Effects of Restricted Oxygen, Nitric oxide, and Mercuric Chloride on the Seed Germination and Early Elongation Growth of Rice

Woonho Yang,Jekyu Kim,Alvin J. M. Smucker 韓國作物學會 2006 Korean journal of crop science Vol.51 No.4

Germination and early elongation of rice after germination were investigated in anoxic air treatment, nitric oxide gas treatment, and six concentrations of mercuric chloride solutions to determine the effects of limited oxygen environment, nitric oxide, and inhibited water flux through cell membrane in 17~circC . Anoxic air treatment affected germination of tested six varieties very little. However root elongation rates were severely inhibited while shoot growth was affected less. Reductions in shoot and root elongations demonstrated genotypic variations. Nitric oxide delayed the germination of rice even though it didn't affect the final percent germination. Elongations of root and shoot were inhibited in nitric oxide treatment. The inhibitor effect of nitric oxide on the shoot elongation of rice was less severe, while nitric oxide completely inhibited the root emergence of rice. Concentrations of HgCl2 greater than 300~muM dramatically reduced the rate and percentage of germination when compared to distilled water treatment. The reduced percent germination showed the greatest variation among rice varieties in 500~muM solution of mercuric chloride. Ansanbyeo, Jinheung, and Odaebyeo were affected less by HgCl2 , Nonganbyeo and Sangmibyeo were intermediate, and the germination of Andabyeo was greatly reduced by HgCl2 . Root elongation of germinated rice seedlings was more sensitive to oxygen deficits, nitric oxide, and HgCl2 treatments than germination and shoot elongation. In conclusion, poor seedling establishment of rice sown in flooded paddy soils, in which the oxygen supply to the seeds is restricted, appears to the result of limited root elongation rate.

Grain Yield and Yield Attributes of New Plant Type and Hybrid Rice

Yang, Woonho,Peng, Shaobing,Laza, Rebecca C.,Visperas, Romeo M.,Dionisio-Sese, Maribel L. Crop Science Society of America 2007 Crop science Vol.47 No.4

Characterization of Biomass Production and Seedling Establishment of Direct-Seeded Nogyangbyeo, a Whole Crop Rice Variety for Animal Feed

Woonho Yang,Kyung-Jin Choi,Kang-Su Kwak,Tae-Shik Park,Min-Hyuk Oh,Jin-Chul Shin,Jong-Geun Kim 韓國作物學會 2007 한국작물학회지 Vol.52 No.3

Experiments were conducted with aims to (1) estimate the biomass yield potential, (2) characterize the biomass and digestible dry matter production, and (3) reveal the characteristic seedling establishment of a whole crop rice variety, Nogyangbyeo, in dry- and wet-seeded rice. Maximum aboveground total biomass of Nogyangbyeo was 18 t ha-1 in dry-seeded rice and 20 t ha-1 in wet-seeded rice. Biomass yield potential of Nogyangbyeo was lower than that of Dasanbyeo. Comparatively, Nogyangbyeo was straw-dependent and Dasanbyeo was grain-dependent for biomass accumulation. Percentage of digestible dry matter (DDM) was higher in panicles than straw. Digestible dry matter yield was determined mainly by biomass yield rather than DDM percentage. Number of seedling establishment in Nogyangbyeo was 73m-2 in dry-seeded rice and 109m-2 in wet-seeded rice. Poor seedling establishment of dry-seeded Nogyangbyeo in the field condition was the result of low seed germination under low temperature and poor seedling emergence by deep sowing. Low seedling emergence rate of Nogyangbyeo was attributed mainly to slow elongation growth by slow leaf development and partly to mesocotyl and 1st internode lengths, not to genetically defined leaf length. The slow elongation growth of Nogyangbyeo was the same even in the high daily mean temperature of 24~circC . Results suggest DDM yield in rice can be improved simply by increasing biomass and whole crop rice varieties should be adaptable to direct-seeding.

