• ALGAE
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• 제25권1호
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• pp.27-35
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• 2010

Marked declines in seagrass meadows are increasingly being reported from coasts around Korea and many regions of the world. The transplantation of seagrasses has been attempted to mitigate and control their degradation from a range of anthropogenic factors. In this study, Zostera marina shoots, which were collected from a donor bed in Koje Bay, were transplanted in Jindong Bay in December 2004. In 2008, a comparative investigation of shoot morphology, growth, and reproduction strategy of Z. marina was carried out between the donor and transplant sites to assess their adaptation success. Shoot height, individual shoot weight, and leaf productivity at the transplant site were significantly greater than those at the donor site. However, below-/aboveground tissue ratio was significantly lower at the transplant site compared to the donor site. Z. marina survival was maintained through vegetative reproduction, while peak season for lateral shoot recruitment was late winter for both donor and transplant site populations. However, vegetative reproduction mainly occurred during late winter and spring at the transplant site, whereas lateral shoots were evident across all seasons except late spring in the donor site. More pronounced seasonal variations were found at the transplant site compared to the donor site. These results indicate that Z. marina populations at the two sites possess distinct phenotypic variations induced by different environmental conditions, and Z. marina transplants have adapted well to the new transplant environment.

• 미생물학회지
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• 제40권2호
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• pp.178-182
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• 2004

Saccharomyces cerevisiae의 class I 키틴생합성 효소인 Chsl의 활성측정법을 적용하여 Aspergillus nidulans의 영양균사에서 class I 키틴생합성 효소인 ChsC의 활성측정을 시도하였다. 그 결과, A. nidulans의 class I 키틴생합성효소도 효모류의 경우와 마찬가지로 트립신 처리에 의하여 활성화되는 효소전구체형태(zymogenic form)로 존재함을 알 수 있었다. 그리고 A. nidulans 야생형의 class I 키틴 생합성 효소활성은 트립신 처리에 의하여 6배 가량 증가되었다. 반면, chsC 유전자가 파괴된 돌연변이주는 트립신 처리에 의하여 효소활성이 증가되지 아니하였을 뿐만 아니라, 효소활성의 수준도 트립신을 처리하지 아니한 야생형의 class I 키틴생합성 효소활성과 거의 동일한 수준이었다. 따라서, 트립신을 처리하여 측정한A. nidulans 야생형의 class I 키틴생합성 효소활성 값에서 트립신을 처리하지 아니한 야생형의 class I 키틴생합성 효소활성을 제외한 값이 A. nidulans 야생형의 ChsC 효소활성임을 알았다. 이러한 조건을 토대로 영양균사 생장과정 동안 ChsC의 효소활성을 측정한 결과, chsC 유전자의 발현양상과 유사하게 액체배양상태의 영양균사가 무성분화능을 획득하는 시기로 알려진 시간대에 효소의 활성이 증가하였다. 이러한 결과는 이미 보고된 바와 같이 chs 유전자가 A. nidulans의 영양균사 생장에 관여함을 시사하고 있다.

• Journal of Forest and Environmental Science
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• 제34권6호
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• pp.435-450
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• 2018

Phenological events of four Rhododendron tree species (viz. R. arboreum, R. arboreum ssp. delavayi var. delavayi, R. barbatum and R. kesangiae) was monitored in temperate mixed broad-leaved forests of Arunachal Pradesh, India. Phenological events like flower bud formation, flowering, fruit setting, fruit maturing, seed dispersal, leaf bud formation, leaf flushing, and leaf shedding were recorded. Indices i.e., phenophase sequence index (PSI), active phenophasic period of the species (APS) and index of reproductive/vegetative activity (RVA) were also calculated. Present study revealed that bark consistency, growth form and leaf pattern of the studied species have showed variations among the species. Rhododendron species exhibited the phenological events overlapping with other phenophases. The peak flower bud formation was observed during the winter; R. arboreum ssp. delavayi var. delavayi start flowering from December, while the flowering in rest three species exhibited during February to April. Fruit setting occurred during summer to autumn while fruit maturation revealed peak during November. Leaf bud formation illustrated two peaks in April and May, leaf flushing exhibited peak in June, while leaf shedding peaked during October to November. Active phenophasic period of the species were found 12 months, which revealed that species engage in various phenophase activities throughout the year. Phenophase sequence index ranged between 0.8 to 0.9 (PSI ${\geq}0.6$), signifies that species have a sequential arrangement of phenophases. Index of reproductive/vegetative activity of the species exemplified >1, indicate that the reproductive phenophases were dominance over vegetative phenophases. The study have provided substantial insight on the life cycle events of Rhododendron species and ecological approaches for further scientific study with recent climate change and effective management and conservation.

