• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.130-133
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• 2001

The purpose of this study was to investigate the decreased ratio of growth and yield by delayed seeding and flowering because drought of spring season often cause to delay seeding and sprout emergence. Equation of linear regression, y=-11.914x＋818.61 ($R^2$=0.916) and y=-16.96lx＋913.98 ($R^2$=-0.885) were derived from relationship between sowing date and yield of leading variety, Yangbaeckkae in 1999 and 2000, respectively. Yield was decreased by 7, 24, 40, 57, 74%, respectively, according as sowing date was delayed more 5, 15, 26, 36, 46 days than May 15, standard sowing date under the culture mulched with black P.E. film. Number of capsules per plant and length of stem bearing capsule were greatly decreased, while plant height, stem diameter, and day to flowering were affected little by delayed seeding date. Equation of linear regression, y=-0.7081x＋41.04 ($R^2$=0.861) was derived from relationship between flowering date and yield of 33 accessions. Yield was decreased by 7.7, 8.3, 9.2, 10.1, 11.2%, respectively, according as flowering date was delayed more 1, 2, 3, 4, 5 days than July 3, normal flowering date of Yangbaeckkae when it was sown on May 15, and the more flowering date was delayed, the more yield was decreased. Number of capsules per plant and length of stem bearing capsules were greatly decreased, but plant height and harvest index were decreased little by delay of flowering date

• Journal of Plant Biotechnology
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• v.50
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• pp.190-199
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• 2023

Date palm (Phoenix dactylifera L.: Arecaceae) is a dioecious species where only female trees bear fruits. In their natural state, date palms produce dates once a year. However, in Thailand, some trees were observed to produce dates during the off-season, despite no variations in morphology. The availability of such off-season fruits can significantly increase their market value. Interestingly, most female off-season date palms investigated in this study were obtained through micropropagation. Hence, there is an urgent need for genetic markers to distinguish female offseason flowering plantlets within tissue culture systems. In this study, we aimed to develop random amplification of polymorphic DNA-sequence characterized amplified region (RAPD-SCAR) markers for the identification of female off-season flowering date palms cultivated in Thailand. A total of 160 random decamer primers were employed to screen for specific RAPD markers in off-season flowering male and female populations. Out of these, only one primer, OPN-02, generated distinct genomic DNA patterns in female off-season flowering (FOFdp) individuals compared to female seasonal flowering genotypes. Based on the RAPD-specific sequence, specific SCAR primers denoted as FOFdpF and FOFdpR were developed. These SCAR primers amplified a single 517-bp DNA fragment, predominantly found in off-season flowering populations, with an accuracy rate of 60%. These findings underscore the potential of SCAR marker technology for tracking offseason flowering in date palms. Notably, a BLAST analysis revealed a substantial similarity between the SCAR marker sequence and the transcript variant mRNA from Phoenix dactylifera encoding the SET DOMAIN GROUP 40 protein. In Arabidopsis, this protein is involved in the epigenetic regulation of flowering time. The genetic potential of the off-season flowering traits warrants further elucidation.

• Korean Journal of Plant Resources
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• v.1 no.1
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• pp.1-7
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• 1988

This experiment were carried out to study the heritability, genotypic, pheno-typic and environmental correlation in four edible oil crops. Heritabilities of flowering date, maturing date, plant height and weight of 1, 000 grains in rape were high. A highly significant positive correlation was found between flowering date and maturing date, plant hight and ear length, number of pods per ear and flowering date, maturing date and plant hight, The number of seed per pod showed also significant positive correlation with flowering or maturing date as well as with the relationship between weight of 1, 000 grains and plant height or ear length inrapeseed, respectively. Heritabilities of maturing date, length of stem with eapsule and number of seed per capsule were high, in sesame. Genotypic correlation between plant height and length of stem with capsule, length of stem with capsule and number of capsule per plant, number of capsule per plant and weight of 1, 000 grains, weight of 1, 000 grains and yield were highy positive in sesame. Heritabilities of flowering date, length of main stem, weight of 100 grains and number of shells per square meter in peanut were high, There was positive genotypic correlation between length of main stem and yield, number of shells per quare meter and matured seed ratio, number of shells per square meter and yield, 100 grains weight and yield. On the other hand, a significant negative correlation appeared between flowering date and yield. Heritabilities of days to flowering, stem length, stem diameter and weight of 1, 000 grains in perila were high. There was positive genotypic correlation between stem length and stem diameter, number of pods per plant, stem weight etc, between number of internodes and number of pods per plant, stem weight, number of valid branches and number of pods plant as well, respectively. While, a significant negative correlation was observed between number of valid branches and weight of 1, 000 grains, between number of pods per plant and weight of 1, 000 grains.

