• 한국잡초학회지
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• 제30권2호
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• pp.68-83
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• 2010

Weedy rice (Oryza sativa L.) occurred sympatrically with other weeds and the rice crop in Malaysian rice granaries. We conducted field surveys in 2006-2008 seasons in 7 farm blocks of Selangor's North West Project, Malaysia to enlist the new biotypes of weedy rice (NBWR) and assess their spatio-temporal pattern of distribution based on quantitative and dispersion indices. No less than 16 accessions of NBWR were identified based on their special traits, viz. panicle type, pericarp colour, presence or absence of awn, seed type and degree of grain shattering. The NBWR accessions exhibited a combination of morphological traits from open panicle, grain with awns, red pericarp, short grain type, and degrees of grain shattering. Others mimic commercial rices with close panicle, awnless grains, white pericarp, long or short grain-type. Invariably, the NBWRs mimic and stand as tall as cultivated rice namely MR219, MR220, or MR235 and these NBWR accessions stand among equals morphologically vis-a-vis the commercial rice varieties. Most accessions displayed varying degrees of grain shattering in excess of 50%, except Acc9 and Acc12. The seasonal dynamics of on the prevalence of dominant NBWR accessions were also displaying significant differences among farm blocks. While Bagan Terap farm block, for example, did not record any measurable changes in the dominant NBWR accessions over seasons, the Sungai Leman farm block recorded measurable season-mediated changes in the dominant NBWR accessions. Sungai Leman started with NBWR Acc3, Acc4, Acc5, Acc7, Acc8, and Acc12 in season 1 of 2006/2007, but no measurable records of Acc3 and Acc5 were shown in season 2 of 2007. In season 3 of 2007/2008, only Acc8 and Acc12 prevailed in the farm block. In Sawah Sempadan farm block, season 3 of 2007/2008 showed much reduced prevalence of NBWRs leaving only Acc8 and Acc12. Most accessions registered clump or under-dispersed spatial distribution pattern based on quantitative indices: variance-to-mean ratio (VMR) and Lloyd's patchiness values. The dynamics on the extent of infestation and prevalence of dominant NBWR accessions registered both season- and farm-block mediated differences. Most accessions showed VMR >1 thus indicative of having a clump or clustered spatial distribution, as exemplified by Acc3, Acc4, Acc7, Acc8 and Acc12 in all farm blocks throughout three seasons. Some accessions have either random or uniform distribution in a few farm blocks. The Acc8 has the highest population counts based on important value index, followed by Acc12, and both were the most dominant accession while Sawah Sempadan was the worst farm block infested by NBWR compared to other farm blocks. These results were discussed in relation with the current agronomic and weed management practices, water availability and extension services in the granary.

• 한국자원식물학회지
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• 제33권6호
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• pp.558-577
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• 2020

Isoflavone contents in soybean seeds are affected by both genetic and environmental factors. Correlation analysis between these factors and isoflavone contents are considered as valuable inputs when breeding improved soybean cultivars. In this study, the seeds of 49 soybean accessions grown in Korea were grouped as black, yellow, green, yellowish-green, pale yellow, and green with a black spot based on their seed coat colors. The contents of 12 isoflavones were analyzed and the association between isoflavone content and seed coat color was determined. The accessions were also grouped as early, intermediate, and late-maturing based on their days to maturity. Out of the 12 isoflavones, 11 were found in 2 accessions, 9 in 18 accessions, 8 in 11 accessions, 7 in another 11 accessions, and 6 in 7 accessions. The total isoflavone content (TIC) in black, yellow, green, yellowish-green, pale yellow, and green with black spot soybeans was in the ranges 2.110 ~ 5.777, 2.487 ~ 4.733, 2.185 ~ 4.413, 2.681 ~ 4.065, 1.827 ~ 4.085, and 3.376 ~ 4.133 mg/g, respectively. The average TIC was highest in green with black spot soybeans (3.616 mg/g), and lowest in pale yellow soybeans (2.875 mg/g). Besides, the average TIC was lowest in early maturing accessions compared to late- and intermediate-maturing accessions. TIC was strongly correlated to malonylgenistin (r = 0.91) and malonyldaidzin (r = 0.78) contents, and poorly correlated to glycitein (r = 0.04) and malonylglycitin (r = 0.18) contents. Also, days to maturity showed strong correlation with malonylgenistin (r = 0.47) content and TIC (r = 0.38). The principal component analysis outlined accessions with high TIC and diverse isoflavones along the first and second components, respectively. The results of the present study depicted that green soybeans with a black spot could be sources of high TIC. Furthermore, late-maturing accessions with diverse isoflavones in their seeds could be useful in future agricultural systems in Korea.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.71-71
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• 2017

