• The Plant Pathology Journal
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• 제26권4호
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• pp.313-320
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• 2010

Genetic instability of the rice blast fungus Magnaporthe oryzae has been suggested as a major factor underlying the rapid breakdown of host resistance in the field. However, little information is available on the mechanism of genetic instability. In this study, we assessed the stability of repetitive DNA elements and several key phenotypic traits important for pathogenesis after serially transferring two isolates though rice plants and an artificial medium. Using isolate 70-15, we obtained a total of 176 single-spore isolates from 10 successive rounds of culturing on artificial medium. Another 20 isolates were obtained from germ tubes formed at the basal and apical cells of 10 three-celled conidia. Additionally, 60 isolates were obtained from isolate KJ201 after serial transfers through rice plants and an artificial medium. No apparent differences in phenotypes, including mycelial growth, conidial morphologies, conidiation, conidial germination, appressorium formation, and virulence, or in DNA fingerprints using MGR586, MAGGY, Pot2, LINE, MG-SINE and PWL2 as probes were observed among isolates from the same parent isolate. Southern hybridization and sequence analysis of two avirulence genes, AVR-Pita1 and AVR-Pikm, showed that both genes were also maintained stably during 10 successive generations on medium and plants. However, one reversible loss of restriction fragments was found in the telomere-linked helicase gene (TLH1) family, suggesting some telomere regions may be more unstable than the rest of the genome. Taken together, our results suggest that phenotype and genotype of M. oryzae isolates do not noticeably change, at least up to 10 successive generations on a cultural medium and in host plants.

• 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.

• Plant Resources
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• 제7권2호
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• pp.93-103
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• 2004

Genetic background and phylogenetic relationships among 20 Korean wheat cultivars were assessed using microsatellites after amplifying with 13 SSR primer pairs. Average allele number per primer pair was 3.36. Genetic similarities for every pair of cultivars ranged from 0.42 to 0.97, with 0.69 of overall average. Korean cultivars were divided into two major groups based on microsatellite DNA polymorphisms. Group I consisted of relatively old cultivars developed until 1970s, and group II contained the recent cultivars developed during 1980s and 1990s. Amongst old elite cultivars/lines, ‘Yukseung 3’, ‘Norin 12’ and ‘Norin 72’ contributed most to the genetic background of cultivars belonging to group I, and ‘Norin 4’, ‘Norin 12’, ‘Norin 43’ and ‘Norin 72’ to group II, respectively. The phylogenetic relationship of Korean wheat cultivars was in accordance with the genealogical data of each cultivar. The genetic background of each cultivar was assessed from the point of breeding and germplasm management such as variety identification and duplicated accessions for assisting in developing a system for the registration of new variety based on the molecular characterization in future.

• 한국자원식물학회지
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• 제28권6호
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• pp.697-703
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• 2015

Twenty apple germplasm accessions from the Korean Genebank were successfully cryopreserved using two-step freezing to back up genetic resources maintained by field collections. This study examined the morphological and genetic stability of cryopreserved dormant apple buds that were stored in liquid nitrogen, and then rewarmed and regrown. Whole plants were regenerated directly from dormant buds through budding without an intermediary callus phase. The cryopreserved buds produced high levels of shoot formation (76.2-100%), similar to those of noncryopreserved buds (91.3-100%), with no observed differences between cryopreserved and noncryopreserved materials. Three of the twenty cryopreserved apple germplasm accessions were used to assess morphological and genetic stability. No differences in morphological characteristics including shoot length, leaf shape, leaf width/length ratio, and root length were observed between controls (fresh control and noncryopreserved) and cryopreserved plantlets. The genetic stability of regenerants (before and after cryopreservation) was investigated using inter simple sequence repeat (ISSR) markers. The ISSR markers produced 253 bands using four primers, ISSR 810, SSR 835, ISSR 864, and ISSR 899. These markers showed monomorphic banding patterns and revealed no polymorphism between the mother plant and regenerants before and after cryopreservation, suggesting that cryopreservation using two-step freezing does not affect the genetic stability of apple germplasm. These results show that two-step freezing cryopreservation is a practical method for long-term storage of apple germplasms.

