• Korean Journal of Plant Taxonomy
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• v.48 no.3
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• pp.218-229
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• 2018

Myanmar's plant diversity is expected to be very high given the wide variety of climates and the diverse vegetation and geographical features of the country. Since the publication of Kress et al.'s plant checklist in 2003, new and unrecorded species have been constantly reported by various botanists, but much of Myanmar's flora requires more intensive examinations. We conducted joint floristic surveys of several Ywangan areas, including the Panlaung-Pyadalin Cave Wildlife Sanctuary in southern Shan State of Myanmar. The initial identification of seed plant specimens collected from three short floristic expeditions revealed that 23 species were newly recorded species in Myanmar. More than half of these were found to be geographically notable species, which are known to be endemic to neighboring countries such as China (4 spp.), Thailand (6 spp.), and India (2 spp.). A considerable number of these unrecorded species are distributed in the limestone areas of neighboring countries, reflecting the geological characteristics of the survey area. The results of this study reemphasize the need for intensive and continuous research on the flora of Myanmar for a more comprehensive understanding of the distribution patterns of flowering plants in Southeast Asia.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.452-457
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• 1998

Thirty-eight isolates of Phytophthora sp. caused rots on roots and basal stems were collected from five flowering plants from 1992 to 1997 at eight cultivation areas in Korea. All the isolates were identified as P. nicotianae based on following characteristics. The fungus produced markedly papillate, not caducous and ovoid to spherical sporangia, abundant chlamydospores, and small oospores with amphigynous antheridia only when paired with either A1 or A2 mating type. All isolates grew well at 35$^{\circ}C$ and showed distinct arachnoid colony patterns on CMA and PDA. Sizes of sporangia and chlamydospores of five representative isolates from each plant averaged 43-52$\times$30-38 ${\mu}{\textrm}{m}$ and 28 ~34 ${\mu}{\textrm}{m}$. Mating type of the isolates was either A1 or A2, and oogonia and oospores were measured as 28~31 ${\mu}{\textrm}{m}$ and 21~25 ${\mu}{\textrm}{m}$. PCR-RFLP analysis of rDNA of the five isolates resulted that restriction band patterns of the small subunit and ITS regions were identical to a perilla isolate of P. nicotianae, but distinct from P. cactorum and P. capsici. Cross inoculation tests showed that the five isolates had pathogenicity to lily, christmas cactus, anthurium, baby's breath and carnation with different degrees. However, each isolate showed stronger pathogenicity to its corresponding original host than others. Among five lily cultivars Georgia and Quririna were more susceptible than Napoli and others. This is first report of Phytophthora root and stem rot of lily, Christmas cactus, anthurium, baby's breath and monochoria in Korea.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.615-623
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• 2020

Brassica rapa is one of the most valuable vegetable crops worldwide. Cultivated varieties of B. rapa exhibit diverse developmental and morphological appearances, which includes important vegetables, oilseeds, and fodder crops. In this study, various phenotypes of recombinant inbred lines (RILs) of B. rapa were investigated, including their responses to five different pathogenic Botrytis cinerea isolates, responses to aphid and thrips during flowering stages, days to flowering, and plant heights. Responses of 113 RILs to five different B. cinerea isolates showed variations, suggesting that genetic factors controlling resistance or tolerance against each isolate were dependent on isolate/genotype pairs. Correlation analysis was performed to understand the nature of genetic factors and the relationship among these phenotypes. Although high levels of correlation were not detected between phenotypes assessed in this study, statistically significant correlation was detected for several combinations. Significant positive correlations were found for different B. cinerea isolates, supporting that certain levels of commonality could exist in genetic components controlling resistance against different B. cinerea isolates. Based on correlation analysis using numbers of insects counted on plants, it was speculated that genetic factors responsible for aphid tolerance or repellence might be also involved in the response against thrips. Relationship between vegetative growth and tolerance against B. cinereal or insects is rather more complicated. However, it was observed that shorter plants appeared to have a certain level of tolerance or repellence against both aphids and thrips. Data presented in this study could be used to assist further genetic studies and breeding efforts to obtain Botritis and insect resistance for B. rapa.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.25-31
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• 1985

For shortening the tobacco breeding cycle, seedlings with 6, 8 and II leaves of 2 flue.cured tobacco varieties, day. neutral type and photoperiod-sensitive type, were grown in controlled-environment room (CER), programmed for temperature of $18^{\circ}C$ and 8.hour day period of 30 klux, for 20, 30 and 40 days. All of plants of day.neutral type variety treated in CER, regardless of seedling stage and duration, flowered earlier than the untreated plants. In the 6.leaf seedlings stage of photoperiod-sensitive type variety, plants treated for 20 and 30 days in CER did not accelerate the flowering. the tobacco plants, treated with low temperature for 20 days at 8.leaf seedling stage, flowered earlier in comparison with. the other treatment.