Stable stand establishment is pre-requisite in direct rice seeding system for obtaining optimal yield of rice crop in rain-fed and waterlogged areas. Anaerobic condition on waterlogged soil causes low germination which significantly reduces crop yield. Due to low availability of tolerant genetic material for anaerobic germination, there is urgent need to evaluate rice germplasm for better germinability under anaerobic conditions. Seeds of the 185 rice accessions were evaluated for germination vigor and coleoptile length under anaerobic conditions. The variation among germplasm was tested for significance using analysis of variance and various multivariate components. Significant level of variation was observed among all accessions for germination vigor and coleoptiles length. Although highest mean values for coleoptiles length (2.1cm) and germination rate (60%) were observed in japonica accessions but maximum coleoptile length (4.68cm) and germination rate (96%) was found in indica genotype CO18. A highly significant and positive correlation was also observed between germination vigor and coleoptiles length, which signify the importance of elongated coleoptile under anaerobic conditions. The PCA analysis illustrated that 97.24% variation was accounted by PC1 while PC2 and PC3 explained 2.54% and 0.24% variation for germination vigor and coleoptile length. PCA scattered plot divided the accessions in four various groups. All AG tolerant accessions were included in group I. Likewise in the case of cluster analysis, two major clades (I and II) were formed. All accessions showing >40% germination rate were included in clade I, whereas all other accessions with <40% germination rate were grouped in clade II. Further more highly tolerant accessions (>80% germination) were grouped in sub-cluster IA.

• 한국작물학회지
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• 제55권1호
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• pp.47-57
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• 2010

More than 2,500 accessions of squash germplasm are preserved in the National Agrobidiversity Center of RDA, Korea. We investigated the ecological and morphological characteristics on 100 accessions of the squash germplasms with a low viability. Two typical types of oriental squash (Cucurbita moschata) and western squash (Cucurbita maxima) are possessed 89 and 11 accessions, respectively. The origin of 100 accessions was divided into three groups, group I (Korea landraces with 81 accessions), group II (Nepal with 15 accessions) and group III (Russia, Uzbekistan, Laos, and Mexico with each one accession). Seventy eight accessions germinated at $27^{\circ}C$ in growth chamber. Days to first flowering of the female and male flower ranged from 32 days to 67 days and 24 days to 55 days after planting, respectively. Vine length showed the largest variation ranging from 357.8 cm to 1,465 cm, also the average length of ten stem node range has a variable ranges from 92 cm to 217.5 cm. All regenerated squash accessions have an only collided tendril and have three to seven lateral shoots. The flattened globe-shaped squash is the most predominant and exhibited ordinarily round shaped, ball shaped, long oblong-shaped, elongated shape, and pear shape. The average weight of fruit ranged from 1.33 kg to 7.95 kg. Sugar contents showed 5.4~12.6 $Brix^{\circ}$ without ripening period.

• 생명과학회지
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• 제23권11호
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• pp.1305-1310
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• 2013

딜(Anethum graveolens L.)은 세계적으로 중요한 초본으로 양념과 약용뿐만 아니라 소화제, 진정제, 마취제, 활력제로 오래 전부터 사용되어왔다. 딜은 지중해, 서아시아, 중국과 한국 등에서 분포한다. 20개국 100계통 간 rps16-trnK3 서열을 이용하여 유전적 다양성과 유연관계를 조사하였다. 배당된 서열은 747에서 779 염기쌍으로 삽입과 결실이 있었다. 비록 일부 삽입과 결실이 발견되었지만 서열 변이는 염기 치환에 기인하였다. 동아시아 계통이 중앙아시아와 유럽보다 북미에 근연하였다. 딜의 일부 계통은 지리적 분포와 계통도에서 위치가 일치하지 않았지만 rps16-trnK로 잘 분리되었다.