Association of Grain Filling Duration and Leaf Activity with the Grain Yield in Field-Grown Temperate Japonica Rice

Yang, Woonho,Kang, Shingu,Park, Jeong-Hwa,Kim, Sukjin,Choi, Jong-Seo,Heu, Sunggi The Korean Society of Crop Science 2018 한국작물학회지 Vol.63 No.2

Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during the grain filling period to an appropriate environment plays a key role in achieving a high grain yield in temperate rice. Field experiments were conducted for two consecutive years with two planting times to assess the relations among grain filling traits, loss of leaf activity during the ripening period, and the grain yield of temperate japonica rice with wide environmental variation. Higher grain yields were attained in 2017 than in 2016 and with late planting than with early planting. The high grain yield accompanied a comparatively lesser increase in grain weight at the early filling stage but more gain in grain weight occurred during the late filling stage. Final grain weight correlated positively with grain filling duration but negatively with grain filling rate. Extended grain filling duration was associated with higher cumulative temperature and cumulative solar radiation for an effective grain filling period. The reduction in SPAD value ${\times}$ leaf dry weight from heading to harvest significantly correlated with final grain dry weight in a positive manner. No significant relation was found between grain filling duration and the decrease in SPAD value ${\times}$ leaf dry weight during the grain filling period. The results suggest that grain filling duration and loss of leaf activity during ripening independently contribute to environmentally induced yield improvement in temperate japonica rice.

Re-examination of the Standard Cultivation Practices of Rice in Response to Climate Change in Korea

Woonho Yang,조현숙,Mihyang Kim,Ki-Yeong Seong,박태선,Myung-ChulSeo,Hang Won Kang 한국작물학회 2013 Journal of crop science and biotechnology Vol.16 No.2

The impact of climate change has been simulated or estimated to bring about yield decline and quality deterioration of rice in Korea, a temperate country. To cope with these negative impacts, here we propose likely changes in the standard cultivation practices of rice in consideration of the current information on the progress/prediction of climate change and related physiological aspects of rice. Shifting grain-filling period could be a promising choice to optimize temperature for rice grain-filling, a crucial growth stage to productivity, hence providing rice plants with sufficient duration and solar radiation for the period. This choice, however, shortens days to flowering by the additive combined effects of high temperature by delayed transplanting, temperature rise itself by climate change, and accelerated phase change of rice by high temperature and short day-length. These combined effects may delay the time of transplanting in a great extent, hence reducing biomass accumulation of rice before flowering. In these conditions, recovering decreased biomass production is the key concern for rice productivity. This includes raising healthy seedlings by omitting the covering process, dense planting, and nutrient management to enhance plant’s uptake activity. Current standard water management, especially mid-term drainage and intermittent irrigation, would have more importance in the future since they mitigate methane emission from the paddy. Field monitoring for weeds and pests would be an important first step to identify newly developing or thriving species for establishing subsequent controlling strategies. Earlier weed control should be emphasized through adjusting time of herbicide application

Association of Duration and Rate of Grain Filling with Grain Yield in Temperate Japonica Rice (Oryza sativa L.)

Woonho Yang,Taeshik Park,Kangsu Kwak,Kyungjin Choi,Minhyuk Oh 한국작물학회 2007 Korean journal of crop science Vol.52 No.1

Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops’ yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate. Grain filling rate and duration exhibited highly significant variations in the ranges of 20.7~46.3 g m-2 d-1 and 11.2~35.5 days, respectively, depending on rice genotypes. Grain yield on unit area basis was associated positively with grain filling duration but negatively with grain filling rate. Grain filling rate and duration were negatively correlated with each other. Final grain weight increased linearly with the rise in both cumulative mean temperature and cumulative solar radiation for effective grain filling. Higher cumulative mean temperature and cumulative solar radiation for effective grain filling were the results of longer grain filling duration, but not necessarily higher daily mean temperature and daily solar radiation for effective grain filling. Grain filling rate demonstrated an increasing tendency with the rise in daily mean temperature for effective grain filling but their relationship was not obviously clear. It was concluded that grain filling duration, which influenced cumulative mean temperature and cumulative solar radiation for effective grain filling, was the main factor that determined grain yield on unit area basis in temperate japonica rice.

