• 한국식물병리학회지
• /
• 제14권4호
• /
• pp.325-330
• /
• 1998

On the basis of the fact that the pycnidiospore of Botryosphaeria dothidea, the causal fungus of apple white rot is a typical water borne spore, a method for quantitative analysis of pycnidiospore dispersal from the warts produced on the diseased apple tree stem was developed. The warts on which cracks developed either on or around them were cut off at the base, and shaked in the water for 4hours at 2$0^{\circ}C$, in which condition the maximum number of spores were released. The volume of shaking solution was calculated as 1 ml per one wart. At the end of shaking, Trio, a household detergent was added to the shaking solution to the concentration of 0.1%, and shaked for additional 10 minutes at 35$^{\circ}C$ to take off the spores attached on the glass ware. One milliliter of the spore suspension thus prepared were passed through transparent membrane filter (pore size : 3.0 ${\mu}{\textrm}{m}$), and the spores attached on the filter were counted under a microscope ($\times$200) after staining them with lactophenol supplemented with aniline blue. The results thus obtained were statistically consistent when at least 30 warts were used simultaneously in single shaking. This method can be applicable in the elucidation of ecology of sporulation and spore dispersal, and also in the screening of the sporulation inhibitor which can be used in the control of the disease by reducing the inoculum density.

• 한국산림과학회지
• /
• 제96권6호
• /
• pp.633-638
• /
• 2007

보리밥나무(Elaeagnus macrophylla)는 해안 인접지의 척박한 토양에서 생육하는 상록성 질소고정 식물로서, 열매의 결실기는 조류의 봄철 이동시기와 일치한다. 보리밥나무의 열매를 이용하는 조류를 파악하고 이들이 보리밥나무의 종자 산포와 발아에 미치는 영향을 밝히기 위하여 2007년 3월부터 4월까지 이동성 조류의 중간 기착지인 전남 선안군 홍도에서 조류 조사 및 종자 발아실험을 실시하였다. 그 결과 찌르레기(Sturnus cineraceus), 직박구리(Hypsipetes amaurotis), 개똥지빠귀(Turdus naumanni) 등 8종의 조류가 보리밥나무 열매를 섭식하였으며, 조류에 의해 소화된 종자는 자연 상태로 파종된 열매에 비해 발아시기가 단축되고 발아율도 높아진 것으로 나타났다. 또 열매를 주로 이용한 찌르레기류의 행동권 분석을 통해 보리밥나무 종자의 잠재적인 산포 범위는 6.9 ha에 이를 수 있는 것으로 예측되었다. 따라서 보리밥나무는 이동시기의 조류에게 중요한 먹이자원을 제공하고, 조류는 보리밥나무 종자의 산포자로서 새로운 지역으로 정착할 수 있는 기회를 주는 것으로 판단된다. 이와 같은 개척자 식물과 종자 산포자간의 상호작용은 척박한 해안 및 도서지역의 훼손된 상록활엽수림과 난대림 생태계의 자연 복원에 활용될 수 있을 것으로 기대된다.

• 환경생물
• /
• 제32권1호
• /
• pp.88-94
• /
• 2014

종의 장거리 산포는 집단의 확산과 집단간 개체의 흐름에 중요한 역할을 한다. 본 연구는 독도에서 발견된 식물을 형태학적 특징과 핵 및 엽록체 DNA의 분자마커를 이용하여 종을 식별한 결과, 참빗살나무 (노박덩굴과)로 확인되었다. 얕은 토양층과 험준한 지형 등 입지적으로 열악한 대양섬인 독도에서 목본의 분포는 의미있는 결과이며, 향후 외부유입종의 지속적인 모니터링이 요구된다.

