• Korean Journal of Plant Resources
• /
• v.30 no.3
• /
• pp.287-297
• /
• 2017

Little millet (Panicum sumatrense) is well known for its salt and drought stress tolerance and high nutritional value, but very limited knowledge of genetic variation and genomic information is available. In this study, a total of 779 primer pairs were designed from the 22,961 EST sequences of switchgrass (Pancium virgatum), of which 48 EST-SSR markers were developed based on the trials of transferability of these primers in little millet. The EST-SSR amplicons showed reproducible single band polymorphism and produced a total of 160 alleles with an average of 3.3 alleles per locus in 37 accessions of little millet. The average values of expected and observed heterozygosities were 0.266 and 0.123, respectively. The polymorphic information content (PIC) values were observed in range of 0.026 to 0.549 with an average of 0.240. The genetic relatedness among the little millet accessions was evaluated by neighbor-joining dendrogram, which grouped all accessions into two distinct groups. The validation thus demonstrated the utility of the switchgrass EST-SSR markers in assessing genomic relationships in little millet. The findings from this study could be useful for designing strategies for the identification of diverse germplasm for conservation and future molecular breeding programs for little millet.

• Korean Journal of Plant Resources
• /
• v.24 no.6
• /
• pp.675-687
• /
• 2011

Mulberries have importance in the sericulture industry as food for Bombyx mori, silkworm reared for its silk. Korean Morus alba have many cultivars and, for the protection of these cultivars and for utilization in plant-breeding programs, genetic information and the diversity among cultivars are essential. This study with 14 mulberry genotypes was undertaken using RAPD and ISSR fingerprinting to discover the genetic divergences between cultivars. Polymorphism rate among the cultivars produced by RAPD primer was found to be 64.48% and 66.29% relative to ISSR primer. The genetic relationships among the cultivars were identified using a dendrogram constructed with the UPGMA clustering method. Nei's method was used to calculate the genetic dissimilarity coefficients between each pair of genotypes, and the highest dissimilarity coefficient of 0.246 was exhibited between Suwon and Hwanggum cultivars. To determine the efficiency of each primer, a polymorphic index was calculated, and the robustness of the dendrogram was checked using cophenetic correlation coefficient. The results of this study can be utilized for the improvement of mulberry varieties in plant-breeding programs.

• Journal of Mushroom
• /
• v.10 no.2
• /
• pp.93-99
• /
• 2012

This study was carried to identify a correct species and asses genetic diversity within the same species of Grifola spp. preserved in Division of applied Microbiology. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Grifola spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that four strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Grifola clustered into one group, most of which correlated with species-groups identified by RAPD method. Eight isolates included strain GM01 showed high similarity with Grifola frondosa. All isolates were collected in the Japan(GM01, GM02, GM03) was identified as Grifola frondosa and isolates of the China(GM05, GM06, GM08) was identified as Bjerkandera fumosa, Grifola frondosa and Dichomitus squalens, respectively. RAPD analysis of genetic polymorphisms of genus Grifola showed a very different band patterns on the isolat. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 4 isolates of Grifola spp. may be need to reclassify or eliminate from preserved catalogue.

• Journal of Mushroom
• /
• v.9 no.1
• /
• pp.27-33
• /
• 2011

This study was carried to identify a correct species and asses genetic diversity within the same species of Trametes spp. preserved in Division of applied Microbiology The morphological and cultural characteristics of preserved strains were observed through microscope and investigated on PDA, respectively. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Trametes spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that five strains were different species and six strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Trametes clustered into four distinct group, most of which correlated with species-groups identified by RAPD method. Seven isolates included TM 01 strain showed high similarity with Trametes versicolr, TM 07 and TM 10 high similarity with Trametes gibbosa, and TM 05 high similarity with Trametes elegans. But isolates collected in the United States was identified as T. junipericola. T. gibbosa and T. versicolor by RAPD analysis of genetic polymorphisms showed a very different band patterns and these strains showed different band patterns on areas. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 11 isolates of Trametes spp. may be need to reclassify or eliminate from preserved catalogue.

• Journal of Mushroom
• /
• v.10 no.1
• /
• pp.37-43
• /
• 2012

This study was carried to identify a correct species and asses genetic diversity within the same species of Polyporus spp. preserved in Division of applied Microbiology. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Polyporus spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that three strains were different species and four strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Polyporus clustered into five distinct group, most of which correlated with species-groups identified by RAPD method. Four isolates included strain PM02 showed high similarity with P. arcularius, four isolates included strain PM03 high similarity with P. alveolaris, three isolates included strain PM01 high similarity with P. tuberaster, and PM 06 and PM04 high similarity with P. brumalis and P. squamossus. Isolates were collected in the United States(PM10, PM11) was identified as P. alveolarius and P. arcularius. RAPD analysis of genetic polymorphisms of genus Polyporus showed a very different band patterns. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 6 isolates of Polyporus spp. may be need to reclassify or eliminate from preserved catalogue.

• Journal of Forest and Environmental Science
• /
• v.40 no.2
• /
• pp.111-117
• /
• 2024

An evaluation was carried out on variability in morphology of fruits and seeds (number and weight) of Tetrapleura tetraptera (Schumach. and Thonn.) Taub. from different populations across its distribution range in Nigeria. Bulk fruit samples were collected and examined for variations in morphological characters. Differences in morphological character of fruits and seeds among the populations were determined using analysis of variance at 5% level of probability. The relationships among morphological characters were determined using Pearson correlation coefficient (r). Significant variations (p<0.05) existed among T. tetraptera populations for all the evaluated characters: fruit length, fruit width, number of seeds per fruit and seed weight. A positive significant strong correlation (r=0.96) was found between seed weight and number of seeds per fruit, while no correlation existed between fruit length, width and number of seeds. Seed weight was positively correlated with minimum altitude (r=0.97) and maximum altitude (r=0.99) of seed populations. Number of seeds was also significantly correlated with maximum altitude (r=0.965). There was no significant correlation between geo-climatic variables and fruit dimensions (length and width). Observed variations in morphological traits within and across populations of T. tetraptera may be used as proxy to estimate genetic diversity and selection of superior trees for improved productivity.

