• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.193-200
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• 2010

Current rose cultivars are all composed of heterozygous genome due to long history of out crossing including interspecific hybridization. It has been adapted by artificial selection and crossing by breeders that mainly based on the crossing with fertile pollen derived from inter- or intra-specific hybridization. Pollen viability and germination ability tests provide valuable information for the designing of parentage for more successful breeding efficacy. In this study, we tested the pollen viability and germination ability in seven rose cultivars to find any relationship among several factors including pollen size, ploidy levels, and crossing compatibility. The pollen viability showed wide ranges from 39% 'Pinocchio' as minimum to 82% 'Scarlet Mimi' as maximum, whereas pollen germination rate were from 1% 'Mini Rosa' to 41% 'Scarlet Mimi' as a highest. Pollen size ranged from 41.3 to $45.4{\mu}m$ in large sized pollen and 30.7 to $37.4{\mu}m$ in small sized pollen. The mean diameter of large sized pollen is approximately 10-40% bigger than that of small sized pollen. There are positive relationships among ploidy level, total chromosome length, and pollen size. Crossing list showed that seed setting ratio and seed germination were related to pollen viability, pollen germination, and ploidy level.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.107-111
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• 2008

This experiment was carried out to examine the effect of silicate on the rooting of cuttings and growth of cut chrysanthemum. In the first experiment, cuttings of chrysanthemum 'Pink Pixie Time' were grown in a 3 L medium which was supplemented with silicate at 0, 30, 60, or 90 g for examination of its effect on rooting of cuttings. In the second experiment, chrysanthemum 'Backwang' was grown in medium supplemented with silicate at 0, 60, 90, 120 or 240 g per 20 L medium. In the first experiment, the promotional effect of silicate increased with increasing silicate concentration in the medium, resulting in increased length of shoot and root. However, root dry and fresh weights were not affected by silicate concentration in the medium. In the second experiment, number of branches, plant height, number of nodes, and stem diameter in the silicate-supplemented treatments were greater than those in the control. However, dry matter was not affected significantly by silicate concentration in the medium. Fresh weights of the leaf, stem and root in the silicate-supplemented treatments were greater than those in the control.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.153-160
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• 2008

This experiment was conducted to find out an adequate shading level (0, 55, 74, and 95%) on the shoot growth of rooted cuttings of native Hydrangea serrata for. acuminata. New shoot height (NSH), length and width of leaf, and stem diameter under 55% shading were the greatest. Net photosynthetic rate under 55% shading was the greatest, while intercellular $CO_2$ concentration was the least in this treatment. The greatest content of photosynthetic pigments (total chlorophyll, carotenoid) was observed in leaves grown under a 74%, followed by a 55% shading level. Leaf stomata were observed on the abaxial surface, but those on adaxial surface in all shading treatments were not observed. In 95% shading, decreased stomatal density and development were observed. Higher stomatal density and development, however, were observed in 55% shading. Therefore, it is concluded that a 55% shading level was the optimum for growth of new shoots of rooted cuttings of native H. serrata for. acuminata.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.134-142
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• 2008

This work aims to obtain basic information for seed propagation of Hydrangea serrata for. acuminata. The germination percentage of the seeds taken on 15 November, 30 December, and 23 January was $90.0{\pm}4.16%$, $84.4{\pm}5.52%$, and $88.9{\pm}2.40%$, respectively. This suggest that seeds of Hydrangea serrata for. acuminata are non-dormant seeds. The optimum temperature for germination was $25^{\circ}C$ and light was necessary. Most of the growth parameters (shoot and leaf length, stem diameter, root length, no. of roots, T/R ratio, and fresh and dry wts.) were significantly greater at $25/20^{\circ}C$ and $25^{\circ}C$ than at the other temperatures. Low T/R ratio at relatively cool temperatures (15 and $20^{\circ}C$) was caused by suppressed top growth. In light quality treatment, red light (RL) significantly enhanced stem elongation. The greatest photosynthetic pigments (total chl, chl a/b, and carotenoid) were observed in seedlings grown in blue light (BL), followed by seedlings grown in RL+BL. When blue light was added, higher pigment contents were found. Effect of plug cell size (50, 72, 128, 162 and 200 cells) on the growth of seedlings was investigated. The highest top growth was observed in seedlings grown in 50 cell trays, followed by seedlings grown in 72, 128, 162, and 200 cell trays. However, there was no significant differences between 162 and 200 cell trays. Especially, smaller size leaves were observed in seedlings grown in smaller cell trays (lower volume and high plant density).

