• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.67-72
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• 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 Plant Tissue Culture
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• v.26 no.2
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• pp.93-97
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• 1999

Shoot tips with 2 leaf primordia were cultured to induce shoot primordia in MS liquid medium supplemented with several concentrations of BA and hIAA under the conditions of 10,000 lux illuminations for 24 h and of vertical shaking of 2 rpm in carrot. Two F$_1$ hybrids and two male sterility lines were used. Shoot primordia were only induced in the medium supplemented with 2.0 mg/L of BA and 0.2 mg/L of NAA. Genotypic specificity and seasonal effect of donor parents on shoot primordia induction were not observed and average 15-20% of the planted dornes developed to shoot primordia. The induced shoot primordia were successfully propagated by subculture in the same medium. However, they were grown into three different types during multiplication, that is, the type with multiple small shoots on the surface, the type of without any shoot, and the type of callus. Shoot primordia clusters with small shoots on the surface differentiated multiple shoots successfully in 1/2 MS solid medium supplemented with 0.2 to 1.0 mg/L of IAA and 0.2 to 1.0 mg/L of kinetin. New shoot primordia with small shoots were well formed when pieces bigger than 2 mm in diameter of the out layer of the shoot primordia cluster with small shoots were subcultured. No differences of multiplication and shooting ability and chromosomal variation of shoot primordia were observed until the 13th sub-culture.

• The Korean Journal of Mycology
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• v.18 no.4
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• pp.198-202
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• 1990

Some factors effecting on the mycelial growth and primordia formation of Agrocybe cylindracea were investigated. Among supplements added into sawdust, wheat bran was the best for the mycelial growth, and its appropriate concentration was 30%. A variety of sawdust preparations was tested singly and in combinations. Oak sawdust and the combination of oak and larch sawdust were the most effective for the mycelial growth. The optimal moisture content was 65%, and the range of optimal temperature was $25\:{\sim}\:28^{\circ}C$. The favorable conditions for the primordia formation appeared to be similar to those of the mycelial growth. Among supplements added into sawdust, wheat bran 30% and the combination of wheat bran and rice bran 30% were the best for the primordia formation. Oak sawdust, and the oak plus larch sawdust and oak plus poplar sawdust were the best for the primordia formation. The optimal temperature for the primordia formation was $17{\pm}2^{\circ}C$.

• The Korean Journal of Mycology
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• v.16 no.2
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• pp.87-94
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• 1988

Electrophoretic isozyme patterns from mycelia, primordia, cap and stem of Pleurotus spp. collected in Korea were compared. Primordia, cap and stem of fruitbody showed very similar isozyme patterns but mycelial isozyme patterns were different from those of fruitbody. Isozyme patterns of malate dehydrogenase, acid phosphatase in Pleurotus ostreatus collected from different regions in Korea were similar but those of esterase, peroxidase, leucine amino peptidase and superoxide dismutase were different. Interspecific comparison of esterase isozyme patterns among Pleurotus ostreatus P. cornucopiae and, P. florida was very different and may be valuable subsidiary tool to conventional taxonomic techniques for identifying species of Pleurotus. A dendrogram by similarities of isozyme band pattern was presented.

• Geosciences Journal
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• v.23 no.4
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• pp.547-556
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• 2019

A new species of the most primitive rosenellid stromatoporoid Cystostroma, C. primordia sp. nov. is reported from the Hunghuayuan Formation (Lower Ordovician, Floian) of Guizhou Province in the South China Block and the Duwibong Formation (Middle Ordovician, Darriwilian) of the Taebaeksan Basin in mid-eastern Korea (North China Block). This species is the first representative of the genus found in both the North and South China blocks. Cystostroma primordia sp. nov. is characterized by the absence of denticles and distinctively smaller cyst plates (height 0.04-0.20 mm, length 0.09-0.39 mm) than any other known species of Cystostroma. The presence of C. primordia sp. nov. in Lower to Middle Ordovician strata of western Gondwana challenges the long-held view of the late Middle Ordovician emergence of Paleozoic stromatoporoids. The simple internal morphological features of this new species and its occurrence in the Lower Ordovician of South China strongly indicate that an Early Ordovician Cystostroma-type precursor from western Gondwana is located near the base of the stromatoporoid stock. This occurrence greatly preceded the late Middle Ordovician (late Darriwilian) stromatoporoid diversification in circum-equatorial regions worldwide.