• The Plant Pathology Journal
• /
• v.15 no.4
• /
• pp.228-235
• /
• 1999

Genetic diversity of ninety-five Korean isolates of Phytophthora was investigated on the basis of PCR-RFLP of ribosomal DNA. The isolates were previously identified as following fifteen species by mycological and cultural characteristics; P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamoni, P. citricola, P. citrophthora, P. cryptogea, P. drechsleri, P. erythroseptica, P. infestans, P. megasperma, P. nicotianae, P. palmivora and P. sojae. The regions of small subunit (SSU) and internal transcribed spacer (ITS) of rDNA were amplified with primer pair, NS1 and ITS4, by polymerase chain reaction (PCR) and digested with nine restriction enzymes. P. boehmeriae, P. cactorum, P. cambivora, P. capsici, P. cinnamomi, P. citricola, P. citrphthora, P. infestans, P. nicotianae and P. palmivora showed specific band patterns for each species. However, P. sojae and P. erythroseptica presented identical band patterns and P. cryptogea, P. drechsleri and P. megasperma were divided into six groups, which were not compatible with delineation of the species. A group originated from cucurbits showed distinct band patterns from other groups, but the other five groups were closely related within 96.0% similarity, forming one complex group. Consequently, Korean isolates of Phytophthora were divided into thirteen genetic groups and each group was readily differentiated by comparing digestion patterns of AvaII, HaeIII, MboI, HhaI and MspI. Therefore, PCR-RFLP of rDNA using the five enzymes can be used to differentiate or identify the Phytophthora species reported in Korea so far.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.2
• /
• pp.423-432
• /
• 2014

Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is applied for solving Combined Economic Emission Dispatch (CEED) problem with valve-point loading of thermal generators. This CEED problem with valve-point loading is a nonlinear, constrained multi-objective optimization problem, with power balance and generator capacity constraints. The valve-point loading introduce ripples in the input-output characteristics of generating units and make the CEED problem as a nonsmooth optimization problem. To validate its effectiveness of NSGA-II, two benchmark test systems, IEEE 30-bus and IEEE 118-bus systems are considered. To compare the Pareto-front obtained using NSGA-II, reference Pareto-front is generated using multiple runs of Real Coded Genetic Algorithm (RCGA) with weighted sum of objectives. Comparison with other optimization techniques showed the superiority of the NSGA-II approach and confirmed its potential for solving the CEED problem. Numerical results show that NSGA-II algorithm can provide Pareto-front in a single run with good diversity and convergence. An approach based on Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) is applied on non-dominated solutions obtained to determine Best Compromise Solution (BCS).

• Animal cells and systems
• /
• v.16 no.2
• /
• pp.145-153
• /
• 2012

The pear psylla, $Cacopsylla$ $pyricola$ (Hemiptera: Psyllidae), is a serious insect pest of commercial pear crops. The species, which resides on pear trees throughout its life cycle, is rapidly spreading in some regions of the world. The population genetic structure of the species collected from several pear orchards in Korea was studied to understand the nature of dispersal and field ecology of the species. The 658-bp region of mitochondrial COI gene and the 716-bp long complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA were sequenced. Unlike other previously studied insect pests, the COI-based genetic diversity of the pear psylla was extremely low (maximum sequence divergence of 0.15%). This finding allowed us to conclude that the species may have been introduced in Korea relatively recently. ITS2 sequence-based analyses of phylogeny, population differentiation, gene flow, and hierarchical population structure all concordantly suggested that the pear psylla populations in Korea are neither genetically isolated nor hampered for gene flow. These genetic data are concordant with the dispersal of an overwintering winterform morph outside the non-pear habitat in the fall.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.11
• /
• pp.1680-1687
• /
• 2020

Fungal endophytes are symbiotic microorganisms that are often found in asymptomatic plants. This study describes the genetic diversity of the fungal endophytes isolated from the roots of plants sampled from the west coast of Korea. Five halophytic plant species, Limonium tetragonum, Suaeda australis, Suaeda maritima, Suaeda glauca Bunge, and Phragmites australis, were collected from a salt marsh in Gochang and used to isolate and identify culturable, root-associated endophytic fungi. The fungal internal transcribed spacer (ITS) region ITS1-5.8S-ITS2 was used as the DNA barcode for the classification of these specimens. In total, 156 isolates of the fungal strains were identified and categorized into 23 genera and two phyla (Ascomycota and Basidiomycota), with Dothideomycetes and Sordariomycetes as the predominant classes. The genus Alternaria accounted for the largest number of strains, followed by Cladosporium and Fusarium. The highest diversity index was obtained from the endophytic fungal group associated with the plant P. australis. Waito-C rice seedlings were treated with the fungal culture filtrates to analyze their plant growth-promoting capacity. A bioassay of the Sm-3-7-5 fungal strain isolated from S. maritima confirmed that it had the highest plant growth-promoting capacity. Molecular identification of the Sm-3-7-5 strain revealed that it belongs to Alternaria alternata and is a producer of gibberellins. These findings provided a fundamental basis for understanding the symbiotic interactions between plants and fungi.