• Genes and Genomics
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• v.40 no.12
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• pp.1259-1267
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• 2018

Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high commercial value due to its high nutritional values and favorable tastes. However, irregular bearing attributed to unstable flowering is a major ongoing problem for litchi producers. Previous studies indicate that low-temperature is a key factor in litchi floral induction. In order to reveal the genetic and molecular mechanisms underlying the reproductive process in litchi, we had analyzed the transcriptome of buds before and after low-temperature induction using RNA-seq technology. A key flower bud differentiation associated gene, a homologue of FLORICAULA/LEAFY, was identified and named LcLFY (GenBank Accession No. KF008435). The cDNA sequence of LcLFY encodes a putative protein of 388 amino acids. To gain insight into the role of LcLFY, the temporal expression level of this gene was measured by real-time RT-PCR. LcLFY was highly expressed in flower buds and its expression correlated with the floral developmental stage. Heterologous expression of LcLFY in transgenic tobacco plants induced precocious flowering. Meantime, we investigated the sub-cellular localization of LcLFY. The LcLFY-Green fluorescent protein (GFP) fusion protein was found in the nucleus. The results suggest that LcLFY plays a pivotal role as a transcription factor in controlling the transition to flowering and in the development of floral organs in litchi.

• Molecules and Cells
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• v.42 no.5
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• pp.406-417
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• 2019

RICE FLOWERING LOCUS T 1 (RFT1) is a major florigen that functions to induce reproductive development in the shoot apical meristem (SAM). To further our study of RFT1, we overexpressed the gene and examined the expression patterns of major regulatory genes during floral transition and inflorescence development. Overexpression induced extremely early flowering in the transgenics, and a majority of those calli directly formed spikelets with a few spikelets, thus bypassing normal vegetative development. FRUITFULL (FUL)-clade genes OsMADS14, OsMADS15, and OsMADS18 were highly induced in the RFT1-expressing meristems. OsMADS34 was also induced in the meristems. This indicated that RFT1 promotes the expression of major regulatory genes that are important for inflorescence development. RFT1 overexpression also induced SEPALLATA (SEP)-clade genes OsMADS1, OsMADS5, and OsMADS7 in the greening calli before floral transition occurred. This suggested their possible roles at the early reproductive stages. We found it interesting that expression of OsFD1 as well as OsFD2 and OsFD3 was strongly increased in the RFT1-expressing calli and spikelets. At a low frequency, those calli produced plants with a few leaves that generated a panicle with a small number of spikelets. In the transgenic leaves, the FUL-clade genes and OsMADS34 were induced, but SEP-clade gene expression was not increased. This indicated that OsMADS14, OsMADS15, OsMADS18, and OsMADS34 act immediately downstream of RFT1.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.146-152
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• 2013

The photosynthetic rates according to leaf positions in tomato plants were investigated in relation to leaf age and flowering rate. In the experiment investigating the diurnal change of photosynthetic rates, three leaves below the 4th cluster was checked every hour from 2 hours before sunrise and 3 hours after sunset. It was checked twice with the replication of 3 plants. The photosynthetic rate increased sharply for 1 hour right after sunrise and remained steady until 2 hours before sunset. This trend can be applied to determine the irrigation schedule. In the experiment investigating the photosynthetic rates according to leaf positions, it three leaves below each clusters from 1st to 4th cluster were checked. Flowering rate was also investigated. The photosynthetic rates showed a decreasing tendency steadily after flowers bloomed fully, regardless of the leaf position. It seems to be because the leaves below the cluster with fully-bloom flowers lost their activities. This result suggests the flowering rate or the position of flower has deep relation with the photosynthetic rates of the concerned leaves. From the results the leaves under flowering cluster may be the good part to investigate the photosynthetic rate to evaluate the crop's activity, even the photosynthetic rates are different according to the position of clusters.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.726-731
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• 2013

