• Journal of Ecology and Environment
• /
• v.46 no.3
• /
• pp.243-249
• /
• 2022

Background: Mixed breeding herb Viola collina Besser, which produces both chasmogamous and cleistogamous flower, has limited habitats under closed canopy and short and early flowering timing, making it relatively more vulnerable to climate change. To better understand the effect of light and nutrient on the flower formation and vegetative growth of V. collina, a mesocosm experiment was conducted. Two-by-two factorial treatments of two light conditions (100% and 60% of natural light) and two fertilizer treatment conditions (fertilized and not fertilized) were applied in the mesocosm experiment. Results: The number of flowers, including chamogamous and cleistogamous flowers, was highest (5.65/pot) under 60% light and fertilized condition and lowest (1.41/pot) under 100% light and not-fertilized condition. However, above ground vegetative growth was highest (2.89 g/pot) under 100% light and fertilized condition and lowest (2.38 g/pot) under 60% light and not-fertilized condition. Above ground biomass to belowground biomass ratio was highest (1.50) under 60% light and fertilized condition and lowest (1.26) under 100% light and fertilized condition. Conclusions: This study showed that high light and nutrient are responsible for the vegetative growth, though the effect of fertilizer was reduced due to allocation and retainment of nutrients. In addition, the low light is necessary to make flowers, especially chasmogamous flowers.

• Korean Journal of Environment and Ecology
• /
• v.35 no.1
• /
• pp.48-67
• /
• 2021

Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

• Korean Journal of Plant Taxonomy
• /
• v.49 no.2
• /
• pp.140-144
• /
• 2019

A new taxon, Viola ramiflora K. O. Yoo (Violaceae), from Jeju-do is described and illustrated. V. ramiflora shares several characteristics (pale purple flowers; triangular-ovate, ovate, or oblong leaf blades; winged petioles) with the related species V. hirtipes, V. japonica, V. phalacrocarpa, and V. seoulensis. However, this new species has branched cleistogamous and chasmogamous peduncles and oblong-ovate cleistogamous bracteoles.

• Korean Journal of Plant Taxonomy
• /
• v.52 no.4
• /
• pp.226-234
• /
• 2022

The study aims are to examine the characteristics of artificial and natural hybrids between Viola albida var. albida (= albida, from below) and V. albida var. chaerophylloides (= chaerophylloides, from below), and to confirm if hybrids could be fertile and make populations in their native habitats. The 1st filial (= F₁, from below) leaf shape produced by artificial crossing between albida and chaerophylloides was the same as that of V. albida var. takahashii (= takahashii, from below), and F₁ bore also both chasmogamous and cleistogamous flowers. F₁ seed number was 9.6 per cleistogamous pods, which was remarkably less than the average of 38.2 for albida and chaerophylloides, but the germination rate was all similar. The leaf type of self-crossed 2nd offsprings (= F₂, from below) showed all leaf types found in the Viola albida complex, but the ratio of chaerophylloides leaf type was relatively low. Individuals whose F₂ leaf type was restored to albida produced an average of 31.4 seeds per capsule, meaning that fertility was restored. On the other hand, individuals of F₂ takahashii leaf type come to fruition a low average of 10.4 seeds per capsule, which is similar to that of takahashii. The results of crossbreeding experiment, where is their native habitats, were similar to that of laboratory. Both albida and chaerophylloids in Mt. Bulmyeong distribute extensively, but takahashii make a small population only in places where albida and chaerophylloides grow together. Summarizing the above results is suggesting that the speciation of takahashii was done by hybrid between albida and chaerophylloides, and these have been maintained with relatively small population by cleistogamous capsules.

• Korean Journal of Environment and Ecology
• /
• v.33 no.4
• /
• pp.422-439
• /
• 2019

The rear edge population is considered to have low genetic diversity and high risk of extinction according to a highly isolated distribution. However, the rear edge population is observed to have persisted for an extended period despite the low genetic diversity. As such, it is necessary to understand the ecological process involved in the persistence of the population. Viola mirabilis L. in Korea is considered the rear edge population from the perspective of the worldwide distribution. We surveyed the distribution range of V. mirabilis, which shows the isolated distribution in the central area of Korea, to find out the factors of its persistence. Next, we investigated and accessed the vegetational pattern of habitats, soil environment, phenology, self-compatibility, population structure, and extinction risk factors observed in the distribution area. V. mirabilis was distributed in the understory of the deciduous forest, planted forest of the deciduous conifer and deciduous broad-leaved trees, shrubland, and grassland in the limestone area. We also observed the re-establishment of seedlings in the population, and most of them showed a stable population structure. For chasmogamous flowers, the visit by pollinators has a significantly positive relationship with the production of fruits. However, we found that the production of the cleistogamous flowers was more numerous in all studied populations and that only the cleistogamous flowers were produced despite a more substantial plant size in some populations. The plant size was more related to the production of the cleistogamous flowers than that of the chasmogamous flowers. Accordingly, the cleistogamous flowers significantly contributed to seedling recruitment in the population. We found that the production of the chasmogamous flowers and the cleistogamous flowers did not have a correlation with the factors of the soil analysis except for phosphoric acid. V. mirabilis showed the self-incompatibility characteristics most likely due to the production capability of the cleistogamous flowers. Potential extinction risk factors observed in the distribution area was included the development of limestone mine, the expansion of agricultural fields, and the construction of houses. Although V. mirabilis showed an isolated distribution in the limestone area in the Korean peninsula, it showed a diverse distribution in a wide habitat environment ranging from the grassland to the understory of the trees with relatively low canopy closure rate. Moreover, we concluded that the persistence of the population was possible if we can maintain the current state of multiple populations and stable population structure.

