Rice ratooning is the cultural practice that easily produces secondary rice from the stubble left behind after harvesting the main crop. ‘Daol’ is an extremely early growing rice variety. Planting this variety early allows for an additional ratoon harvest after the primary rice harvest. The plant growth and yield of ratoon rice were very low compared to those of main rice. Protein, amylose content, and head rice rate were higher in ratoon rice than in main rice. The distribution by the rice flour particle size of main and ratoon rice was similar. The damaged starch content in ratoon rice was relatively high at 6.1%. Ratoon rice required a longer time and higher temperature for pasting than main rice. Compared to the original rice, peak viscosity (PV), hot paste viscosity (HPV), cool paste viscosity (CPV), and breakdown (BD) were very low, and setback (SB) was high. As a result of analyzing the gelatinization properties of main and ratoon rice using differential calorimetry, it was found that the onset (To), peak (Tp), and conclusion (Tc) of ratoon rice starch were processed at a lower temperature than those of main rice. The gelatinization enthalpy of both samples was similar. The distribution of amylopectin short chains in ratoon rice was higher than that in main rice.

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.

향후 쌀 생산량 조정과 조사료 자급률 향상을 위해 사료용 벼 재배면적이 확대될 시기에 국내 총체사료용 벼 종자생산체계 확립에 기술적 기초자료를 확보하기 위해 총체사료용 벼 주요품종의 채종적지 선정에 관해 검토한 결과는 아래와 같다. 1. 벼 재배 지대별 10개소 중 ‘녹양’은 I-2지대 남부해안지인 고성, II-1지대 호남평야지인 익산, II-2지대 영남평야지인 밀양 지역이 충실한 종자를 채종하기에 적합한 지역으로 조사되었다. 그 중에서도 고성지역에서 4월 30일에 파종하여 5월 30일에 이앙했을 때 생육, 수량 및 발아특성이 가장 좋아 채종적지로 가장 적합할 것으로 판단된다. 2. ‘목우’는 I-2지대 남부해안지인 고성, II-1지대 호남평야지인 익산지역이 우량 종자를 채종하기에 적합한 지역으로 보인다. 특히 남부해안지인 고성에서 파종시기를 앞당겨 4월 1일에 파종하여 4월 30일에 이앙했을 때 가장 건전한 종자를 채종할 수 있을 것으로 판단된다. 3. ‘목양’은 지대별로 공시한 다른 3품종과 비교했을 때 등 숙비율, 발아율 등이 대체로 낮아 다른 3품종보다는 채종적지로서의 조건이 다소 미흡하지만 I-2지대 남부해안지인 고성, II-1지대 호남평야지인 나주지역이 채종하기에 적합한 것으로 나타났다. 남부해안지인 고성에서는 ‘목우’와 마찬가지로 4월 1일 에 파종하여 4월 30일에 이앙했을 때 가장 건전한 종자를 얻을 수 있으나 평균발아율이 85%미만으로 건전한 발아를 위해서는 채종한 종자를 최소한 반드시 수선하여 사용해야 하며 수선 시에는 채종량에 비해 종자량의 손실이 많을 것으로 판단된다. 4. ‘중모1029’의 경우에는 지대별로 시험한 10개소 중에서 II-2지대 영남평야지에 속하는 대구지역이 생육, 수량 및 발아 특성을 고려해 볼 때 채종적지로 판단된다.

The relationship between mean air temperature after heading and starch characteristics of colored rice grains was investigated using three colored rice cultivars. Pasting temperature within each rice cultivar with different harvest times differed. The pasting temperatures of two rice cultivars, Hongjinju and Joseongheugchal, reached the highest at 40 days after heading and decreased during the late harvest time. Distribution of amylopectin in the Hongjinju rice cultivar at the earlier harvest time contained a greater number of very short chains with the degree of polymerization (DP) between 6 and 12 and fewer chains with a DP from 13 to 24 than that of the later harvest time. However, there was little difference in the distribution of the longer chains of 25 ≤ DP ≥ 36 and 37 ≤ DP for latter harvest times compared to that of the earlier ones. It was suggested that the structure of amylopectin affected the varietal differences in patterns of chain length of amylopectin during grain filling. In addition, the control of ripening was different from that causing the pigment effects in the fine structure of amylopectin in the three colored rice cultivars. Larger starch granules were observed in the Joseongheugchal rice cultivar and smaller granules occurred in the Hongjinju rice cultivar. The present study revealed that later harvest times led to a clear increase in the mean granule size of starch in the three colored rice cultivars.