Experiments were conducted to evaluate the effect of low temperature-darkness treatment on floral initiation in four kinds of Korean strawberry cultivars. Mother plants were planted on March 29 and daughter plants were raised for the experiment. Temperature treatment was done for 7, 14, and 21 days keeping $13^{\circ}C$ in cooling storage from August 29, September 5 and September 14 to September 21. After the treatment, flower bud initiation was examined by a microscope, and the seedlings were transplanted on hydroponic system with Yamazaki's strawberry solution of EC $0.8dS{\cdot}m^{-1}$ to check the flowering. 'Ssanta' and 'Maehyang' showed early flower bud initiation in 7 days treatment than 'Seolhyang' by microscope check. 'Ssanta', 'Daewang', and 'Maehyang' showed early flower bud initiation in 14 days treatment than 'Seolhyang'. There were no differences among the treatments in 21 days treatment. Percentage of flowering of 'Seolhyang' and 'Maehyang' by low temperature-darkness treatment didn't show any difference but 'Daewang' and 'Ssanta' showed high percentage of flowering. It suggested that low temperature-darkness treatment technique can be use for improving early flowering and yield of 'Ssanta' and 'Daewang' cultivars.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.38-43
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• 2010

To develop Korean native lilies as mini-potted plants, the effects of plant growth retardants on inhibiting stem elongation and improving flowering rate were evaluated. Bulblets of Lilium concolor var. parthneion (5-7 g) and L. dauricum (3-4 g fresh wt) derived from in vitro culture and then enlarged by field culture were applied with 0, 25, 50, or $100mg{\cdot}L^{-1}$ ancymidol, diniconazole, and uniconazole through bulb dipping, foliar spray, and drench. In L. concolor var. parthneion, uniconazole dipping most effectively reduced plant height by 60.7-78.3% depending on concentration compared with control without decreasing flowering percentage. In L. dauricum, dipping into diniconazole solution significantly retarded the plant height by 70.0-86.3% and improved flowering percentage by 8.3-18.2% compared to control of 0%. Drench of $25-50mg{\cdot}L^{-1}$ ancymidol was also effective on inhibition of stem elongation and improvement of flowering rate. Therefore, dipping into $50-100mg{\cdot}L^{-1}$ uniconazole solution in L. concolor var. parthneion and dipping into $25mg{\cdot}L^{-1}$ diniconazole solutions or drench of $25mg{\cdot}L^{-1}$ ancymidol in L. dauricum can be useful to produce the mini-potted plants.

• Journal of People, Plants, and Environment
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• v.23 no.5
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• pp.521-535
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• 2020

Background and objective: This study investigated plant type and color preference and conducted a psychological assessment for gardening activities of firefighters in a high-risk occupational group. Methods: A survey was conducted on 117 firefighters aged 39.01±9.17 in Sunchang in March 2020 to examine their preferences in plant type and color and conduct a psychological assessment of firefighters on gardening activities. Results: For plant experience and awareness, plant-related event showed the highest score, followed by plant preference tendency and plant growing experience. The level of plant gardening activities was higher among older age and higher job position. As a result of examining the quality of life according to the demographic characteristic with WHOQOL-BREF (World Health Organization Quality of Life Assessment Instrument), it was found that the quality of life was higher among the 20s-30s than 50s, firefighter position than fire lieutenant or higher, those with higher average monthly income, and the singles group than married (p < .05). The administration group showed lower scores than the fire suppression group working in the field, showing statistical significance. Most firefighters showed high preference for herbal plants among the 12 types of flowering plants, in the order of Rosmarinus officinalis>Lavandula spp.>Mentha piperita, Calendula officinalis. Pelargonium spp. was preferred the least out of the flowering plants, Lycopersicon esculentum was preferred the most out of 12 types of vegetable plants, while Angelica acutiloba was preferred the least statistical significance. For the preference of plant colors, yellow was the most preferred color, followed by white, blue, orange, red, and green, showing statistical significance. For the psychological survey responses of emotion words toward 6 plants colors, it was found that 'bright' was the emotion felt most strongly by the white, yellow, and orange groups, 'calm' and 'comfortable' by the green and blue groups, and 'fancy' by the red group. Conclusion: The effect of agro-healing programs can be increased by using mostly yellow plants when creating indoor healing gardens at the workplaces of fire officials in a high-risk occupational group, and using herbal plants and Lycopersicon esculentum in the gardens for agro-healing activities.