This study was conducted to evaluate Korean rice cultivars to search any suitable varieties for the northern region of the Korean Peninsula (North Korea). A total of 92 rice varieties which included 74 bred cultivars from South Korea, 13 collections from North Korea and five local cultivars from China, were involved in the evaluating trials for their performance. Stability at three sites inthe northeastern areas of China, which are located in the northern border areas of North Korea, for three years from 2017 to 2019. The ecologically well-adapted rice varieties were selected at each trial site during the first year and employed again as the materials for the subsequent yield trials. A total of six varieties with relatively better performing and stability were selected through the subsequent trials at three sites for three years: Unkwang, Daejin and Taebaek at Dandong region; Hanseol and Taebong at Longjin region; Taebong and Namweon at Hunchun region, respectively. Dandong is located in the southeast parts of Liaoning, which has similar climatic characteristics to the west coastalregion of North Korea. Longjin is located in the middle-east parts of Jilin, which has also similar climatic characteristics to the northern inland region of North Korea. Hunchun is located in the northeastern parts of Jilin, which has presumably similar climatic characteristics to the northern part of the eastern coastal region of North Korea. Unkwang is characterized by its early maturity, with the heading at the 2nd of August, and reveals a yield potential of 7.11 T/ha with resistance to the blast (BL) and the bacterial leaf blade (BLB) diseases. It is predicted to be suitable for the northern area of the Suyang mountain region and the central inland region of North Korea. Daejin has asemi-early maturity heading around the 6th of August and yields of 6.06 T/ha with resistance to BL, BLB, and stripe virus (SV) diseases. Daejin will be adaptable to the northern area of Suyang mountain region. Taebaek is medium maturing variety of Indica/Japonica type. It is heading at the 14thof August with good ripening at maturity, and has yield potential of 6.84 T/ha with resistance to BL, BLB and SV diseases. It will be adaptable to the southern area of Suyang mountain region. Hanseol is early maturing, heading on the 3rd of August, and yields 6.44 T/ha with the short stature and cold tolerance (CT). It will be adaptable to the northern inland and mountainous regions of North Korea. Taebong is semi-early maturingwith the heading at the 6th of August and has a yield potential of 6.96 T/ha with cold tolerane and blast resistance. Taebong was also outstanding in theHunchun region, indicating a more or less wide adaptability in cold areas. It is expected to be adaptable to the northern inland region of North Korea as well as the northern part of the eastern coastal region. Namweon is a medium-maturing variety with aheading date of August 10, and a yield potential of 4.76 T/ha with cold tolerance and resistance to rice neck blast disease. It is expected to be adaptable to the northern part of the eastern coastal region.

The purpose of this study was to select some superior soybean varieties adaptable to growth in the northern parts of the Korean peninsula, and to identify the suitable growing regions of soybean in North Korea. Soybean varieties from South Korea were evaluated with the Chinese locally cultivated varieties as check varieties at two locations, Donggang City of Lianing Province, and at Longjing City of Jilin Province, 2017-2019. A total of 100 soybean varieties from South Korea and three Chinese check varieties were evaluated based on ecological adaptability, and a total of 18 varieties including ‘Suwon 212’ from the Longjing test site as well as a total of 59 genotypes the Donggang test site, were selected for further evaluation in the first experiment year. A total of 12 promising soybean varieties at Longjing and 15 varieties at Donggang that were selected from the previous year, were evaluated at the same sites for ecological adaptability as well as productivity in the second experiment year. A total of nine promising soybean varieties were selected at the test sites, respectively. The nine varieties at each site that were selected from the previous year for the production capacity including flowering date, degree of lodging, yield potential, and disease resistance, were reviewed to evaluate at both sites in the last experiment year. Finally, a total of eight superior varieties, including four at the Longjing site (‘Seonnogkong’, ‘Dajinputkong’, ‘Danweonkong’ and ‘Sinpaldalkong 2’) and the other four at the Donggang site (‘Iksan 13’, ‘Seonnogkong’, ‘Gangil’ and ‘Yeonpung’) were selected. The yield potential of four outstanding soybean varieties selected at the Longjin site was 1.5-2.6t/ha, and that of the other four at the Donggang site was 2.1-2.7t/ha.

