• Research in Plant Disease
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• v.14 no.2
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• pp.122-126
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• 2008

A stem and leaf rot disease of English ivy(Hedera helix) was found in the flower market, Jeonju, Chonbuk province, Korea in July 2007. A Phytophthora species was isolated from the diseased part of the plant. Based on the mycological properties and pathogenesis the isolate was identified as Phytophthora nicotianae. The fungus produce ovoid sporangium which was ovoid to spherical which is noncaducous, papillate and averaged $35.4{\times}25.2{\mu}m$ in dimension. Chlamydospores were abundantly produced on agar media and sized about 28.5 ${\mu}m$ in diameter. The fungus was heterothallic and A1 mating type. Oospores were measured 23.3 ${\mu}m$ in size. Optimum temperature for growth of the fungus was 25 to $30^{\circ}C$. Up to our knowledge, this is the first report demonstrating the stem rot on English ivy caused by P. nicotianae in Korea.

• Korean Journal of Plant Resources
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• v.8 no.1
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• pp.89-94
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• 1995

The physiological variation and major characteristics of the collected hemp from Mokpo and Suwon region are studied for the basic materials of hemp dioecism's developmental rate adjustment and the physiological function. The results ate following. Female's flowering date in Aug., 10, and male’s in July, 26. In sex ratio, The collected hemp from Mokpo is $47{\sim}53%$ and Suwon in $49{\sim}51%$. The correlation between many other charaoters and sex ratio Show a negative correlation in male. Flowering date, stem diameter, fresh stem yield and hemp skin yield show a psitive correlation. Fiber leght and hemp skin yield show a negative correlation.

• Research in Plant Disease
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• v.10 no.1
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• pp.17-20
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• 2004

A disease causing blights on leaves, stems, flowers, and pods of Vinca (Catharanthus roseus L.) was occurred in Aug. 2003 in Chengdo Peach Experiment Station. A species of Phytophthora was isolated from the diseased tissues. The causal fungus was identified as Phytophthora nicotianae on the basis of mycological characteristics and pathogenicity. Sporangia were ovoid to spherical, noncaducous, prominently papillate and averaged 38.0${\times}$31.0 ${\mu}{\textrm}{m}$ in dimension. Chlamydospores were abundantly produced on agar media and sized about 30.5 fm in diameter, The fungus was heterothallic and Al mating type. Oospores were measured 23.1 ${\mu}{\textrm}{m}$ in size. Optimum temperature for growth of the fungus was 25 to 3$0^{\circ}C$. This is the first report of occurrence of foliage blight of Vinca caused by P. nicotianae in Korea.

• Research in Plant Disease
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• v.11 no.1
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• pp.72-76
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• 2005

In 2002 and 2003, Phytophthora blight on Daphne odora occurred in fields at Waryong Mountain, Sacheon city, Korea. The disease usually initiated on the root and crown of the plant. Crown lesions began with light brown as water-soaking. Infection rate of the disease reached up to 60% in a heavily infested fields. The causal fungus was identified as Phytophthora nicotianae based on following mycological characteristics. Sporangium: readily formed in water, papillate, noncaducous, ovoid to spherical, 23~$56{\times}$~34 $\mu\textrm{m}$ in size. Oogonium: spherical, smooth walled, 18~26 $\mu\textrm{m}$ in size. Oospore: aplerotic, globose, 16~24 $\mu\textrm{m}$ in size. Antheridium: amphigynous, unicellula, spherical. Chlamydospore: abundant, spherical, 16~32 $\mu\textrm{m}$ in size. Sexuality: heterothallic. Optimum growth temperature was about 25~$30^{\circ}C$. Pathogenicity of the isolate was confirmed on host plant and the fungus was identified as Phytophthora nicotianae. This is the first report of Phytophthora blight of Daphne odora in Korea.

• Korean Journal of Plant Taxonomy
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• v.51 no.4
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• pp.372-377
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• 2021

We report a previously unrecorded woody species, Stachyurus praecox Siebold & Zucc. (Stachyuraceae), in Korea. This species is considered to be endemic to Japan. Stachyurus praecox was collected for the first time in an evergreen forest on an uninhabited island of Bongsun-ri, Saengil-myeon, Wando-gun, Jeollanam-do in Korea. The inflorescence of the species was racemose and pendulous on the axils of the previous year's branches. Flowers bloomed from March to April. They were functionally dioecy but morphologically hermaphrodite. This woody species was named 'Wan-do-sul-kkot-na-mu' in Korean based on the shape of its inflorescence. Morphological characteristics and illustrations of this woody species have been provided with a distribution map and photographs of the natural habitat.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.100-108
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• 2022

We found Urtica dioica L., an unrecorded alien plant, in the Han River basin of Korea. U. dioica is considered to be native to Europe, much of temperate Asia and western North Africa. This plant has been introduced to many other parts of the world. In Particularly, it reported as an invasive species from East Asia (Japan), Oceania and South America. This species is distinguished from related Korean taxa of the genus by its unisexual flower and dioecious plant species. In the Neighbor-Joining tree, U. dioica samples from the Han River Park (Sangam-dong, Mapo-gu, Seoul) and Yangjaecheon Stream (Daechi-dong, Gangnam-gu, Seoul) clustered into a clade consisting of a U. dioica s.s. Here, we provide a precise description, illustrations, a key to the related taxa, and photographs of its habitat.

