• Journal of Life Science
• /
• v.16 no.3 s.76
• /
• pp.459-463
• /
• 2006

Cultivated garlic, Allium sativum L. is economically important for leaves and bulbs, which historically were used in Korea for spices and condiments of Korean food as well as medicine crops. This experiment was carried out to investigate the effect of development and differentiation on culture of A. sativum (cv: white 6) by explant position, hormone composition and sucrose concentration in culture media. Culture method was investigated to induce shoot primordium. Culture efficiency was better with lower tissue of foliage leaf in explant position and on the medium with NAA 0.02 + BAP 1.0 mg/l in hormone composition than any other. Precocious shoot and callus were induced from shoot apex. Shoot was efficiently differentiated on 4,000 mg/l sucrose with increasing concentration of BAP. Shoot primordium was also induced with liquid rotary culture by histological observation. Rhizoid was induced from callus tissue cluster on medium with NAA 0.02 + BAP 2.0 mg/l.

• Asian Journal of Turfgrass Science
• /
• v.11 no.2
• /
• pp.117-124
• /
• 1997

This study was carried out to investigate the growth and branching pattern of stolons at Korean lawn(Zoysia japonica Steud.) in the field condition. The results were summarized as follows ; 1.About 80% of observed lawns had one primary stolon. Among the lawns with several primary stolons, 30% of them had two primary stolons, 63% had three, and 7% had four. 2.The angles between the primary stolon and the shoot were increased from 0˚ to 52˚ according to the node order from the terminal shoot apex, and reached maximum angle at the 7th node. 3.The internode length was the longest in the middle position of stolon, and its growing rate which depends on months was increased from May to September. 4.The branching angles between primary and secondary stolon were from 44˚ to 53˚ in each node. The average left branching angle was about 48.20, right branching angle 47.8˚, and the total average branching angle was 48.00. 5.The rate of initial brabch was the highest at the 10th node in May, the 7th node in July and the 5th node in September. But, the initial branching rate at the 7th node in July was higher than any other that at the 10th node in May and the 5th node in September. 6.The distribution rate of secondary stolon in each node of primary stolon was the highest at the 7th node. 7.when the terminal shoot apex of primary stolon was damaged mechanically, the branching rate at the first node after the damaged region was highly increased to 62%. The results of this study may be suggested that the secondary stolon begins to branch with the angle of 480 from the 7th node of the normal primary stolon, and those may be used as a basic data for the branching simulation in lawn.

• Journal of Plant Biotechnology
• /
• v.8 no.1
• /
• pp.43-50
• /
• 2006

The goal of this research was to develop an efficient cryopreservation protocol for germplasms of yam (Diosorea batatas), that were cultivated in Korea. Comparative studies with four other cryogenic techniques and subsequent experiments for shoot regrowth were conducted. in vitro-grown shoot-apices of the D. batatas were successfully cryopreserved by encapsulation-dehydration. The maximum survival of shoot-apices could be achieved when the precultured (with 0.3 M of sucrose for one day) and encapsulated (with a 3%(w/v) Na-alginate solution) apices were dehydrated for $3.5{\sim}4\;h$ prior to direct immersion in LN (liquid nitrogen). The frequency of regrowth rate of cryopreserved apices was not decreased during 3-month storage period. The thawing method markedly affected survival of the cryopreserved apices, and thawing at $40^{\circ}C$ for 3 min produced the best results. When cryopreserved apices were post-cultured on the post-culture medium (MS), supplemented with $0.2mgl^{-1}$ of BA ($N_6$-benzyladenine) and $0.2mgl^{-1}$ of kinetin, they showed direct shooting without callusing.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.6
• /
• pp.273-277
• /
• 2005

Adventitious shoots were directly induced from leaf explants of R. glutinosa, an important medicinal plant. Proliferating shoot cultures were obtained by culturing leaf discs on Murashige and Skoog(MS) medium alone or combination with auxins and cytokinins. MS medium supplemented with 1 $mg/{\ell}\;BA\;and\;2\;mg/{\ell}$ IAA was the most effective, providing high shoot bud formation frequency without formation of intervening callus. The effect of leaf age on adventitious shoot formation was also investigated. The maximum shoot bud production (93.4%) was achived using 3rd leaf from apex of 6 weeks old plantlets after seed germination. Plantlet were rooted on an half-strength MS (1/2MS) medium containing 0.1 $mg/{\ell}\;IBA$. This prtocol is useful for clonal propagation and Agrobacterium-mediated transforamtion in R. glutinosa.

• Journal of Korean Society of Forest Science
• /
• v.94 no.2 s.159
• /
• pp.67-72
• /
• 2005

The objectives of this study were to identify the period of initiation of floral primordia in black locust (Robinia pseudoacacia L.) and subsequent development of floral buds until following spring. Four mature trees of black locust located in Suwon, Korea were selected. Bud samples were collected from the current-year shoots, starting from mid June to July every week, from August to October and from February to April every month. The buds were fixed in FAA solution, dehydrated, and imbedded in paraffin for microscopic observation. Buds collected on June 16, and 23, 1997, contained primitive primordia that might be interpreted as early floral primordia. By June 30, a bud showed a positive indication of inflorescence primordium with a well-formed shoot apex. All the inflorescence primordia observed throughout the collection periods were always associated with unique hairy appendages around the primordium and enclosed within a sclerenchymatous chamber. By July 7 and 15, a floral apex had early bud scales. By July 22, primitive inflorescence developed into visible arrangement of individual floral primordial By July 29, the inflorescence developed into whirl arrangement of individual floral primordia in a transverse section, but showed little further development until October 15. The inflorescence primordia seemed to over-winter at this stage. Buds collected from February 15 and March 24 the following year also showed no further development of inflorescence primordia. By April 7 the inflorescence started to show further development with elongated axis. At this time individual flowers were easily recognized.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.4
• /
• pp.481-487
• /
• 1983

