소나무재선충의 매개충인 솔수염하늘소(Monochamus alternatus Hope)와 북방수염하늘소(Monochamus saltuarius Gebler) 암수 성충의 더듬이 감각기를 주사전자현미경로 관찰하여 형태적 특성과 분포를 조사하였다. 두 매개충의 암수 성충 더듬이는 자루마디(scape), 팔굽마디(pedicel)와 9개의 채찍마디(flagellum)으로 이루어져 있었다. 더듬이 표면에 있는 감각기의 종류에는 종 간, 암수 간에 차이가 나지 않았으며 Chaetica 3 종류, Trichodea 2 종류, Basiconica 3 종류, Coeloconica 1 종류로 구분되었다. 이 중 Basiconica 3 종류는 모두 후각 수용체, Trichodea는 미각 수용체, 나머지는 기계적 감각기로 추정되었다. 감각기의 더듬이 내 분포를 보면 전체적으로 Chaetica 감각기가 가장 많았다. Basiconica 감각기는 채찍마디에만 존재하였으며 끝으로 갈수록 수가 많아졌다. Trichodea 감각기와 Coeloconica 감각기는 각 마디별로 밀도가 일정하였다.
Most previous studies on dinoflagellates in Korean coastal areas were conducted without morphological descriptions and illustrations of the observed dinoflagellates. This indicates that the species and diversity of dinoflagellates may have been respectively misidentified and underestimated in the past, probably due to cell shrinkage, distortion and loss caused by sample fixation. This study provides information on the morphological observations of four dinoflagellate orders (Prorocentrales, Dinophysiales, Gonyaulacales and Gymnodiniales) from Jangmok Harbour in Jinhae Bay, Korea. The unfixed samples were collected weekly from December 2013 to February 2015. A total of 13 genera and 30 species were identified using light and scanning electron microscopy, although some samples were not clarified at the species level. Harmful dinoflagellates, Prorocentrum donghaiense, Tripos furca, Alexandrium affine, A. fundyense, Akashiwo sanguinea and Cochlodinium polykrikoides, were identified based on the morphological observations. The results also reflect the occurrence and identification of dinoflagellates that had not been previously recorded in Jangmok Harbour.
This study used transmission electron microscopy (TEM) to investigate the micro-morphological features of two formaldehyde to urea (F/U) mole ratio liquid urea-formaldehyde (UF) resins with three hardener levels as a function of the curing time. The micro-morphological features of the liquid UF resins were characterized after different curing times. As a result, the TEM examination revealed the presence of globular/nodular structures in both liquid UF resins, while spherical particles were only visible in the low F/U mole ratio resins. The high F/U mole ratio liquid UF resins also showed extensive particle coalescence after adding the hardener, along with the appearance of complex filamentous networks. When the resins were cured with a higher amount of hardener and longer curing time, the spherical particles disappeared. For the low mole UF resins, the particles tended to coalesce with a higher amount of hardener and longer curing time, although discrete spherical particles were still observed in some regions. This is the first report on the distinct features of the crystal structures in low F/U mole ratio UF resins cured with 5% hardener and after 0.5 h of curing time. In conclusion, the present results indicate that the crystal structures of low F/U mole ratio UF resins are formed during the curing process.
Beauveria bassiana is one of universal insect pathogenic fungi that have been used for biocontrol agent against insect pests. This fungus has also been studied for medicinal use. To meet for commercial use, the artificial production of the fruit body of this fungus has been established by the Mushtech Co in Korea. This study was carried out to define the morphological features of the fruit body of B. bassiana developed through artificial cultivation. For the observation of mycelia growth, B. bassiana was cultured on the Sabouraud Dextrose agar plus Yeast Extract(SDAY), nut-supplemented medium, and Fe ion-supplemented SDAY at 25℃ for 15 days. The variation of colony color was observed between the different media. Strong pigmentation was observed on Fe ion-supplemented SDAY. To investigate morphological characteristics of fruit body, geminating ascospores and vegetative hyphae were observed though light microscopy and scanning microscope. During seven weeks of cultivation period, the development process of apical fertile part of stromata can be separated by the development stage of perithecia. To understand the developing process of fruit body at the transcript level, investigating process of distinct gene expression according to cultural condition and developmental stage was discussed.
Two morphologically different species of Peridinium were frequently observed in natural samples collected monthly from Togyo Reservoir. One was previously identified as P. bipes Stein f. occultatum (Lindem.) Lef. (Ki and Han 2005), the other was remained
국내에 분포하는 대사초절에 속하는 3분류군의 외부형태형질을 분석하고 분자계통학적 연구를 수행하여 이들 간의 유연관계를 밝혔다. 대사초절 내의 기본종인 대사초의 외부형태학 특징을 재검토하여 기존 문헌과의 차이를 파악하였으며, 식물상 문헌 및 표본을 통해 국내 분포도를 작성하였다. 문헌에 언급된 형질들 중에서 잎의 형태는 생육지 조건에 따라 변이가 심하였지만, 지하경 생장 양상, 잎과 과낭의 털의 존재 등은 종수준에서 구분하는데 좋은 형질이었다. 분자계통학적 연구에서 털대사초는 독립된 종으로 처리되는 것을 지지하였다.