• Journal of Ginseng Research
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• v.3 no.1
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• pp.35-39
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• 1979

Present studies were carried out to clarify the variation of flowering date in the variants of Korean ginseng Plants. In general, the variation of flowering date of violet-stem variant was found to be mere variable as compared with that of yellow-berry variant. And flowers began to bloom earlier in yellow-berry variant than in violet-stem variant. In violet-stem variant as well as in yellow-berry variant, the flowering date of 5-year old plants was earlier than that of 3- and 4-year old plants. As for the flowering date according to the different lines, the third line was earlier than the first or the fifth line.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.111-118
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• 2015

The objective of this study was to determine the response of rapeseed (Brassica napus) to different planting date in the spring and varieties on growth and flowering characteristics. Eight rapeseed varieties were sowed at 10 day interval from 1st to 31th of March at Muan and Jeju in Korea. Significant planting dates and rapeseed varieties effects for growth, start of flowering and duration. As the planting date was being delayed, plant length and flower number were decreased, but branch number was increased. And, start of flowering date was retarded and flowering duration decreased with later planting date. Days from planting to flowering was shortened as seeding date was delayed and shortening degree was similar between experimental locations, Muan and Jeju. The days to flowering for rapeseed about 73~94 days for 1st March and then decreased to 57~71 days for the 31th March of planting date. 'Tammiyuchae' and 'Mokpo 111' seeded on each planting date come into blossom more earlier about 10 days as compared to 'Tamlayuchae' and 'Naehanyuchae'. The duration of flowering for the B. napus varieties was shortened as planting date was delayed. The results revealed that flowering characteristics of rapeseed can be greatly enhanced by planting as early as possible, and early flowering varieties i.e. 'Tammiyuchae' and 'Spring' were the most suitable varieties among the tested varieties for planting in the spring.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.167-170
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• 2005

To obtain some information on the change of antioxidant components of seeds during grain filling stage as affected by the sowing dates, lignan compounds were investigated according to days of flowering under different sowing dates. Sesamin and sesamolin contents showed significantly different by days of flowering and varieties. Both of sesamin and sesamolin content increased after flowering and reached highest at 40 days of flowering, but they started to decrease thereafter, Sesamin and sesamolin contents of sesame seeds changed with sowing dates. Generally, late sowing date of May 30 showed relatively higher accumulation rate of sesamin and sesamolin contents rather than other sowing dates, but overall patterns were a little different by varieties and lignan compounds. In Yangbaekkae, sesamin and sesamolin contents showed relatively higher at sowing date of May 30, but Yanghuckkae showed higher sesamin and sesamolin contents till 20 days of flowering when sowing date of May 30, but it showed to change that both lignan contents were relatively higher under sowing date of May 10.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.47-55
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• 2020

This study was conducted to evaluate the flowering characteristics of 22 soybean (Glycine max Merrill) varieties of North Korea and classify the flowering group by the flowering date. The flowering date and the days required for flowering with the different planting times on May 31, June 19, June 30, July 3, and July 4 were investigated at the agricultural experimental field of Korea University for three years from 2017 to 2019. The flowering date and the days for flowering of "Yeonpungkong", an early maturing soybean cultivar of Korea, were July 18 and 48 days, respectively, at the planting time of May 31, those of "Daewonkong", a mid-late maturing cultivar, were July 30 and 60 days, respectively. Based on the flowering dates of "Yeonpungkong" and "Daewonkong", North Korean soybean varieties were classified into six flowering groups. Eight North Korean soybean varieties had the flowering dates earlier than "Yeonpungkong", including "Brekkhat" classified into the early flowering group. The range of flowering date was July 2 to 15 at planting time of May 31. Twelve North Korean soybean varieties had flowering dates similar to or later than "Daewonkong", including "Chang Dan Bac Mok" classified into the mid-late flowering group. The range of flowering date was July 24 to 30 at the planting time of May 31. For flowering response to environmental stimulus, all of the mid-late flowering varieties of North Korea responded to "photosensitive or day-length" for flowering reaction. The early flowering varieties were divided by "photosensitive" response and "temperature" response variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.437-442
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• 2002