• Mycobiology
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• 제42권1호
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• pp.1-5
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• 2014

The typical life cycle of filamentous fungi commonly involves asexual sporulation after vegetative growth in response to environmental factors. The production of asexual spores is critical in the life cycle of most filamentous fungi. Normally, conidia are produced from vegetative hyphae (termed mycelia). However, fungal species subjected to stress conditions exhibit an extremely simplified asexual life cycle, in which the conidia that germinate directly generate further conidia, without forming mycelia. This phenomenon has been termed as microcycle conidiation, and to date has been reported in more than 100 fungal species. In this review, first, we present the morphological properties of fungi during microcycle conidiation, and divide microcycle conidiation into four simple categories, even though fungal species exhibit a wide variety of morphological differences during microcycle conidiogenesis. Second, we describe the factors that influence microcycle conidiation in various fungal species, and present recent genetic studies that have identified the genes responsible for this process. Finally, we discuss the biological meaning and application of microcycle conidiation.

• ALGAE
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• 제20권4호
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• pp.295-298
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• 2005

The growth of subaerial microalgae on historic buildings or various cultural properties causes discoloration and physico-chemical deterioration of the surfaces. We collected a subaerial chlorophyte, Chlorella sp., from the stone Standing Buddha statue at Jungwon Miruksazi, which is a national treasure of Korea, and found dormant, thickwalled spores with regular pentagonal ornamentation along with the vegetative Chlorella cells. The morphology of Chlorella resting spores was compared to that of the other green algal resting cells. The ornamented spores and smooth-walled vegetative cells revived in 2 weeks in a liquid freshwater medium and started reproduction by autospores. To our knowledge, the ability of Chlorella to form ornamented dormant spores in drought condition was not previously recorded. The ornamentation of spores would supplement taxonomic characteristics of this genus.

• ALGAE
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• 제18권4호
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• pp.333-339
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• 2003

To establish a cultivation method of Petalonia fascia, seeds and seedlings cultures and growth tests were performed at the Daeri aquafarm in Haeui, Shinan, Jeollanamdo, Korea. Gametes were easily released from the mature plurilocular sporangia. They developed to crustose discoidal stolons and grew to filamentous and discoidal stolons. The indoor seeding was performed by using the 100-150 ${\mu}m$long fragments of stolons on Porphyra nets and the erect thalli developed from the cuttings when the seawater temperatures were 10-15$^{\circ}C$. In the experimental cultivation in the sea, 1-2mm long plantlets were found after 15 days of cultivation; after two months thalli grew to their maximal size of 215-355 mm long blades; after three months the length of thalli began to decrease due to distal disintegration and the plant color changed to yellow and epiphytic diatoms were attached on the thalli, which deteriorated the quality of products. The cultivation of P. fascia by the regeneration of filamentous-discoidal complexes was carried out successfully for the first time in Korea.

• Journal of Forest and Environmental Science
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• 제40권2호
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• pp.141-150
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• 2024

This study aims to develop and commercialize a soundproof wall capable of planting at the urban ecological. The vegetative soundproof wall developed in the study showed highly superb structural test results for sound absorption coefficients and met the quality standards in the sound-absorbing performance test. Its structure is systemized to supply water to soils and plant roots inside the planting basis with rainwater running down the inclined planes near the planting basis in the front of the vegetation panel. It allows for sporadic water supply for about 30 days of drought. The test results show that the plants continued favorable growth and development in leaves, stems, and roots, making the vegetative soundproof plate a product capable of reacting to climate environment changes.

• 한국환경과학회지
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• 제26권5호
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• pp.601-608
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• 2017