• Ocean and Polar Research
• /
• 제26권1호
• /
• pp.23-32
• /
• 2004

As a baseline survey for long-term monitoring on environmental change around the Antarctic King Sejong Station, distribution pattern of Deschampsia antarctica Desv., a flowering plant newly colonized were investigated qualitatively and quantitatively in both austral summer 2002 and 2003. Dispersal of the seeds and vegetative leaves by skuas might lead to the colonization into this area from neighbors in Maxwell Bay. The pioneer populations were observed around ponds and a stream of the Sejong Point in January 2002, and the maximum dispersal area was four times expanded after a year. Most of the populations were formed on the stable and well-drained substrate, which consisted of moss carpet of Sanionia georgico-uncinata (65%) and pebbles (25%), while only a few young individuals were observed on the unstable and watertight silt-sandy area. Especially, S. georgico-uncinata was being effectively utilized as their primary substrate with the soft, coarse and water-contained leaves. Also the perennial mature plants of D. antarctica were mainly formed on the moss carpet rather than pebbles. A few individuals were grown on other mosses of Polytrichastrum alpinum, Bryum pseudotriquetrum, Pohlia cruda, and Conostomum magellanicum and on a liverwort of Cephaloziella varians. We expect that dispersal of D. antarctica and the following succession to grass field will be countinuously and dynamically proceeded in this area, with the characteristics of ecological niche against the initial moss populations, on the similar continuity of environmental conditions. The continuous observations are needed with establishment of database on environmental change of micro-habitats, e.g. the water content and nutrients of soil and the underground temperature and permafrost.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2005년도 추계학술발표회 요지
• /
• pp.270-271
• /
• 2005

• The Korean Journal of Ecology
• /
• 제21권5_1호
• /
• pp.457.2-486
• /
• 1998

Ecological success of introduced species is frequently attributed to the reproductive characters of those species. We examined the relationship between both flowering season and plant size and reproductive characters in two introduced species of Taraxacum, e.g., T. officinale and T.laevigatum. Seventy six plants of T. officinale and 23 plants of T. laevigatum were randomly tagged from a population at the sungshin Women's University in April of 1997. The size and number of vegetative characters such as rosette diameter, leaf number, and the largest leaf length and width were measured for each plant at the onset of flowering. The infructescence was collected continually from each plant before seed dispersal from April to August of 1997. The number of infructescence per plant, and seed number and total seed weight per infructescence were measured. Mean individual seed weight per infructescence was also obtained. T. officinale possessed larger sized, but smaller number of, leaves than T. laevigatum, thereby resulting in no significant difference in total leaf area. There was a trend that vegetatively larger plants in both of these species produced reproductive characters larger in size or greater in number, except for seed number and total seed weight per infructescence in T. laevigatum. All reproductive characters examined in T. officinale decreased toward the end of flowering season. In T. laevigatum, infructescence number per plant also declined during a flowering season: however, mean seed number per infructescence increaed toward the end of flowering season with no significant seasonal change in the total seed weight per infructescence. T. officinale produced on average about twice as many seeds per plant as T. laevigatum during a growing season. These two Taraxacum species produced quite small seeds in size compared to the endemic species, exhibiting a far better dispersal ability of introduced species. These data demonstrate that most reproductive characters decline in size and number in both species during a long flowering period, but the two species appear to employ different strategies to achieve reproductive success in disturbed habitats.

• Journal of Ecology and Environment
• /
• 제33권1호
• /
• pp.19-22
• /
• 2010

Migratory birds, by crossing significant ecological barriers, carry and may subsequently introduce exotic seeds into new ecological zones during period of migration. The study of epizoochory, which includes seed dispersal by adhesion to bird feathers, has been relatively neglected compared to the study of seed dispersal by frugivores. To determine whether exotic seeds are being imported to stopover islands by migrating birds, and to estimate the quantity of seeds of exotic species being introduced, we examined migratory birds that were captured in mist nets for attached exotic plant diaspores in 2008 and 2009 on Hongdo Island, Korea. From a total of 3,947 birds examined, we found exotic seeds of Japanese Chaff Flowers (Achyranthes japonica) attached to three species of migratory birds (0.08%; Eurasian Bittern Botaurus stellaris, Swinhoe's Rail Coturnicops exquisitus and Oriental Turtle Dove Streptopelia orientalis). Despite the low occurrence of A. japonica seeds on the external parts of birds, the results suggest that migratory birds may be potential dispersing agents for A. japonica, a species that is currently threatening native ecosystems on many islands in Korea.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제6권2호
• /
• pp.163-169
• /
• 2003

