• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.444-450
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• 2009

Amplified fragment length polymorphism (AFLP) marker was utilized for evaluation of genetic diversity of 60 pear germplasms. Twenty selective AFLP primer pairs generated a total of 522 polymorphic amplification products. From UPGMA (unweighted pair-group method arithmetic average) cluster analysis by using polymorphic bands, the pear germplasms were divided into four clusters by similarity index of 0.691. The first cluster (I) included European pears belonging to Pyrus communis and wild species such as P. nivalis and P. cordata. The second cluster (II) included Ussurian pea pears belonging to P. betulaefolia and P. fauriei. The third cluster (III) included pea pears belonging to P. calleryana and P. koehnei. Most of germplasms belonging to P. pyrifolia and P. ussuriensis, and interspecific hybrids were included in the fourth (IV) cluster. Therefore pear germplasms originated from East Asia were closely related to P. pyrifolia and P. ussuriensis. Similarity values among the tested pear germplasms ranged from 0.584 to 0.879, and the average similarity value was 0.686.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.790-799
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• 1997

Aegilops genus is known to include the donor species of the Band D genome of the bread wheat(ABD). An effort to establish a better strategy for phylogenetic relationships about Aegilops polyploids by AFLPs(Amplified Fragment Length Polymorphisms) was conducted using the 19 Aegilops sPP. and T. aestivum. The 207 polymorphic bands from the amplified products on the 6% acrylamide denaturing sequencing gels were obtained with the 7 AFLP primer combinations, and used to account for the genetic similarities and cluster analysis using NTSYS program. According to the genome analysis, the $M^h$-genome of Ae. heldreichii was estimated as an intermediate genome between the M-genome of Ae. comosa and N-genome of Ae. uniaristata and supposed to be incorporated in the establishing process of UM-genome as a possible diploid donor. And Ae. ventricosa(DN) was more close to Ae. umbellulata(U) than Ae. squarrosa(D). The close relationship between Ae. squarrosa and T. aestivum was perceived as a diploid donor of D-genome. As for the polyploid species, hexaploid Ae. triaristata was more closely related to Ae. columnaris rather than tetraploid Ae. triaristata. The clustered groups were, basically same to the previous Gihara's sections based on phenotypes and pairing analysis of interspecific hybrids. AFLP was evaluated as an efficient and powerful method in the genome evaluation of closely related species.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.127-142
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• 2024

This study aimed to understand the interrelationships between tree species in plant communities through Plant Social Network (PSN) analysis using a large amount of vegetation data surveyed in an island area belonging to a warm-temperate boreal forest. The Machilus thunbergii, Castanopsis sieboldii, and Ligustrum japonicum, which belong to the canopy layer, Pittosporum tobira and Ardisia japonica, which belong to the shrub layer and Trachelospermum asiaticum and Stauntonia hexaphylla, which belong to the vines, appearing in evergreen broad-leaved climax forest community, showed strong positive association(+) with each other. These tree species had a negative association or no friendly relationship with deciduous broad-leaved species due to the large difference in location environments. Divided into 4 group modularizations in the PSN sociogram, evergreen broad-leaved tree species in Group I and deciduous broad-leaved tree species in Group II showed high centrality and connectivity. It was analyzed that the arrangement of tree species (nodes) and the degree of connection (grouping) of the sociogram can indirectly estimate environmental factors and characteristics of plant communities like DCA. Tree species with high centrality and influence in the PSN included T. asiaticum, Eurya japonica, Lindera obtusiloba, and Styrax japonicus. These tree species are common with a wide range of ecological niches and appear to have the characteristics and survival strategies of opportunistic species that commonly appear in forest gaps and damaged areas. They will play a major role in inter-species interactions and structural and functional changes in plant communities. In the future, long-term research and in-depth discussions are needed to determine how these species actually influence plant community changes through interactions

• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.231-243
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• 2022