The effects of elevated atmospheric $CO_2$ on growth and photosynthesis of soybean (Glycine max Merr.) were investigated to predict its productivity under elevated $CO_2$ levels in the future. Soybean grown for 6 weeks showed significant increase in vegetative growth, based on plant height, leaf characteristics (area, length, and width), and the SPAD-502 chlorophyll meter value (SPAD value) under elevated $CO_2$ conditions ($800{\mu}mol/mol$) compared to ambient $CO_2$ conditions ($400{\mu}mol/mol$). Under elevated $CO_2$ conditions, the photosynthetic rate (A) increased although photosystem II (PS II) photochemical activity ($F_v/F_m$) decreased. The maximum photosynthetic rate ($A_{max}$) was higher under elevated $CO_2$ conditions than under ambient $CO_2$ conditions, whereas the maximum electron transport rate ($J_{max}$) was lower under elevated $CO_2$ conditions compared to ambient $CO_2$ conditions. The optimal temperature for photosynthesis shifted significantly by approximately $3^{\circ}C$ under the elevated $CO_2$ conditions. With the increase in temperature, the photosynthetic rate increased below the optimal temperature (approximately $30^{\circ}C$) and decreased above the optimal temperature, whereas the dark respiration rate ($R_d$) increased continuously regardless of the optimal temperature. The difference in photosynthetic rate between ambient and elevated $CO_2$ conditions was greatest near the optimal temperature. These results indicate that future increases in $CO_2$ will increase productivity by increasing the photosynthetic rate, although it may cause damage to the PS II reaction center as suggested by decreases in $F_v/F_m$, in soybean.

• 한국작물학회지
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• 제48권2호
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• pp.73-80
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• 2003

An experiment was carried out at the Field Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh from March to July, 2001 to investigate the effect of biofertilizers on morpho-physiological characters of okra. The experiment was laid out in a randomized complete block design with four replications. There were nine treatments such as $\textrm{T}_0$ (control), $\textrm{T}_1$ (Azotobacter biofertilizer), $\textrm{T}_2$ (Azospirillum biofertilizer), $\textrm{T}_3$ (Azotobacter+Azospirillum biofertilizers), $\textrm{T}_4$ (Azotobacter+Cowdung 5 ton $\textrm{ha}^{-1}$), $\textrm{T}_5$ (Azospirillum+Cowdung 5 ton $\textrm{ha}^{-1}$), $\textrm{T}_6$(Azotobacter+Azospirillum+Cowdung 5 ton $\textrm{ha}^{-1}$), $\textrm{T}_7$ (Cowdung 5 ton $\textrm{ha}^{-1}$) and $\textrm{T}_8$ (60% Nitrogen). The experimental results revealed that significant variations exist among the treatments regarding morphological characters e.g. plant height, number of leaves/plant, stem base diameter, tap root length, and physiological characters like, root dry weight, leaf area index and crop growth rate. Number of leaves/plant, stem base diameter, root length, root dry weight, leaf area index and crop growth rate were found higher in $\textrm{T}_4$, $\textrm{T}_5$, $\textrm{T}_6$ and $\textrm{T}_8$ than the others. In all the parameters, $\textrm{T}_8$ gave the similar result with biofertilizers in combination with cowdung treatments and $\textrm{T}_7$ showed identical with $\textrm{T}_0$ (control). Biofertilizer treatments had insignificant effect on 1000-seed weight(g). Experimental results mentioned above revealed that morpho-physioligical characters of okra could be modified by the application of biofertilizer+cowdung. However, biofertilizers+Cowdung treatments were comparable to $\textrm{T}_8$(60% Nitrogen) in this study. This suggests that $\textrm{T}_4$ or $\textrm{T}_6$ or $\textrm{T}_5$ were more benificial in environmentally friendly okra cultivation and may be used as an alternative of inorganic nitrogen by saving cost of production and sustaining productivity.

• Mycobiology
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• 제38권2호
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• pp.89-96
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• 2010

This study evaluated the optimal vegetative growth conditions and molecular phylogenetic relationships of eleven strains of Agrocybe cylindracea collected from different ecological regions of Korea, China and Taiwan. The optimal temperature and pH for mycelial growth were observed at $25^{\circ}C$ and 6. Potato dextrose agar and Hennerberg were the favorable media for vegetative growth, whereas glucose tryptone was unfavorable. Dextrin, maltose, and fructose were the most effective carbon sources. The most suitable nitrogen sources were arginine and glycine, whereas methionine, alanine, histidine, and urea were least effective for the mycelial propagation of A. cylindracea. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR. The sequence of ITS2 was more variable than that of ITS1, while the 5.8S sequences were identical. The reciprocal homologies of the ITS sequences ranged from 98 to 100%. The strains were also analyzed by random amplification of polymorphic DNA (RAPD) using 20 arbitrary primers. Fifteen primers efficiently amplified the genomic DNA. The average number of polymorphic bands observed per primer was 3.8. The numbers of amplified bands varied based on the primers and strains, with polymorphic fragments ranging from 0.1 to 2.9 kb. The results of RAPD analysis were similar to the ITS region sequences. The results revealed that RAPD and ITS techniques were well suited for detecting the genetic diversity of all A. cylindracea strains tested.