Re-examination of the Standard Cultivation Practices of Rice in Response to Climate Change in Korea

Yang, Woonho,Cho, Hyeoun Suk,Kim, Mihyang,Seong, Ki Yeong,Park, Tae Seon,Seo, Myung Chul,Kang, Hang Won 한국작물학회 2013 Journal of crop science and biotechnology Vol.16 No.2

The impact of climate change has been simulated or estimated to bring about yield decline and quality deterioration of rice in Korea, a temperate country. To cope with these negative impacts, here we propose likely changes in the standard cultivation practices of rice in consideration of the current information on the progress/prediction of climate change and related physiological aspects of rice. Shifting grain-filling period could be a promising choice to optimize temperature for rice grain-filling, a crucial growth stage to productivity, hence providing rice plants with sufficient duration and solar radiation for the period. This choice, however, shortens days to flowering by the additive combined effects of high temperature by delayed transplanting, temperature rise itself by climate change, and accelerated phase change of rice by high temperature and short day-length. These combined effects may delay the time of transplanting in a great extent, hence reducing biomass accumulation of rice before flowering. In these conditions, recovering decreased biomass production is the key concern for rice productivity. This includes raising healthy seedlings by omitting the covering process, dense planting, and nutrient management to enhance plant's uptake activity. Current standard water management, especially mid-term drainage and intermittent irrigation, would have more importance in the future since they mitigate methane emission from the paddy. Field monitoring for weeds and pests would be an important first step to identify newly developing or thriving species for establishing subsequent controlling strategies. Earlier weed control should be emphasized through adjusting time of herbicide application.

Association of Duration and Rate of Grain Filing with Grain Yield in Temperate Japonica Rice (Oryza sativa L.)

Woonho Yang,Taeshik Park,Kangsu Kwak,Kyungjin Choi,Minhyuk Oh 韓國作物學會 2007 Korean journal of crop science Vol.52 No.1

Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops' yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate. Grain filling rate and duration exhibited highly significant variations in the ranges of 20.7~46.3~;g~;m-2d-1~;and~;11.2~35.5 days, respectively, depending on rice genotypes. Grain yield on unit area basis was associated positively with grain filling duration but negatively with grain filling rate. Grain filling rate and duration were negatively correlated with each other. Final grain weight increased linearly with the rise in both cumulative mean temperature and cumulative solar radiation for effective grain filling. Higher cumulative mean temperature and cumulative solar radiation for effective grain filling were the results of longer grain filling duration, but not necessarily higher daily mean temperature and daily solar radiation for effective grain filling. Grain filling rate demonstrated an increasing tendency with the rise in daily mean temperature for effective grain filling but their relationship was not obviously clear. It was concluded that grain filling duration, which influenced cumulative mean temperature and cumulative solar radiation for effective grain filling, was the main factor that determined grain yield on unit area basis in temperate Japonica rice.

중국 단동 지역에서 국내 벼 품종의 출수 반응과 적응 출수생태 특성

양운호(Woonho Yang),Hongguang Ju,김정주(Jeong-Ju Kim),한아름(Areum Han),양정욱(Jung-Wook Yang),김은영(Eun Young Kim),강신구(Shingu Kang),이대우(Dae-Woo Lee),채미진(Mi-jin Chae),신명나(Moung Na Shin),Dongchun Jin,Jin Piao,Jichun 한국작물학회 2023 한국작물학회지 Vol.68 No.3