Rice quality should be considered as a primary consumer requirement. Regarding marketing, characteristics such as appearance, physicochemical properties, and palatability of brand rice are of high economic importance. Therefore, this study was conducted to select the optimal rice cultivars representing the commercial rice brands of Gyeongsangbuk-do province in Korea. Various rice grain quality components, grain appearance, several physicochemical properties of rice grain, and texture or palatability of cooked rice grains of ten cultivars (namely ‘top quality rice’) cultivated at three different locations, such as inland mountainous and southern plain areas of Gyeongsangbuk-do province in 2013~2014, were evaluated, and the obtained data was analyzed. ‘Hiami’ showed slightly higher protein contents and lower palatability of cooked rice than the other rice cultivars. Rice production and head rice yield produced at Gumi were the highest. The protein content of milled rice produced at Andong, an inland mountainous region, was approximately 0.3% point lower than that from other locations, whereas the amylose content of milled rice was approximately 1% point higher than those from the other plain regions, Daegu and Gumi. We evaluated the texture, Glossiness value determined using a Toyo teste meter and palatability of cooked rice of ten cultivars. The hardness of cooked rice produced in Andong was slightly lower than that produced in Daegu and Gumi, and additionally, the palatability of cooked rice produced in Andong was the best, followed by that producted in Gumi and Daegu. Considering rice yield and grain quality in the major rice cultivation areas of Gyeongsangbuk-do province, the rice cultivars that may be suitable for each region could be recommended mid-late maturation: ‘Younghojinmi’ and ‘Mipum’ in Daegu, ‘Daebo’, ‘Samgwang’, Chilbo’ and ‘Younghojinmi’ in Gumi, ‘Samgwang’, ‘Jinsumi’ and ‘Sukwang’ in Andong. These results obtained in this study imply that the selected cultivars with high yield and quality could be recommended with high priority to rice farmers in the regions.

The study was carried out to determine the changes of growth characteristics, anthocyanidin, and brown rice yield grown at coast and inland areas apart from the east coastline of Gyeongsangbuk-do province. Number of spikelets per panicle was much more increased in inland area. Regional difference in number of spikelets per panicle was observed in Jeongjinju cultivar. Among these red rice cultivars, the highest brown rice yield was Jeongjinju rice cultivar having 702 ㎏ in inland area and 692 ㎏ in coast area, respectively. Anthocyanidin content ranged 524 to 610 ㎍/g dry weight basis. Cyanidin content was 11.4 to 14.0 times higher than that of delphinidin under coast and inland area. Anthocyanidin content was higher in rice cultivar grown at coast area. Highest head brown rice rate was only observed in Geonganghongmi to 95.2 at coast area and 95.4 inland area. In considering brown rice yield and pigment content, Hongjinju rice cultivar was recommended in optimal pigment rice cultivar in eastern coast of Gyeongsangbuk-do Province.

Three different transplanting dates for two rice cultivars grown in Daegu, Republic of Korea, were examined to identify the changes in growth, rice quality, and characteristics of amylopectin. An early transplanting date caused a reduction in the number of panicles in both rice cultivars compared to that in the optimal and late transplanting dates. The 1000-grain weight in the two rice cultivars was significantly increased in the late transplanting date. The rice cultivar tolerant to high temperatures, Donganbyeo, exhibited the lowest milky grain rate in the late transplanting date. The highest rate of head grain was observed in the late transplanting date in both rice cultivars. Regarding the pattern of pasting properties, peak viscosity increased with delayed transplanting dates. With respect to changes in the amylopectin branch-chain length distribution, the amylopectin structure of the translucent Dongan rice cultivar transplanted on April 25 was characterized by a significant increase in A chains with DP > 12, and a decrease in long chains DP ≥ 37 compared to that transplanted on June 25. In contrast, the amylopectin structure of the chalky Dongan rice cultivar transplanted on April 25 exhibited further decrease in 13 < DP < 19 than that transplanted on June 25. In the Ungwang rice cultivar, the amylopectin structure of the translucent Ungwang rice cultivar transplanted on April 25 and June 25 was characterized by a significant decrease in the lengths of total amylopectin chains. Furthermore, the amylopectin structure of the chalky Ungwangbyeo rice cultivar transplanted on April 25 was characterized by a significant increase in 7 < DP < 30, while a significant decrease was observed in that transplanted on June 25. These results indicate that the amylopectin structure is altered by different transplanting dates depending on the characteristics of the rice cultivar.

Rice (Oryza sativa L.) ratooning is the production of a second rice crop from the stubble left behind after the main crop harvest. The objectives of this study were to evaluate the effects of main-crop stubble height, irrigation and fertilization on ratoon grain yield. Main crop ‘Jinbuol’ rice cultivar was harvested to leave with 10, 20, 30, or 40 cm stubble height. When the main crop stubble was harvested with 10 cm height, ratoon rice grain yield was increased by 2,810 kg/ha. Irrigation on stubbles after main crop harvest did not affect the ratoon crop yield and rice quality. The results showed a large variation in the ratoon performance by fertilizer application methods. Top-dressed nitrogen fertilizer on the stubble after harvest caused increase in panicle production and higher maturity rate. However, there was no significant difference in protein content, amylose content of milled rice and cooked rice characters between plots managed with and without nitrogen fertilizer.