• 한국육종학회지
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• 제40권2호
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• pp.119-127
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• 2008

A total of 41 microsatellite markers were used with 29 genotypes to examine the relationship between SSR polymorphisms and N-use efficiency related traits with a goal to identify the putative QTLs related to these traits. These primers yielded a total of 183 alleles (average 4.46 alleles per primer), and polymorphism information content (PIC) values of the SSRs ranged from 0.119 to 0.805 with mean value of 0.425. Correlation coefficients were obtained among the four N-use efficiency traits in the 34 accessions and significant positive correlations of relative ratios between grain yield and harvest index (r=0.3404) and total dry matter (r=0.7976), while N uptake showed a moderate level of correlation with the ratios of the grain yield and total dry matter, respectively. 36.5% (15/41) SSR markers were monomorphic among the 25 japonica accessions out of the 29 accessions. Association between SSR genotypes and phenotypic performances from the total (29) or japonica (25) accessions was tested based on a single point analysis. Three putative QTL regions were detected for the ratio of grain yield. These include the chromosomal region containing the RM283 locus on chromosome 1 and RM25 on chromosome 8 (all and japonica accessions) and the region with the SSR marker, RM206 on chromosome 11 (the japonica accessions). For the total dry matter ratio, two chromosomal regions were identified as the putative QTL region. One is the region with the SSR marker, RM162 on chromosome 6 (all and japonica accessions) and the other was the one with the SSR marker RM25 on chromosome 8 (the japonica accessions). Among these markers, RM25 showed associations with both traits.

• 농업과학연구
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• 제41권4호
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• pp.309-314
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• 2014

A total of 67 watermelon accessions which include 37 accessions from Korean and 27 accessions from Turkish germplasm and 3 accessions of other related species from USA were investigated for morphological characteristics. The UPOV descriptor list for 56 characters (6 seedlings, 4 plants, 11 leaves, 5 flowers, 23 fruits and 7 seeds) was used in characterization. In addition, eight quantitative characters, hypocotyl length, cotyledon width, cotyledon length, fruit weight, fruit length, fruit width, thickness of outer layer of pericarp and soluble solid content were also measured. The 56 qualitatively scored characters were analyzed by principle coordinate analysis (PCoA) while the eight quantitative ones were subjected to principle component analysis (PCA). Morphological characterization result demonstrated that the accessions displayed high morphological diversity(how much percent?). A high level of phenotypic diversity was observed from the results of morphological characterization. However, plant growth habit and leaf blade flecking showed constant characters for all of the accessions. The Korean and Turkish watermelon genotypes are diverse groups and can be separated by both multivariate analysis of morphological characters although the grouping was more apparent in PCoS results.

• Weed & Turfgrass Science
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• 제2권3호
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• pp.230-235
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• 2013

Amaranths (Amaranthus sp.), an endemic American crop, are now grown widely across the world. This study used 14 simple sequence repeat (SSR) markers to analyze the genetic diversity of 74 amaranth accessions from the United States, with eight accessions from Australia as controls. One hundred twenty-two alleles, averaging eight alleles per locus, were observed. The average major allele frequency, expected heterozygosity, and polymorphism information content (PIC) were 0.44, 0.69, and 0.65, respectively. The structure analysis based on genetic distance classified 77 accessions (94%) into three clusters, while five accessions (6%) were admixtures. Among the three clusters, Cluster 3 had the highest allele number and PIC values, while Cluster 2 had the lowest. The lowest FST was between Clusters 1 and 3, indicating that these two clusters have higher gene flow between them compared to the others. This finding was reasonable because Cluster 2 included most of the Australian accessions. These results indicated satisfactory genetic diversity among U.S. amaranths. These findings can be used to design effective breeding programs involving different plant characteristics.

• The Plant Pathology Journal
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• 제29권1호
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• pp.87-92
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• 2013

This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension ($10^6$ sporangia/ml). At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840) showed moderate resistance and two accessions (IT185446 and IT187904) were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

• 한국자원식물학회지
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• 제25권3호
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• pp.329-338
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• 2012

Genus Taraxacum has been widely used as a folkloric medicine for treatment of diverse diseases. The genetic diversity and relationship among 32 accessions belonging to five Taraxacum species (T. mongolicum T. coreanum, T. coreanum var. flavescens, T. officinale and T. laevigatum) which collected from field, mountain, island and seaside of Korea were evaluated using ISSR markers. A total of 142 ISSR loci detected in the overall species were all polymorphic loci (100%) and interspecies polymorphisms obtained from Korean native and naturalized species were 98.2% and 94.5%, respectively. The genetic similarity matrix (GSM) among 32 accessions ranged from 0.025 to 0.860 with an average of 0.303. According to the clustering analysis, the Korean native species and naturalized species were divided two major clusters. In addition, the different species were divided into independent groups except for the T. coreanum and T. coreanum var. flavescens, and all the 32 accessions could be classified into 7 categories. The study findings indicate that Taraxacum accessions have a high genetic diversity and the dandelion accessions as breeding materials can be effectively utilized for the improvement of Taraxacum breeding.