• Korean Journal of Environmental Biology
• /
• v.27 no.3
• /
• pp.266-271
• /
• 2009

This study was about three genus of Viola: V. rossii, V. japonica, and V. dissecta var. chaerophylloides which can live together under a deciduous forest canopy. The aim of the study was to directly compare reproductive characteristics of the three species under the same environmental condition. By taking a census of the morphologically different flowers, the results indicate that all three species opened chasmogamous flowers before the canopy of forest closed, but continuously opened cleistogamous flowers after the canopy closed. Numbers of seeds in a capsule followed an ascending order from V. rossii to V. japonica. Mass of seeds followed a descending order from V. rossii to V. japonica. Both results had statistical significance. In terms of characteristics of seed production, V. rossii has been adapted more than V. japonica, and V. dissecta var. chaerophylloides under the deciduous forest.

• Journal of Ecology and Environment
• /
• v.40 no.2
• /
• pp.89-106
• /
• 2016

Many plant species have two modes of reproduction: sexual and asexual. Both modes of reproduction have often been viewed as adaptations to temporally or spatially variable environments. The plant should adjust partitioning to match changes in the estimated success of the two reproductive modes. Perennial plants showed that favorable habitats in soil nutrients or water content tend to promote clonal growth over sexual reproduction. In contrast, under high light-quantity conditions, clonal plants tend to allocate more biomass to sexual reproduction and less to clonal propagation. On the other hand, plants with chasmogamous and cleistogamous flowers provides with a greater tendency of the opportunity to ensure some seed set in any stressful environmental conditions such as low light, low soil nutrients, or low soil moisture. It is considered that vegetative reproduction has high competitive ability and is the major means to expand established population of perennial plants, whereas cleistogamous reproduction is insurance to persist in stressful sites due to being strong. Chasmogamous reproduction mainly enhances established and new population. Therefore, the functions of sexual and asexual propagules of perennial or annual plants differ from each other. These traits of propagule thus determine its success at a particular region of any environmental gradients. Eventually, if environmental resources or stress levels change in either space or time, species composition will probably also change. The reason based on which the plants differ with respect to favored reproduction modes in each environmental condition, may be involved in their specific realized niche.

• Korean Journal of Plant Taxonomy
• /
• v.38 no.4
• /
• pp.547-555
• /
• 2008

Two naturalized plants of Lespedeza from Korea are reported. L. lichiyuniae T. Nemoto, H. Ohashi & T. Itoh is similar to L. cuneata (Dum. Cours.) G. Don. and L. juncea (L. .f.) Pers. in morphology, but the species differs from them by pink or purple flowers and the under surface of leaflets and cleistogamous pods with densely hairs. L. davidii Franchet is distinguished by distinctly large leaflets from the other Korean Lespedeza and by plants covered with densely tomentose hairs from the Korean species of subgenus Macrolespedeza. In Korea two plants are found on the parks or roads prepared recently.

• Korean Journal of Plant Taxonomy
• /
• v.41 no.1
• /
• pp.58-65
• /
• 2011

Commelina benghalensis L. and Commelina diffusa Burm. f. belonging to Commelinaceae, two species previously unrecorded as Korean flora, were collected in the lowlands of Jeju Island in Korea. Commelina benghalensis of the two species is different from others of Commelinaceae in Korea by having funnelform spathes fused at the proximal margin of involucral bracts and cleistogamous flowers. In addition, Commelina diffusa differ from others by having a three-valve capsule and lanceolate and a base cordate or rounded spathelike involucral bracts. The somatic chromosome number of Commelina benghalensis was 2n = 2x = 22 and the sizes of chromosomes were very small, ranging from 1.25 to 2.70 ${\mu}m$. However, the Commelina diffusa chromosome number exceeded 2n = ca. 100, and a precise count could not be obtained. These species are known to be distributed in tropical and subtropical regions of Asia and Africa below the latitude of Jeju Island of Korea.