1. 벼 재배기간에 단동 지역의 평균기온은 북한의 신의주보다 약간 낮게, 수풍보다는 약간 높게 경과하였으며, 이들세 지역의 일장 변화는 거의 동일하였다. 2. 시험 연도와 이앙시기에서 공통적으로 단동 지역의 안전출수한계기와 현지 품종 중 가장 늦은 출수기까지 출수한 국내 품종은 조생종 8개(진부올, 백일미, 조운, 진옥, 조평, 진부, 산호미, 오대)였으며, 북한 품종은 5개(올벼2, 선봉9, 온포1, 길주1, 평도15)였다. 3. 국내 13품종과 북한 7품종의 기본영양생장성은 12~43 일, 감광성은 3~56일, 감온성은 15~33일 범위였는데, 국내 중생 및 중만생 3품종(선품, 신보, 소비)과 북한 평양21은 감광성이 33~56일로 컸고, 다른 3품종(아세미, 진미, 평도5)은 기본영양생장성이 40~43일로 큰 특징을 보였다. 4. 단동 시험포장에서 나타난 벼 품종의 출수기는 감광성과고도로 유의한 정의 상관을 나타내었으며, 감광성이 컸던 중생과 중만생 3품종을 제외하면 기본영양생장성과유의한 정의 상관관계가 인정되었다. 5. 단동 지역의 벼 재배기간에 적응하는 품종은 기본영양생장성 35일 이하와 감광성 25일 이하를 모두 충족하는 출수생태 특성을 보였다. We examined the heading responses of rice varieties over two years in Dandong, China to select the varieties that are adaptable to the bordering northwestern plains of North Korea. Dandong had slightly lower mean temperature than Sinuiju, North Korea but slightly higher than Supung, but it had almost the same day-length as the two regions in North Korea. In the two experimental years and two transplanting-date treatments, eight varieties (Jinbuol, Baegilmi, Joun, Jinok, Jopyeong, Jinbu, Sanhomi, and Odae) from South Korea and five varieties (Olbyeo2, Sonbong9, Onpo1, Gilju1, and Pyongdo5) from North Korea reached the heading stage not later than the latest heading dates of Dandong domestic varieties and the safe marginal heading dates of Dandong. We examined the basic vegetative phase (BVP), photoperiod-sensitivity (PS), and thermo-sensitivity (TS) of rice heading in a phytotron study to characterize the heading ecotypes of rice varieties adaptable to Dandong. For the rice varieties grown in Dandong experimental field, number of days to the heading stage was highly positively correlated with PS and, except middle and mid-late maturing three varieties, it was significantly positively correlated with BVP. Two-dimensional distribution plotting revealed that both 35 days or less BVP and 25 days or less PS were the characteristic heading ecotypes of the rice varieties adaptable to Dandong.

기온에 따른 벼 출수기 생육 반응 및 남한에서 북한 적응 품종 육성을 위한 출수기 목표 생장량 추정

양운호 ( Woonho Yang ),최종서 ( Jong-seo Choi ),이대우 ( Dae-woo Lee ),강신구 ( Shingu Kang ),이석기 ( Seuk-ki Lee ),채미진 ( Mi-jin Chae ) 한국농림기상학회 2021 한국농림기상학회지 Vol.23 No.2