• Journal of Life Science
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• v.31 no.6
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• pp.537-542
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• 2021

Schisandra nigra Max., a dioecious plant native to Jeju Island in Korea, is cultivated on a small scale for fruit production. As fruit-producing female individuals are generally considered to be more valuable than male, early identification of plant sex at the seedling stage is important. In this study, a sequence-characterized amplified region (SCAR) marker associated with a female-specific region in the genome of S. nigra was investigated. Of 120 randomly amplified polymorphic DNA (RAPD) primers, one primer (OPB-03) consistently amplified a 749 bp band in female plants. The female-specific PCR product was isolated and cloned, and the nucleotide sequences were then determined. Southern hybridization performed using the female-specific fragment as a probe produced positive signals only in genomic DNA from the female plants. This result revealed that the 749 bp segment of DNA was present in the genome of female plants but absent in the genome of male plants. A SCAR primer pair was designed based on the RAPD marker to amplify a 436 bp fragment in the genomic DNA of female plants. This primer pair amplified the expected size of DNA fragment in female plants and four monoecious individuals collected from a natural population. The SCAR marker identified in this study can be used to distinguish female-flowering individuals at the seedling stage.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.342-349
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• 2015

Kiwifruit is a new fruit crop that was commercialized in the late 1970s. Recently, its cultivation and consumption have increased rapidly worldwide. Kiwifruit is a dioecious, deciduous, and climbing plant having fruit with hairs and various flesh colors and a variation in ploidy level; however, the industry consists of very simple cultivars or genotypes. The need for efficient cultivar improvement together with the evolutional and biological perspectives based on unique plant characteristics, have recently encouraged genome analysis and bioinformatics application. The draft genome sequence and chloroplast genome sequence of kiwifruit were released in 2013 and 2015, respectively; and gene annotation has been in progress. Recently, transcriptome analysis has shifted from previous ESTs analysis to the RNA-seq platform for intensive exploration of controlled genetic expression and gene discovery involved in fruit ascorbic acid biosynthesis, flesh coloration, maturation, and vine bacterial canker tolerance. For improving conventional breeding efficiency, molecular marker development and genetic linkage map construction have advanced from basic approaches using RFLP, RAPD, and AFLP to the development of NGS-based SSR and SNP markers linked to agronomically important traits and the construction of highly saturated linkage maps. However, genome and transcriptome studies have been limited in Korea. In the near future, kiwifruit genome and transcriptome studies are expected to translate to the practical application of molecular breeding.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.131-144
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• 1995

To determine the structure of chromosome and to identify the sex chromosome of Ginkgo biloba and G. biloba var. fastigiata, the samples were obtained from root tips of trees growing in seven different provinences. The results are as follows. The basic number of somatic chromosomes was 2n=24. The range of a relative length of long chromosome was between $14.88{\sim}11.18{\mu}m$ and that of short chromosome was $8.11{\sim}6.24{\mu}m$. The chromosome sets were composed with one long pairs of m type and 11 short pairs of sm or st type. These short pairs showed the continuous descending in length. There was a satellite on the short arm of the Longest chromosome pair, and were satellites of the one or both long arm of 7th or 8th chromosome pair which were sm or st type, or the shortest st type chromosome pair. Sometimes, a satellite on the short arm of the longest chromosome pairs of Ginkgo biloba was double satellite, but that of G. biloba var. fastigiata was not. Karyotype was $2n=24=2^{2s}A^m+2B^{st\;or\;sm}+2C^{st}+2D^{st}+2E^{st}+2F^{st\;or\;sm}+2G^{sm}+2^{2s}H^{sm}\;or\;(^{1s}H^{sm}+H^{sm})+2I^{st}+2J^{st}+2K^{st}+2^{2s}L^{st}\;or\;(^{1s}L^{st}+L^{st})$. The male and female trees were not apparently distinguished by the chromsome structures. However the differences between the satellites could be used to identify the male and females. The male tree has double satellite on short arm of a longest chromosome pairs and females' has not. Also female trees have a satellite on a short chromosome more frequently than male trees.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.201-210
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• 1998

Sex ratios, and patterns of tree size and growth variation, resource allocation, spatial and age class distribution between the sexes were investigated in natural populations of the sexual trees, R. trichocarpa and R. sylvestris, and the mainly asexual, clonal tree, R. javanica of the dioecious Rhus (Anacardiaceae) distributed in Korea. Sex ratios for three species exhibited a significant degree of female bias, but among the populations, sex ratios were seen to vary quite widely. The measurement of tree size and annual increment of male trees in R. trichocarpa and R. sylvestris were significantly higher than those of female trees, but not significantly different in R. javanica. In all of the species, flowering branch number per individual and inflorescence number per branch of males outnumbered those of females. Branch number per individual, rachis(leaf) number per branch and rachis(leaf) number per inflorescence were more in females than in males. These results were considered as reproductive efforts to increase the pollen supply in males and the fruit production in females. Spatial distribution analysis in two different populations of R. trichocarpa indicated that males and females were randomly distributed in space, but seedlings were clumped around parental trees. Analysis of age class distributions between the sexual reproduction trees, R. triclaocarpa and R. sylvestris, and the asexual, clonal tree, R. javanica showed a different distribution in frequencies of males and females in each age class. These results showed that sexual and asexual reproduction tree species had almost different preference of habitats, and different sex ratio and annual growth.