The need to synchronize flowering in two lines of different maturities is frequently encountered in hybrid com (Zea mays L.) seed production. To establish the methods for synchrony of flowering in parent lines of different maturities be effects of clipping at 4 and 6-leaf stages of growth and two levels, clear polyethylene mulching and five different planting dates on flowering date growth and seed yield of two dent com inbred lines of different maturities were evaluated Clipping just above the shoot-apex delayed pollen sheeding 6 to 9days and silking 5 to 13 days but reduced stand and seed yield 30 to 70% and 67 to 81%. respectively. Clipping 5cm above the shoot apex delayed flowering 1 to 4 days without stand reduction but reduced yield 3 to 29%. Laterclipping was slightly more effective for delaying flowering than earlier clipping but reduced stand more severely when clipped just above the shoot apex. Under clear polyethylene film mulching, flowering of two lines was 13 to 15 days earlier and seed yield of B68 (late line) was significantly increased. As planting was delayed from April 18 to June 13, the number of days from planting to flowering of two lines decreased due to increase in air temperature. However, growing degree days (GDD) from planting to flowering of each lines was similar regardless planting dates indicating that GDD can be satisfactoryly used for choosing the planting dates of parent lines of different maturities. Seed yields of two lines were decreased with delaying planting dates.

• Journal of Bio-Environment Control
• /
• v.23 no.1
• /
• pp.56-59
• /
• 2014

Apex removal is a common practice in artichoke cultivation to harvest heads of lateral shoots. This experiment was carried out to investigate the effect of apex removal by different planting times on the growth and yield of Artichoke (Cynara scolymus L.) in open field. Two treatments (apex removal and no apex removal) at three different planting times ($1^{st}$: Sep. 27, 2011, $2^{nd}$: March 29, 2012, and $3^{rd}$: Sep. 21, 2012) were tested using 'Green Globe' variety. There was no difference in the head characteristics and the number of harvested head between the treatments. The head weight was heavier in no apex removal of 242.7 g than the apex removal of 170.8 g. The yield also increased in no apex removal by 25% (1,249 kg/10a) compared to the apex removal of 997 kg/10a at the first planting time. At the second planting time, there was no difference in the head weights between the treatments. But the number of the harvested head was higher in no apex removal with 10.8 than 8.2 of the apex removal. The yield of no apex removal was 2,660 kg/10a, which was higher than 1,848 kg/10a of apex removal. At the third planting time, the head weight increased in no apex removal with 253.5 g compared to the apex removal with 218.7 g. The yield of no apex removal was 1,405 kg/10a, which was higher than 1,148 kg/10a of the apex removal. All the tests at 3 different planting times showed that the artichoke yields were higher in no apex removal than in apex removal. Therefore, it is desirable to cultivate artichoke without removing the apex for the higher yield and labor saving in open-field cultivation in Jeju island.

• Journal of Life Science
• /
• v.16 no.3 s.76
• /
• pp.540-545
• /
• 2006

T-DNA-mediated transformation is a common method for generating transgenic plants with insertional mutagenesis. In order to identify important genes involved in shoot development, a system of promoter trap insertional mutagenesis was employed in Arabidopsis thaliana. For this system, an efficient promoter trap vector, pFGL561 was developed. The pFGL561 includes a basta-resistant gene, an intron with multiple splicing donor and acceptor sites, and a promoter-less GFP reporter gene. Using floral-dipping method, we made total 300 $T_1$ promoter-trap lines which were screened for GFP expression. GFP signals in the $T_1$ plants were detected with high frequency, 26.7%, and the signals were reconfirmed in $T_2$ plants. To isolate the genes that are involved in shoot development, phenotypes were analyzed in $T_2$ plants of the 19 $T_1$ lines that had GFP signals in shoot apex, and 6 $T_1$ lines were selected that had abnormal shoot development. These lines will be very useful for the investigation of shoot development.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2003.10a
• /
• pp.146-146
• /
• 2003

• Journal of agriculture & life science
• /
• v.43 no.6
• /
• pp.59-65
• /
• 2009

Combinations of plant growth regulators, darkness treatments, and the order of expanding leaves for explants were evaluated for optimizing in vitro shoot regeneration rate of 'Whangkeumbae' pear. In a MS medium, supplemented with $8.88{\mu}M$ 6-benzylaminopurine (BA) and $0.49{\mu}M$ indole-3-butyric acid (IBA), green foci were observed on the surface of the callus 8 days after culture initiation. Some adventitious buds were later induced from those green foci, resulting in the appearance of normal shoots. In a medium containing $22.20{\mu}M\;BA$, the surface of the callus became compact and greenish, and many adventitious buds were formed over the entire area of the callus surface. When comparing BA concentration via histological observation, the section which had been treated with $22.20{\mu}M\;BA$ exhibited closer cell aggregation than those with $8.88{\mu}M\;BA$. The darkness treatment enhanced the formation of adventitious shoots for up to 3 weeks. The youngest two expanding leaves, proximal to the shoot apex, were proved to be the most regenerative, and yielded the highest shoot number per regenerating leaf. A fourth strength MS medium, which was supplemented with $0.54{\mu}M\;NAA$, yielded good quality plantlets, with regard to root number and root length.