To breed high quality and yield peanut variety according to select the short flowering duration, fifteen germplasms (1 virginia,7 spanish,6 valencia types and var, Daekwang) were investigated the flowering habit and agronomic characteristics from 1998 to 1999. Emergence date of the selected short flowering duration germplasms (SPFGs) was earlier 1-3 days and middle or small seed than that of var, Daekwang. Main stem length was longer 57cm but the number of branches, pods, 100-seed weight, and pod weight per plant was reduced 25%, 23%, 42%, 46%, respectively, in SPFCs comparing to var, Daekwang. The flowering date in SPFGs was similar but the flowering duration was earlier 5-16 days than that of var, Daekwang (52 days). Varieties that flowered shorter duration than 50 days were 18.8% among the SPFGs. The number of total flowers in SPFGs was fewer 50% than that of var, Daekwang. The rate of flowering inhibition were 50-52% than that of var Daekwang. The frequencies of flowering duration (under 50 days) were 7.7% in virginia, 46.2% in spanish, 53.9% in valencia. The effect of shading treatment on rate of flowering inhibition were 11%, but number of branches and pods were reduced by 27-31% in valencia type compared to non-shade. Correlation coefficient was significant positively ($r=0.9314^*$ virginia, $r=0.9551^*$ spanish, $r=0.9551^*$ valencia) between the air temperature and flower number, The frequency of peg and pod number on 1st to 2nd nodes in SPFGs were more 3-12%, 21-26% than that of var. Daekwang. The rate of mature pods at 80 days after flowering were higher 12-17% than that of var, Daekwang (68%). Correlation coefficient was high significant negatively between date of first flower and flowering date, the ratio of mature pod.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.139-146
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• 2008

To clarify the relationship between the timing and the duration of flowering among populations, plants, and individual flowers, the dates of flower budding, flowering and deflowering were monitored for ten woody species from March 1 to June 30, in 2005, 2006 and 2007, in temperate deciduous forests at three sites of Namsan, and individual plants from seven woody species were monitored from March 1 to May 31, in 2006. Total durations of flower budding, flowering, and deflowering varied among the plant species. Three durations of these phenological stages of Stephanandra incisa were the longest (74 days, 109 days, and 101 days, respectively), and those of Prunus serrulata var. spontanea were the shortest (7 days, 7 days, and 4 days, respectively). For each species, phenological durations varied among years but were similar among the study sites in the same year. There was no relationship between flowering time and flowering duration on the population level. On the plant level, the duration of flower budding was over 11 days in all specie; S. incisa had the longest duration (73.3 days), and that of Styrax japonica was long as well (29.0 days), while that of Prunus leveilleana was the shortest (11.3 days). The longer the mean flower budding duration, the greater the difference among the plants within a species. The flowering duration of for S. incisa was 92.2 days, while that of Forsythia koreana was 27.2 days. The flowering durations of all other species were $10{\sim}20$ days. The deflowering duration was 92.0 days in S. incisa and <15 days in all other species. Differences among the plants in deflowering duration were smaller than those of the other phenological stages. In the species that flowered in April, the correlation coefficient between the flowering duration and the first flowering date was negative and significant. However, in the species that flowered in May, the correlation between flowering duration and the first flowering date was not significant. For individual plants of all species except for S. alnifolia, the earlier the flowering time, the longer the flowering duration. Differences between flowering time and flowering duration across years were significant in six species.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.57-72
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• 2022

In this paper, we aimed to examine the flowering dates of cherry blossom and the peak dates of maple leaves in South Korea, by the combination of temperature observation data from ASOS (Automated Surface Observing System) and NDVI (Normalized Difference Vegetation Index) from MODIS (Moderate Resolution Imaging Spectroradiometer). The more recent years, the faster the flowering dates and the slower the peak dates. This is because of the impacts of climate change with the increase of air temperature in South Korea. By reflecting the climate change, our statistical models could reasonably predict the plant phenology with the CC (Correlation Coefficient) of 0.870 and the MAE (Mean Absolute Error) of 3.3 days for the flowering dates of cherry blossom, and the CC of 0.805 and the MAE of 3.8 for the peak dates of maple leaves. We could suppose a linear relationship between the plant phenology DOY (day of year) and the environmental factors like temperature and NDVI, which should be inspected in more detail. We found that the flowering date of cherry blossom was closely related to the monthly mean temperature of February and March, and the peak date of maple leaves was much associated with the accumulated temperature. Amore sophisticated future work will be required to examine the plant phenology using higher-resolution satellite images and additional meteorological variables like the diurnal temperature range sensitive to plant phenology. Using meteorological grid can help produce the spatially continuous raster maps for plant phenology.