Anthropogenic disturbances on freshwater ecosystem are known to degrade biodiversity, especially on fish assemblage. In this study, we have conducted fish surveys to identify impact of a bridge construction on fish assemblages. A total of eight study sites were surveyed in the Danjang and the Dong Stream in southern part of South Korea from June to November in 2021. The fish samplings were carried out five times, using cast-nets(10×10 mm mesh size), scoop-nets(4×4 mm, 5×5 mm mesh size), set-nets (10×10 mm mesh size), and fish traps (3×3 mm mesh size), along with the Stream/River Ecosystem Survey and Health Assessment by the Ministry of Environment of Korea and basic water quality measurement. Also, we applied the species diversity index and length-weight relationship regressions on certain species to identify interspecific growth rate differences in accordance with study sites. As a result, a total of 782 individuals, 23 species and 10 families were collected. The dominant species was Zacco Koreanus and relative abundance was 50.89%. When applying the length-weight relationship regressions on certain species, the 'b' value for Z. Koreanus was lower at the downstream points than at the upstream points of the construction site. In addition, when comparing to the results of the past survey, relative density of demersal fish at the upstream and downstream points decreased from 26% to 1.4%, and from 18% to 6.3%, respectively. In conclusion, it is considered that bridge construction negatively affects the habitat of fishes, especially on demersal fishes. Therefore, appropriate conservation efforts such as installation of silt protector and sand sedimentation pond are needed to alleviate the disturbance in habitat such as occurrence of turbidity and destruction of micro-habitats.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.93-105
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• 2015

This study was performed to analyze genetic relationships of the four major cucurbitaceous crops including watermelon, melon, cucumber, and squash/pumpkin. Among 120 EST-SSR primer sets selected from the International Cucurbit Genomics Initiative (ICuGI) database, PCR was successful for 51 (49.17%) primer sets and 49 (40.8%) primer sets showed polymorphisms among eight Cucurbitaceae accessions. A total of 382 allele-specific PCR bands were produced by 49 EST-SSR primers from 24 Cucurbitaceae accessions and used for analysis of pairwise similarity and dendrogram construction. Assessment of the genetic relationships resulted in similarity indexes ranging from 0.01 to 0.85. In the dendrogram, 24 Cucurbitaceae accessions were classified into two major groups (Clade I and II) and 8 subgroups. Clade I comprised two subgroups, Clade I-1 for watermelon accessions [I-1a and I-1b-2: three wild-type watermelons (Citrullus lanatus var. citroides Mats. & Nakai), I-1b-1: six watermelon cultivars (Citrullus lanatus var. vulgaris S chrad.)] a nd C lade I -2 for melon and cucumber accessions [I-2a-1 : 4 melon cultivars(Cucumis melo var. cantalupensis Naudin.), I-2a-2: oriental melon cultivars (Cucumis melo var. conomon Makino.), and I-2b: five cucumber cultivars (Cucumis sativus L.)]. Squash and pumpkin accessions composed Clade II {II-1: two squash/ pumpkin cultivars [Cucurbita moschata (Duch. ex Lam.)/Duch. & Poir. and Cucurbita maxima Duch.] and II-2: two squash/pumpkin cultivars, Cucurbita pepo L./Cucurbita ficifolia Bouche.}. These results were in accordance with previously reported classification of Cucurbitaceae species, indicating that watermelon EST-SSRs show a high level of marker transferability and should be useful for genetic study in other cucurbit crops.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.39-50
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• 2024

In ecosystems within limited resources, interspecific competition is inevitable, often leading to the competitive exclusion of inferior species. This study aims to provide foundational information for the conservation and restoration management of Microphysogobio rapidus by evaluating species' ecological response to biological factors within its habitat. To understand this relationship, we collected food web organisms from site where M. rapidus coexist with Microphysogobio yaluensis, a specie ecologically similar to M. rapidus, and evaluated the trophic levels (TL), isotopic niche space (INS), and the overlap of INS among fishes within the habitat using stable isotope analysis. Our analysis revealed that the M. rapidus exhibited a higher TL than M. yaluensis, with TL of 2.6 and 2.4, respectively. M. yaluensis exhibited a broad INS, significantly influencing the feeding characteristics of most fish. Conversely, M. rapidus showed a narrow INS and asymmetric feeding relationships with other species, in habitats with high competition levels. This feeding characteristics of M. rapidus indicate that the increase in competitors sharing the similar resources lead to a decrease in available resources and, consequently, is expected to result in a decrease in their density.