Relationship between grain quality-related traits and daily mean temperature/sunshine hours during grain filling stage was analyzed using eleven high quality rice varieties at 24 experimental sites through eight provinces of Korea in 2013~2014. In the data set pooled across varieties, experimental sites and years, grain quality-related traits such as percentage of head rice (PHR), head rice yield (HRY), protein in milled rice (PRO) and Toyo Mido Meter glossiness value (TGV) were higher at the temperature lower than 22.6℃ for 40 days after flowering (DAF), which was optimum for percentage of grain filling in this study. Optimum sunshine hours for 40 DAF were 6.0~6.1 hr d -1 when considered PHR, HRY and TGV. PRO was associated with daily mean temperature and sunshine hours for 40 DAF in more varieties than the other traits. PRO was closely correlated with daily mean temperature during early filling stage and sunshine hours during early to mid filling stage, compared to other stages during grain filling. It is concluded that general trend in the variation of grain quality-related traits could be explained by the changes in daily mean temperature and sunshine hours during grain filling. In addition, climate conditions during early grain filling stage played important roles to enhance grain quality.

움벼는 수확된 벼의 그루터기에서 2차 분얼이 발생하여 이로부터 새로운 수확물을 얻어내는 것으로 비교적 평균기온이 높은 대구지역에서의 극 조생종, 조생종 및 중만생종 벼의 움벼재배 가능성을 검토하였다. 움벼재배에 적합한 품종은 극조생인 진부올, 조운, 조생종인 주남조생이 가능한 것으로 판단되며, 움벼의 생육기간은 생리적 혹은 환경적인 작기의 종료로 본포의 생육기간보다 짧았다. 초장은 36~70%로 짧고, 이삭수도 줄어들었으며 특히 이삭수는 품종별 차이가 현저하였다. 출수 소요일수는 본포 벼의 수전일수가 3~6일 인데 비해 움벼의 경우 출수 시작부터 출수 정지까지 오랜 기간 출수가 진행되었다. 본 시험에서 움벼생산이 가능한 세가지 조생품종에 대하여 본포의 생육기간은 110~112일 정도에 비해 움벼의 생육기간은 60~65일 정도로 최소 1개월 정도 생육기간이 짧았으며 수확량은 본포수량의 25~33%정도로 나타났다. 본포에서 생산된 쌀에 비해 움벼에서 생산된 쌀의 단백질 함량과 아밀로스함량이 유의하게 높았다. ToYo 미도메터가 나타내는 간접 식미치인 윤기치가 본포에서 수확한 쌀보다 높게 다소 높게 나타났는데 이는 아밀로스 함량이 본포보다 움벼에서 높게 나타났기 때문인 것으로 판단되며, 밥의 외관, 경도, 점도 및 발란스 수치로 환산하는 취반 식미값의 경우는 본포에서 수확한 쌀로 지은 밥에 비해 움벼는 현저하게 낮았다. 본포 수확벼에 비해 움벼로 지은 밥의 경도와 탄력성은 같거나 높아지고, 점성과 찰성은 떨어지는 경향이었다. 본포와 움벼 종자의 발아력은 조운벼를 제외한 진부올과 주남조생의 경우 통계적 유의성이 없었다.

Anthocyanin pigments from three pigmented rice varieties, Hongjinju, Sintoheugmi and Josaengheugchal pigmented by black color, were quantified to evaluate effects of transplanting and harvesting time during seed development. Hongjinju, a rice variety of grains pigmented by red color, contains only two kinds of anthocyanins, delphinidin and cyanidin. Meanwhile, delphinidin, cyanidin, and pelargonidin were identified in Sintoheugmi and Josaengheugchal. Anthocyanidin contents in pigmented rice variety Hongjinju under different planting times were decreased with prolonged harvesting times. The Sintoheukmi showed that cyanidin content was the highest among analyzed pigments during seed development. Two anthocyanins (cyanidin and pelargonidin) in Josaengheugchal recorded highest contents at 20 days after heading in three transplanting times. Cyanidin content was also slightly increased with prolonged transplanting time. Total anthocyanidin contents in Hongjinju were always lower than that of Sintoheukmi and Josaengheukchal. In two rice varieties, Sintoheugmi and Josaengheugchal, a* values were commonly slightly decreased by late transplanting and harvesting times. Changes of a* and b* values in waxy rice varieties, Sintoheugmi and Josaengheugchal varied more than those in Hongjinju. In Josaengheugchal, early harvesting before maturity showed lower brown rice yield and late harvesting in the each transplanting times resulted in highest brown rice yield.

A simplified technique which cryoprotects zygotic embryos by encapsulation-dehydration was developed for the germplasm conservation of herbaceous peony (Paeonia lactiflora Pall.). The highest survival rate (85~%) was obtained from embryos treated by encapsulation-dehydration. The zygotic embryos were precultured on MS medium containing 0.3mg/L GA3 for 1 day. The precultured embryos were encapsulated in 3~% (w/v) alginate beads and immersed for 1 h in MS medium containing 2 M glycerol and 0.5 M sucrose. The encapsulated embryos were dehydrated for 5h by air drying prior to direct immersion in liquid nitrogen. This encapsulation-dehydration method appears to be a promising technique for germplasm cryopreservation of a herbaceous peony.