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.294-297
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• 2010

A new intermediate parent 'Wonye 30001' (Allium cepa L.) was developed by Bioenergy Crop Research Center, NICS in 2009. As a male sterile line, 'Wonye 30001' could be used for hybrid seed production by crossing with pollen parent. The first cross was conducted in 2000. Male sterile plants were selected from 'Ginque' breeding lines and fertile plants were selected from YG-1-1. The male sterile line 'Wonye 30001' has circular bulb and bulb weight of 260 g. As mid-late maturing type, lodging date is around May 20. Plant height and stem diameter are 57 cm and 15.9 mm, respectively. In seed harvesting characteristics, number of flower stalks and the length are 6 and 135cm, respectively. Flowering date of 'Wonye' is May 23 and is completely male sterile. 'Wonye 30001' is a promising male sterile line for hybrid bulb onion seed production.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.349-355
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• 2021

The effect of night temperature was investigated on mango (Mangifera indica cv. Irwin) for setting appropriate night temperature and managing mango cultivation in a greenhouse. Different night temperatures (10, 15, and 20℃) were treated from budding to fruit development in mango trees. As night temperature increased, the initiation of flowering, full blooming, fruiting, and fruit development tended to be accelerated. There were no significant differences in the growth of shoots flushed after the fruit harvest among trees treated with different night temperatures. The lengths of the flower stalk were the shortest at 10℃ of night temperature; however, there were no significant differences between 15℃ and 20℃ of the night temperature. The length, diameter, and weight of mango fruits were higher at 15℃ and 20℃ than 10℃. Soluble solid contents and acidities showed no difference; the firmness and skin color were better as the night temperature increased. Accordingly, setting the minimum night temperatures to 15℃ or 20℃ can increase the number of fruits and produce high-quality fruits when cultivating mango in the greenhouse. Even the minimum night temperature to 15℃ can reduce heating costs in the greenhouse.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.132-138
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• 2023

The Gymnocalycium mihanovichii has been an important export item of Korean flower industry for a long time. Although there is a high demand for grafted cactus from overseas, its production for export is limited. In this study, the growth and marketable yield characteristics of Gymnocalycium mihanovichii 'I-Hong' were compared between soil culture and ebb-and-flow hydroponic system with single- or double-tier bench. As a result, hydroponic methods with single-tier bench resulted in higher fresh weight and glove diameter compared to other cultivation methods. In the ebb-and-flow hydroponic system, hydroponic system with double-tier bench of grafted cactus traits has a lower growth rate than other cultivations. However, the hydroponic system with double-tier bench of grafted cactus significantly increased the yield. In conclusion, the yield from hydroponic system with double-tier bench was better than soil cultivation method. Although there were some differences in color depending on the cultivation method, it was considered that there was no difference in appearance of Gymnocalycium mihanovichii 'I-Hong'. Our results suggest the cultivation methods to overcome production constraints, expand their exports, and improve the value-added characteristics of grafted cactus.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.336-341
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• 2023

This study examines the characteristics of berries from secondary bearing shoots of 'Scintilla' southern highbush blueberry, grown hydroponically in the Jinju, Gimhae, and Uiryeong regions of Gyeongnam Province. Typically, 'Scintilla' forms flower buds at the tips of regular bearing shoots during the previous season, yielding berries in the current season. However, under heated cultivation, we observed a proliferation of secondary bearing shoots that produce berries in the same growing season. Flowering and harvesting on secondary bearing shoots were delayed by 52 and 36 days, respectively, compared to regular bearing shoots. However, these shoots exhibited a 54% increase in diameter and a 10% increase in length. We found no significant difference in berry size and soluble solid content between the two types of shoots. Notably, berries from the secondary bearing shoots had higher potassium and lower calcium and magnesium concentrations. We conclude that berries from secondary bearing shoots could be marketable, provided the bushes are healthy. These findings provide valuable insights for optimizing cultural practices to improve the yield and quality of blueberries under specific environmental conditions.

• Journal of Korean Society of Forest Science
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• v.21 no.1
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• pp.1-34
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• 1974