한반도 북부 지역에 적응하는 옥수수 품종 개발의 기초연구의 일환으로 2017~2018년 중국 요녕성 동항과 연변주 용정에서 18 품종/교잡계를 파종기, 재식거리 및 시비량 등 관행에 따라 재배하여 출사기 성숙기 반응 및 수량성을 조사하였다. 1. 지역 간의 출사까지의 적산온도 차이가 출사일수의 변이 보다 적으며, 출사일수 차이가 10일 이상인 품종/교잡계는 다청옥, 강다옥, 14GS19/14GS11이었다. 출사일수의 연차변이가 적은 반면 출사까지 적산온도가 큰 경향을 보였다. 2. 동항이나 용정의 적산온도는 북한의 옥수수 숙기 분류기 준에 중간늦종 범위를 벗어나는 늦종 그룹으로 분류할 수 있었다. 용정에서는 북한 성수군 기준의 늦종 재배 가능하며, 동항은 북한의 수풍, 회천, 신포, 양덕, 평강을 잇는 지역에 해당한다. 3. 평균 수량이 10a 당 1,000 kg 이상인 품종은 신황옥 (1,076 kg), 황다옥(1,023 kg), 그리고 중국 비교품종 Xianyu335, Fulai818도 각각 1,013 kg과 1,038 kg이었다. 18개 품종/교잡 계의 대부분이 중간늦종~늦종 군에 분류되었다. 18개 품종/교 잡계의 대부분이 중간늦종~~늦종 군에 분류되었다. 4. 북한의 각 지역별 재배 가능한 성숙군은, 중산지 혜산은 중간종, 북부 선봉은 중간종~중간늦종, 북부 산간인 중강과 동해안 북부 청진지방은 중간늦종~늦종 재배가능지이며, 그 외 지역은 모두 3,000oC 이상으로 늦종 재배에 충분한 적산온도 를 보였다. 북부산간 고지대인 삼지연, 풍산, 장진은 적산온도 2,000oC 이하 지역으로 옥수수 재배가 어려운 지역으로 나타 났다.

1. 본 연구는 우리나라 북부지역과 중국의 북한 인접지역에서 동일 품종을 재배하여 다양한 기후조건에서도 출수일수 변이계수가 안정적이고 조숙성인 품종을 선정하여 북한 적응성이 높은 품종선발에 기초자료로 활용하고자 수행된 연구결과이다. 2. 북한 접경 국내외 6개소에서 출수일수별로 극조생종, 조생종, 준조생종, 중생종의 4개 출수생태형으로 분류하였다. 국내에서는 극조생종에는 9품종, 조생종은 42품종, 준조생종은 17품종, 중생종은 4품종으로 분류되었고 중국에서는 극조생종 7품종, 조생종 27품종, 준조생종 32, 중생종 9품종으로 구분되었다. 3. ‘수원’ 등 국내 3개소에서 출수기의 변이계수는 4.8~ 18.5%이었고 변이계수가 6.0 이하인 품종은 태봉, 내풍, 화동, 운장, 인월, 진봉, 운봉, 금영, 삼천 등 이었다. 4. ‘단동’ 등 중국 3개소에서 출수기의 변이계수는 국내보다 낮은 0.5~8.1%로 변이계수가 2.0 이하인 품종은 태성, 진부찰, 중모1001, 오봉, 새상주, 중모1011, 삼천, 남원, 길주1호(북한 수집) 등 이었다. 5. 한국과 중국의 6개소에서 출수기 변이계수는 8.7~13.3% 의 범위를 보였고, 변이계수가 9.0% 이하로 낮은 품종은 국내 육성 품종 둔내, 운봉, 화동, 진부찰, 설레미 품종으로 북한의 벼 재배지역에서 적응성이 높을 것으로 판단된다. 대비품중으로 북한 대비품종인 원산69호, 중국 대비품종인 길주1호 등도 변이계수가 안정적인 품종이었다.