• 한국자원식물학회지
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• 제19권1호
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• pp.144-149
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• 2006

본 연구는 나라꽃 무궁화의 아름다움을 나타내는 화색에 미치는 요인 중 토양산도와 무궁화의 화색특성과 생장과의 관계를 조사 연구함으로써 가장 이상적인 색깔을 갖추는 pH 범위를 파악하여 무궁화 화색육종 계획의 기초를 마련하고자 하였다. 토양산도별 생육특성을 조사하고 분석한 결과 홍화랑과 영광 품종은 pH 7에서 엽수가 183.73개와 135.87개로 가장 높게 나타났으며 pH가 증가함에 따라 증가하였다. 토양산도별 4품종의 화색변화를 조사하고 분석한 결과 홍화랑 품종은 pH가 높아짐에 따라 L값은 $17.05{\sim}12.26$로 점점 낮아졌으며 a값은 $16.37{\sim}20.91$로 점점 높게 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.319-319
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• 2022

Dill(Anethum graveolens L.) is a buttercup family, and flowers, leaves, stems, and seeds are all mainly used as spices. This study was carried out to discover and propagate genetic resources for the development of plant-derived medicinal fragrance materials, and to establish a database. In order to investigate the genetic characteristics of dill and to extract natural essential oils, 50 resources were parceled out the genetic resource center, sown, germinated, and then formally cultivated in the test research field. After sowing and propagation of 50 dill resources, the characteristics of each individual such as plant height, the diameter of polychasium during flowering, and the number of small inflorescences were investigated. The flowering period of dill was around May 31 to June 17, and about 10% of the proliferating population flowered around May 31. The plant length of dill was 32-14 lcm, and the length of petiole was 1~16cm, showing an average of 5cm. The color of the stem and leaf color was referred to the RHS Color chart, and the colors were classified as 44S, 19 V, and 75DI. Uses as many resources as possible with 35 resources equivalent to 19V. Inflorescences are lateral and opposite, polychasium inflorescences are somewhat flat at the upper part and have a diameter of 4.5~20cm, and divergent inflorescences are irradiated with 5~86 multiple flowers. The number of pedicels is 16-74, and the length of the pedicel is 1-18cm spread sideways or the length is different from each other.

• Plant Resources
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• 제4권3호
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• pp.121-129
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• 2001

Intraspecific genetic diversity of sixteen accessions of Mogolian Alliums including fifteen species was investigated using randomly amplified polymorphic DNA (RAPD) analysis. Twenty three out of forty primers revealed scorable polymorphism. A total of 440 RAPD markers were generated on the 16 accessions of Mongolian Alliums. Among 440 RAPDs assayed, 439 were polymorphic with a mean polymorphic rate of 99.7%. Unweighted pair-group method using an arithmetic average (UPGMA) cluster analysis using RAPD data separated the 16 Allium accessions into two broad groups at similarity index 0.70. The clustering of the species was closely related with previous classification between A. altaicum and A. fistulosum. In addition, a high genetic similarity was showed between A. cepa and A. tagar.

• 한국자원식물학회지
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• 제23권3호
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• pp.214-222
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• 2010

Many research results have indicated that many kinds of useful ingredients are rich in buckwheat, which have high nutritional values and medicinal properties, so, buckwheat has been cultivated around Asia and Europe. In this paper, genetic diversity of common and tartary buckwheat germplasms were studied based on morphological and molecular markers in order to provide useful information for conservation and utilization of buckwheat genetic resources. The length, width, thick, value and weight of the seed of the common and tartary buckwheat were measured and analyzed by the statistics methods. The result has shown that there are morphological variation both in common buckwheat and tartary buckwheat seeds collected from different regions. It also has shown that the morphological variation of tartary seeds was significantly correlated to geographical regions. The nuclear ribosomal internal transcribed spacers (ITS) of the tartary buckwheat collected from different countries were cloned, sequenced and statistically analyzed. The data showed that ITS sequences were informative to analyze the phylogeny of the tartary buckwheat and the data also showed that the genetic distances varied among different tartary buckwheat seeds collected from different countries.

• Journal of Plant Biotechnology
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• 제3권1호
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• pp.33-38
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• 2001

Protoplasts isolated from inbred lines of Brassica oleracea L. var capitata (cabbage) and Brassica campestris L. ssp. pekinensis (Chinese cabbage) were fused by PEG-mediated method, and somatic hybrid cells were differentiated into plants. for the identification of somatic hybrid plants, ploidy level, plant morphology, and cytological analysis were performed. All of the regenerated plants derived from fused protoplasts were shown to be 2X-4X, or higher ploidy level, presumably due to somatic hybridization or chromosome doubling. The morphology of leaves, petioles, and flowers showed an intermediate phenotype between Chinese cabbage and cabbage. Chromosome numbers in these somatic hybrids ranged mostly from 33 to 38. According to Genomic in situ hybridization (GISH) pattern, signals from both fusion parents of B.campestris or B.oleracea were detected in different colors when chromosomes of putative somatic hybrids were observed.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 춘계학술대회 및 국제심포지움 초록집
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• pp.79-79
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• 2005