The author intended to investigate external and internal changes in the cone structure, changes in water content, sugar, fat and protein during the period of seed maturation which bears a proper germinability. The experimental results can be summarized as in the following. 1. Male flowers 1) Pollen-mother cells occur as a mass from late in April to early in May, and form pollen tetrads through meiosis early and middle of May. Pollen with simple nucleus reach maturity late in May. 2) Stamen number of a male flower is almost same as the scale number of cone and is 69-102 stamens. One stamen includes 5800-7300 pollen. 3) The shape is round and elliptical, both of a pollen has air-sac with $80-91{\mu}$ in length, and has cuticlar exine and cellulose intine. 4) Pollen germinate in 68 hours at $25^{\circ}C$ with distilled water of pH 6.0, 2% sugar and 0.8% agar. 2. Female flowers 1) Ovuliferous scales grow rapidly in late April, and differentiation of ovules begins early in May. Embryo-sac-mother cells produce pollen tetrads through meiosis in the middle of May, and flower in late May. 2) The pollinated female flowers show repeated divisions of embryo-sac nucleus, and a great number of free nuclei form a mass for overwintering. Morphogenesis of isolation in the mass structure takes place from the middle of March, and that forms albuminous bodies of aivealus in early May. 3. Formation of pollinators and embryos. 1) Archegonia produce archegonial initial cells in the middle and late April, and pollinators are produced in the late April and late in early May. 2) After pollination, Oespore nuclei are seen to divide in the late May forming a layer of suspensor from the diaphragm in early June and in the middle of June. Thus this happens to show 4 pro-embryos. The organ of embryos begins to differentiate 1 pro-embryo and reachs perfect maturation in late August. 4. The growth of cones 1) In the year of flowering, strobiles grow during the period from the middle of June to the middle of July, and do not grow after the middle of August. Strobiles grow 1.6 times more in length 3.3 times short in diameter and about 22 times more weight than those of female flower in the year of flowering. 2) The cones at the adult stage grow 7 times longer in diameter, 12-15 times shorter diameter than those of strobiles after flowering. 3) Cone has 96-133 scales with the ratio of scale to be 69-80% and the length of cone is 11-13cm. Diameter is 5-8cm with 160-190g weight, and the seed number of it is 90-150 having empty seed ratio of 8-15%. 5. Formation of seed-coats 1) The layers of outer seed-coat become most for the width of $703{\mu}$ in the middle of July. At the adult stage of seed, it becomes $550-580{\mu}$ in size by decreasing moisture content. Then a horny and the cortical tissue of outer coats become differentiated. 2) The outer seed-coat of mature seeds forms epidermal cells of 3-4 layers and the stone cells of 16-21 layers. The interior part of it becomes parenchyma layer of 1 or 2 rows. 3) Inner seed-coat is formed 2 months earlier than the outer seed-coat in the middle of May, having the most width of inner seed-coat $667{\mu}$. At the adult stage it loses to $80-90{\mu}$. 6. Change in moisture content After pollination moisture content becomes gradually increased at the top in the early June and becomes markedly decreased in the middle of August. At the adult stage it shows 43~48% in cone, 23~25% in the outer seed-coat, 32~37% in the inner seed-coat, 23~26% in the inner seed-coat and endosperm and embryo, 21~24% in the embryo and endosperm, 36~40% in the embryos. 7. The content compositions of seed 1) Fat contents become gradually increased after the early May, at the adult stage it occupies 65~85% more fat than walnut and palm. Embryo includes 78.8% fat, and 57.0% fat in endosperm. 2) Sugar content after pollination becomes greatly increased as in the case of reducing sugar, while non-reducing sugar becomes increased in the early June. 3) Crude protein content becomes gradually increased after the early May, and at the adult stage it becomes 48.8%. Endosperm is made up with more protein than embryo. 8. The test of germination The collected optimum period of Pinus koraiensis seeds at an adequate maturity was collected in the early September, and used for the germination test of reduction-method and embryo culture. Seeds were taken at the interval of 7 days from the middle of July to the middle of September for the germination test at germination apparatus.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.349-358
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• 2014

This study was conducted to determine the impact of elevated temperature in growing season on the growth and fruit quality of red pepper (Capsicum annuum L.) by cultivating pepper in the temperature gradient tunnels. Plant height, stem diameter, leaf number and total leaf area, fresh weight and dry weight increased at ambient $+2^{\circ}C$ temperature, whereas each leaf area decreased as temperature increased. The plants grown under ambient $+2^{\circ}C$ temperature showed the greatest number of flower and fruit. Fruit weight, fruit length and fruit diameter decreased as the temperature increasing gradually. Total fruit number, total fruit weight and total dry fruit weight was the highest at ambient $+2^{\circ}C$ temperature. Major free sugars of red pepper fruit were fructose and glucose. Free sugar content of red pepper according to the differences in harvesting times and in growth temperature showed a little differences. The yield of red pepper fruit at ambient $+2^{\circ}C$ temperature increased by 13% compared with the control. However, the yield of red pepper fruit at ambient $+4^{\circ}C$ temperature decreased by 20% as compared to control. Non-marketable fruits (diseased fruit, malformed fruit and small sized fruit) increased as the temperature rised.