온이 24oC에서 27oC로 상승했을 때의 건물중은 녹양에서는 비슷하였고 목우와 수원560에서는 감소하였는데 특히, 수원 560의 감소 정도가 컸다. 4. 모든 품종에서 묘 충실도는 입모기간 중 평균기온 24oC까지는 온도가 높을수록 증가하였다. 반면 24oC에서 27oC로 상승한 경우 묘 충실도가 모든 품종에서 감소하였는데, 특히 수원560에서 감소 정도가 컸다. 5. 결과적으로, 담수표면산파에서 초기 신장 촉진과 건전한 입모에 가장 효과적인 입모기간 중의 평균기온은 녹양에서 21oC, 목우와 수원560에서 24oC였으며, 수원560의 경우 24oC 이상의 고온에서는 묘가 연약해졌다.

국내 육성 벼 29품종의 저장기간과 발아온도에 따른 발아율와 발아속도 및 종자활력변화는 다음과 같았다. 1. 국내 육성 벼 29 품종의 발아율은 저장기간 5개월에서15개월까지 차이가 없거나 적었으며 저장기간 30개월에는 발아율이 저하되는 품종이 많아졌다. 2. 발아속도계수는 저장기간 5개월보다 10개월에 약간 증가하였다가 이후 30개월까지 완만하게 감소하였다. 3. 발아온도가 발아율에 미치는 영향은 저장 15개월까지는 처리온도 간 유의한 차이가 없었으나 저장 30개월에는 저온(15oC)에서 크게 낮아졌다. 발아속도계수는 발아율과 달리 발아온도 간 차이가 뚜렷하여 15, 20, 25, 30oC에서 모두 일정한 정도의 차이를 두고 비슷한 경향을 나타내었다. 4. 저장기간 30개월까지 발아율이 98%이상이며 발아속도가 높은 품종은 칠보, 일품, 다산2호, 하이아미, 추청, 일미, 새추청, 백진주이었다. 발아율이 89%이하이며 GCV가 0.25이하인 품종은 영안, 홍진주, 목양, 고아미4호, 고품, 큰눈이었다.

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.

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.

Rural Development Administration has recently developed mid-late maturing rice cultivars with high quality. This study was conducted to select suitable mid-late maturing rice cultivar in major cultivation areas of Gangwon Province among domestic breeding cultivars for 2 years from 2013 to 2014. The average air temperature during the experiment in 2013 and 2014 was higher 0.6~1.1°C in Chuncheon, 1.0~ 1.3°C in Gangreung, and 0.1~0.7°C in Cheolwon than normal year. Precipitation in ripening period was higher 52.5 mm in 2013, but lower 176.4 mm in 2014 than normal year in Chuncheon, lower 103.1 mm in 2013 and higher 42.9 mm in 2014 in Gangreung, lower 225.9~322.7 mm in Cheolwon. Duration of sunshine in ripening period was higher 142 hours in Chuncheon, 108 hours in Gangreung, and 94 hours in Cheolwon than normal year in 2013, higher 20~21 hours in Chuncheon and Gangreung, and 82 hours in Cheolwon than normal year in 2014. Milled rice yield of ‘Samgwangbyeo’ and ‘Daebobyeo’ was 594 kg per 10a, and 578 kg for ‘Jinsumibyeo’ in Chuncheon in plain area. For Gangreung in east coastal area, the yield of ‘Daebobyeo’ was 555 kg per 10a, ‘Hopumbyeo’ was 554 kg, and ‘Chilbobyeo’ was 546 kg. For Cheolwon in mid-mountainous area, the yield was 504 kg per 10a for ‘Daebobyeo’ and 489 kg for ‘Haiamibyeo’. But there was no difference in milled rice yield among cultivars tested in the study at each area. Head rice ratio of ‘Haiamibyeo’, ‘Jinsumibyeo’, and ‘Mipumbyeo’ in Chuncheon was 94.2~95.6% higher than the other cultivars. In Gangreung head rice ratio of ‘Hopumbyeo’, ‘Haiamibyeo’, and ‘Samgwangbyeo’ were 85.2~88.3% but there was no difference among cultivars except ‘Gopumbyeo’ and broken rice ratio of ‘Haiamibyeo’, ‘Samgwangbyeo’, and ‘Mipumbyeo’ were low as 7.5~8.5% and palatability of ‘Mipumbyeo’ was higher than the other cultivars. Head rice ratio of ‘Daebobyeo’ was the highest as 89.2% and there was no difference in broken and chalky rice ratio and palatability among cultivars in Cheolwon. Considering rice yield and quality in major cultivation areas of Gangwon Province, suitable mid-late maturing rice cultivars were ‘Samgwangbyeo’, ‘Haiamibyeo’, and ‘Jinsumibyeo’ in Chuncheon, ‘Daebobyeo’ and ‘Chilbobyeo’ in Gangreung, and ‘Daebobyeo’ and ‘Haiamibyeo’ in Cheolwon. The results obtained in the study imply that the selected cultivars with high yield and quality and suitability to Chuncheon, Gangreung, and Cheolwon, respectively could be recommended to rice cultivating farmers in the regions with high priority.