본 연구는 북한 적응 벼 품종을 남한의 유사 기후 지역에서 육성하는 경우, 북한 지역별로 육성모지 수준의 생장을 위한 출수기 목표 생장량을 추정하기 위하여 기온이 서로 다른 지역(수원, 철원, 진부)에서 6품종의 출수기 벼 생장 반응을 검정하고 북한 지역의 기온에 적용하여 분석하였다. 시험지역, 연도를 합하여 품종의 최고값 대비 지수 성적을 분석하였을 때, 이앙기-출수기 기간의 평균기온과 출수기 초장 및 건물중은 고도로 유의한 2차 함수식의 관계를 보였으며, 초장 최고값은 23.2 ℃, 건물중 최고값은 22.8 ℃에서 나타났다. 각각의 품종에서 이앙기-출수기 평균기온이 낮아짐에 따라 출수 소요일수는 증가하였으나, 출수소요 적산온도는 지역간 차이가 적고 비교적 일정하였다. 시험지역의 토양 특성 차이에 의한 출수기 벼 생육 차이는 적었으며, 시험지역의 기온 처리에 의한 출수기 건물중은 현지시험에서와 같은 양상이었다. 현지시험에서 나타난 품종별 출수소요 적산온도를 북한 지역의 평균기온과 안전 출수 한계기에 대입하여 비교한 결과, 5지역(개성, 해주, 사리원, 남포, 평양)은 중생종 까지, 14지역(용연, 신계, 안주, 구성, 신의주, 장전, 원산, 함흥, 평강, 양덕, 희천, 수풍, 신포, 강계)은 조생종만 재배 가능하며, 4지역(김책, 청진, 선봉, 중강)은 출수가 가장 빨랐던 조품도 적응하지 못하는 것으로 분석되었다. 북한의 중생종 재배 가능 5지역은 이앙기-안전 출수 한계기 평균기온이 수원보다 0.7∼1.2 ℃ 낮았으며, 이들 지역에서는 수원에서 육성한 중생종을 동일한 방법으로 재배하면 수원과 비슷한 수준의 출수기 생장량을 보이는 것으로 분석되었다. 조생종 재배만 가능한 14지역 중 9지역(용연, 신계, 안주, 구성, 신의주, 장전, 원산, 희천, 수풍)의 이앙기-안전 출수 한계기 평균기온은 22.2∼23.0 ℃로 철원의 22.9 ℃와 차이가 크지 않았으며, 철원에서 육성한 조생종을 재배하면 철원과 비슷한 수준의 출수기 생장량을 나타내는 것으로 분석되었다. 철원과 같은 수준의 조생종 출수기 생장량 확보를 위해서는 함흥과 강계의 경우 철원에서 나타나는 초장보다 4cm 긴 품종, 평강과 양덕 및 신포의 경우에는 초장은 8∼14cm, 주당 건물중은 2∼4g 큰 품종을 육성해야 하는 것으로 분석되었다. 종합적으로, 북한 적응 품종을 남한의 유사 기후 지역에서 육성하는 경우, 중생종 재배 가능 지역은 수원, 조생종 재배 가능 지역 중 철원과 기온이 비슷한 지역은 철원에서 육성한 품종을 재배하면 출수기 생장량이 비슷하며, 철원보다 기온이 낮은 지역에 대하여는 철원에서 나타나는 것보다 더 큰 출수기 생장량을 보이는 품종을 육성해야 할 것으로 판단되었다. Field studies at Suwon, Cheorwon, and Jinbu were carried out to determine the relationship between mean temperature from transplanting to heading (MT) and growth at heading stage of rice. Plant height (PH) and dry weight (DW) at heading stage were significantly correlated with MT, showing second degree polynomials. The optimal temperatures for PH and DW were 23.2 ℃ and 22.8 ℃, respectively. Little differences in rice growth among soils collected from the experimental sites and the temperature-response in a phytotron study supported that MT was the main determinant of the growth shown in the field study. Though number of days to heading increased as MT decreased, cumulative temperatures (CT) affected by sites and MT for given varieties were fairly constant. When applying specific CT for each of the varieties to the temperature in North Korea, (1) five regions (Kaesong, Haeju, Sariwon, Nampo, Pyongyang) were suitable for early to mid-maturing varieties and (2) 14 regions (Yongyon, Singye, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) were suitable only for early-maturing varieties. In (1) regions, the similar extent of growth with that in Suwon could be achieved when mid-maturing varieties grown in Suwon are cultivated. Among (2) regions, early-maturing varieties are expected to demonstrate the similar extent of growth with that in Cheorwon in 9 regions except Hamhung, Kanggye, Pyonggang, Yangdok, and Sinpo. For Hamhung and Kanggye, the target PH was assessed as 4cm higher than that shown in Cheorwon. Plant height of 8 -14cm and DW of 2-4g per hill greater than those shown in Cheorwon were the target growth for Pyonggang, Yangdok, and Sinpo to attain the similar amount of growth with that in Cheorwon. It is suggested that rice varieties for North Korea could be bred by adjusting the target growth at the breeding sites in South Korea.