Studies were conducted on the effect of pruning time, host age, conidial dispersal and weather parameters on the incidence and severity of mulberry leaf spot (Myrothecium roridum). The disease severity (%) increased with increase in shoot age irrespective of pruning date. Maximum disease severity was observed in plants pruned during first week of April and minimum disease severity in plants pruned during first week of March. Significant (P ＜ 0.01) influence of date of pruning, shoot age and their interaction was observed on severity of the disease. Apparent infection rate (r) was significantly higher during the plant growth period from day 48 to day 55. Average apparent yale was higher in plants pruned during first week of April and least in plants pruned during first week of July. The disease infection was negatively correlated to distance from the inoculum source. Leaf spot severity (%) was influenced by weather parameters. Multiple regression analysis revealed contribution of various combinations of weather parameters on the disease severity. Linear prediction model $(Y ＝ －81.803＋1.176x_2＋0.765x_3) with significant $R^2$ was developed for prediction of the disease under natural epiphytotic condition.

• The Korean Journal of Ecology
• /
• 제25권1호
• /
• pp.1-7
• /
• 2002

The ecological background of a restoration project is complex and difficult to betermine without experimentation. A useful context for experiments is the well-studied process of natural succession, because the factors that drive or inhibit succession are also at work during reclamation (a form of primary succession) and restoration (which often resembles secondary succession). Using experimental studies on urban wasteland reclamation, we have tested for factors that stimulate or inhibit succession during early phases of woodland development in the Northeastern United states. The emphasis has been on mutualisms (seed dispersal, pollination, and mycorrhizae) and microsite limitations in the recruitment, growth, and reproduction of woody plants. Using plantings of seeds, seedlings, and clusters of reproductively mature plants on abandoned landfills, we have observed that (1) soil microsite deficiencies lead to very poor germination (<0.1$\%$) and seedling survival (<0.01$\%$) of most native species; (2) seed dispersal by birds is a significant and reliable source of woody plant recruitment; however (3) proximity effects are strong, with most (up to 95$\%$) of seed rain falling in the vicinity of planted clusters that are closest to putative seed sources; and (4) remnant natural woodlands are critical components of the recruitment process. To emphasize the last point, in one case, we found that the destruction of approximately 50$\%$ of nearby natural woodland vegetation led to a commensurate decline in seed rain. In another case, we found that the species richness of recruits was strictly limited by the species composition of nearby source plant communities, with no evidence of community enrichment by long distance dispersal over 5 years. We conclude from these results that the size and proximity of remnant natural populations are critical considerations when planning reclamation and restoration programs that rely on natural successional processes.

• The Plant Pathology Journal
• /
• 제15권6호
• /
• pp.330-334
• /
• 1999

Applying the method of quantitative analysis of pycnidiospore from the detached warts produced by the infection of Botryosphaeria dothidea on apple stems, repeated productivity of spores within the detached warts, variations in the amount of spores within the detached warts, variations in the amount of spores by the length of induction time for sporulation, and the effects of temperature and moisture on the sporulation were investigated. In addition to these experiment, the changes in the state of spores within the pycnidia contained in the warts accompanied by the induction of sporulation and dispersal of spores were also investigated. When detached warts were kept in moist conditions, the sporulation and discharge of spores were also investigated. When detached warts were kept in moist conditions, the sporulation and discharge of spores could be repeated several times, and the amount of spores were almost constant after each repeat of sporulation induction and dispersal of spores in a given period. The fact that the pycnidia filled with spores were observed at considerable rates within the warts which were subjected to the shaking in the water to release spores indicated that the spores might never be released until the pycnidia were fully matured. From the high rate of empty pycnidia even in the warts which were kept in moist conditions for induction of sporulation, the pycnidiospores might be produced through the development of new pycnidia. A considerable amount of pycnidiospores were produced at $5^{\circ}$, and the sporulation was accelerated with the rise of temperature until $35^{\circ}$. When the warts were supplied with sufficient moisture, sporulation was further accelerated. The results obtained in these experiment will be applied in developing the method for assessing the inhibitory efficacies of fungicides on the sporulation of this fungus, with which a new control measure would be developed.