‘oamibyeo’ a mid-late maturing ecotype with high amylose content in kernels, was developed by the rice breeding team of National Yeongnam Agricultural Experiment Station(NYAES) in 2000 and released in 2001. This variety was derived from the three way cross of Milyang 95//Kimcheonaengmi/2*Ilpumbyeo (in 1992 summer) through the pedigree breeding method and designated as ‘ilyang 168’in 1997. The heading date of ‘oamibyeo’was Aug. 18 in ordinary season with culm length of 85 cm. However, ‘oamibyeo’showed susceptible to bacterial leaf blight, stripe virus and leaf blast disease. The amylose content of ‘oamibyeo’in milled rice kernels is about 26.7% with translucent and clear in chalkness. Thus, ‘oamibyeo’is expected to be used as a source grain for rice noodle industries. The milled rice yield potential of ‘oamibyeo’is about 5.38 MT/ha in local adaptability test of three years and it would be adaptable to Yeongnam plain of Korea.

Analysis of breeding gains in grain yield has been intensively conducted in wheat, barley, oat, maize, and soybean. Such information is limited in rice. The objective of this study was to compare the breeding gains and cultural gains contributed to yield gains of Korean rice varieties since early 1900s. Two sets of yield data were used for analysis; the historical yield data of 1908 for old japonica cultivars, and present yield data in the years from 1996 to 1998 for the six cultivars, consisting of previous two old cultivars and four contemporary cultivars. The old cultivars were two native cultivars, Jodongi and Damageum, while contemporary cultivars were two premium quality japonica cultivars, Hwaseongbyeo and Dongjinbyeo, and two Tongil-type cultivars, high yielding cultivars developed from indica/japonica hybridization, Milyang23 and Dasanbyeo. The yield differences of old cultivars between the experiments in 1908 and the experiments from 1996 to 1998 were estimated as cultural gains (1.84 tons ~textrmha-1 ) due to the improvement of cultivation technology. Yield differences between the old cultivars and contemporary cultivars were considered total yield gains during the periods. These were 2.51 tons ~textrmha-1 for japonica cultivars and 3.81 tons ~textrmha-1 for Tongil-type cultivars. From these data, the genetic gain of 0.67 tons ~textrmha-1 and 1.97 tons ~textrmha-1 were estimated for japonica cultivars and Tongil-type cultivars respectively. The ratio between cultural gain and genetic gain appeared to be 2.7:1 for japonica cultivars and 1:1 for Tongil-type cultivars. This analysis clearly showed the higher genetic contribution in Tongil-type cultivars than in japonica cultivars, suggesting a guideline to be used when planning new yield improvement programs. Additional implication has emerged when a better yield response to modem cultivation technology was found in one of the old cultivars, suggesting the combined improvement between breeding and cultural improvement is necessary for attaining the maximum yield capacity of a crop.

Genetic diversity of 31 rice varieties including 25 japonica and 6 indica varieties was evaluated using a combination of 19 microsatellite or simple sequence repeats (SSRs) and 28 random decamer oligonucle-otide primers. All 19 microsatellite primer sets representing 19 loci in the rice genome showed polymorphisms among the 31 varieties and revealed 91 alleles with an average of 4.80 bands per primer. Also all 28 random decamer primers used were informative and generated 114 non-redundant bands with a mean of 4.07 bands. Microsatellite markers detected higher number of alleles than random primers .although the mean difference was not statistically significant. A cluster analysis based on Nei＇s genetic distances calculated from the 205 bands resolved the 31 varieties into two major groups that correspond to indica and japonica subspecies, which is consistent with the genealogical information. As few as six random decamer primers or a combination of one microsatellite and four random decamer primers were sufficient to uniquely differentiate all 31 varieties. These combinations would be potentially useful in rice variety protection and identification considering that 25 out of 31 varieties used in this study are japonica rices with high grain quality and have close make up.

This experiment was conducted to evaluate genetic variation in 48 rice accessions (Oryza sativa L.) using AFLP and RAPD markers. For AFLP, a total of 928 bands were generated with 11 primer combinations and 327 bands (35.2%) of them were polymorphic among 48 accessions. In RAPD analyses using 22 random primers 145 bands were produced, and 121 (83.4%) were polymorphic among 48 accessions. Each accession revealed a distinct fingerprint by two DNA marker systems. Cluster analysis using AFLP-based genetic similarity tended to classify rice cultivars into different groups corresponding to their varietal types and breeding pedigrees, but not using RAPD-based genetic similarity. The AFLP marker system was more sensitive than RAPD in fingerprinting of rice cultivars with narrow genetic diversity.

Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines (R2 generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine R2 lines (7%) segregated for pubescence and 130 R2 lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine R2 lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.

Three different male-sterile cytoplasmic lines and their common maintainer 'Zhenshan 97B' and two elite restorer lines were used to study cytoplasmic effects on agronomic trait manifestation per se under different nitrogen supply levels. The result showed that cytoplasmic effects could be modified by nitrogen environments. The cytoplasmic effect on grain yield under 150 kg N/ha varied depending on crosses, while it was significantly negative in most crosses under both 60 and 330 kg N/ha. The correlation and path-coefficient analyses suggested that it was expected to improve cytoplasmic effects through reducing maximum tillers and increasing the percentage of productive tillers, leading to increased productive tillers and higher yield in hybrid rice by the aid of cultural practice and genetic transformation. This study also revealed that the same cytoplasm in different combinations had differential effect under the same nitrogen environment, indicating that cytoplasmic effect was produced by interaction of nuclear genes with cytoplasm rather than cytoplasm per se. These results indicated the usefulness of evaluating diverse cytoplasmic sources in various nuclear genotypes bred for hybrid rice breeding program. The finding also suggested that negative cytoplasmic effect could be effectively overcome by elite restorer lines through the interaction of nuclear genes with female cytoplasm.

파종시기 및 수확시기가 쌀의 Amylose 및 단백질함량에 미치는 영향을 알기 위하여 온도 및 일장감응성정도와 단백질함량이 다른 4개품종을 사용하여 4월10일부터 15일간격으로 5회파종하고, 출수후 30일부터 5일간격으로 6회 수확하여 미립내의 Amylose 및 단백질 함량이 품종에 따라 어떤 반응을 보이는가를 검토하였다. 그 결과를 요약하면 다음과 같다. 1. 파종시기가 늦어짐에 따라 Amylose함량은 증가하였고 단배질함량은 감소되었다. 2. 단백질함량의 파종기에 대한 반응은 품종에 따라 달라서 파종기가 지연될수록 조생종은 감소되었고 중만생종은 증가하였다. 3. 파종시기에 따른 단백질함량의 환경변이는 저단백품종보다 고단백품종에서 크게 나타났다. 4. 벼의 Amylose 및 단백질함량에 미치는 수확시기의 영향은 뚜렷하지 않았다. 5. 이상의 결과로 미루어 저Amylose 고단백계통육성을 위해서는 성숙에 지장이 없는한 파종시기를 늦추는 것이 효율이 높고 수확은 출수후 30일부터 가능할 것으로 추론하였다.

고온과 단일이 쌀의 Amylose 및 단백질함량에 미치는 영향을 알기 위하여 일장감응성정도와 단백질 함량이 다른 4개품종을 고온(온실내)과 상온(실외)에서 전생육기간중 계속단일처리, 출수기까지만 단일처리, 출수기이후만 단일처리하고 무처리자연구와 대조하여 쌀의 Amylose 및 단백질함량을 조사비교하였다. 그 결과는 다음과 같이 요약된다. 1. 고온에 의하여 Amylose함량은 2-3% 낮아졌으나 단백질함량은 큰 변화가 없었다. 2. 단일처리로 Amylose함량을 2-5% 저하시켰고 단백질함량을 2-6%증가시켰다. 전생육기간단일에서 가장 크게 영향됐으며 출수전단일이 출수후단일보다 영향이 컸다. 3. 출수후단일조건은 조생종에서 영향이 컸고 출수전 및 전생육기간단일하에서는 고단백품종보다 저단백품종에서 영향이 컸으며 특히 감광성품종인 진흥은 출수전영향이 컸다. 4. 이상의 결과로 미루어 저Amylose 고단백계통육성을 위해서는 장일저온하의 선발이 효율이 높을 것으로 추론하였다.