• Korean journal of applied entomology
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• v.15 no.3 s.28
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• pp.153-159
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• 1976

Present paper was attempted to investigate the effects of the light on the sclerotium formation of some isolates of Sclerotinia sclerotiorum(Lib.) do Bary from lettuce, cucumber and rape. The investigations were performed in the both aspects inducing sclerotial primordia from the mycelial colony and developing such primordia. The cultures were grown on potato-dextrose agar and were treated with day-light fluorescent lamps. In the continuous light illumination for 21 days, numbers of sclerotial primordia and matured sclerotia were increased with increasing the light intensity up to about 500 Lux, but on the contrary the dry-weight of matured sclerotia was decreased. In the 800 Lux illumination, induction of the primordia was extremely depressed, and then matured sclerotia were almost not produced. Short-time illumination for 48 hours, although the light intensity was as high as 5000 Lux, increased the numbers of sclerotial primordia and matured sclerotia. Dry-weight of matured sclerotia, however, was slightly increased only at low intensity of 160 Lux. On the other hand, the light shock which u·as alternatively on-of light every one minute for 48 hours increased the number and dry-weight of sclerotia produced, but the former was more effective at 500 Lux shock and the later more effective at 160 Lux shock.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.525-527
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• 1998

This study was conducted to determine the optimum cultural condition and method for in vitro mass production of Hibiscus syriacus L. 'Honghwarang'. When callus induced in MS solid medium supplemented with 0.01 mg/L TDZ was cultured in liquid medium containing 0.01mg/L TDZ, callus growth and shoot primordia formation was most effective. Formed shoot primordia were regenerated into shoot in MS or 1/2 MS medium of growth regulator-free condition. Effects of mesh size, shaking speed on callus and shoot primordia formation were examined after 5 weeks. Callus and shoot primordia formation was formed most effectively at 10 mesh and 80 rpm shaking speed in liquid medium.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.412-418
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• 1989

The stem segments of Ailanthus altissima were cultured on the Murashige & Skoog's medium(1962) supplemented with 0.1 mg/l BAP and 1.0 mg/l 2, 4-D for callus induction and proliferation, Shoot primordia were observed as greenish regions on the surface of yellow-brown calli about 8 weeks after culture. Shoot primordia were selected and transferred to the MS media containing various combination of BAP and 2, 4-D. Among these combinations the shoot primordia cell clusters on the medium added to 0.5mg/l BAP and 0.01mg/l 2, 4-D exhibited the highest number of shoot formation. These shoots were successfully transferred on the solid MS medium with no growth regulators for the rootings.

• Journal of Mushroom
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• v.13 no.3
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• pp.223-227
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• 2015

The study was conducted to investigate the effects of post-incubation period and temperature treatment conditions during incubation on the uniform primordia formation and cultural characteristics of oyster mushroom (Pleurotus ostreatus). Three kinds post-incubation period; 25, 30, 35 days and control were applied for 30 days while two kinds incubation room temperature $23^{\circ}C$ and $26^{\circ}C$ and control were used $20^{\circ}C$. The substrate temperature during pre-incubation was of 'Suhan No. 1' and 'Gonji No. 7'. Oyster mushroom varieties tended to increase between $24^{\circ}C$ to $26^{\circ}C$ at 11 to 15 days after inoculation and then they were maintained in treatment temperature during post -incubation period. The $CO_2$ occurrence was at the highest at 6,500 ppm for 'Suhan No. 1' and 5,800 ppm for 'Gonji No. 7' at the time of the highest temperature increase. The ratio of un-uniformal primordia formation and the ratio of non-commercial fruit body were reduced by 40%, 10.5%, respectively compared to control for 'Suhan No. 1' when in the post-incubation temperature was $26^{\circ}C$, and incubated for 10 days and 15 days treatment. Also, 'Gonji No. 7' was reduced by 19%, 9.5%, respectively when in the post-incubation temperature was $26^{\circ}C$, and incubated for 10 days treatment. Therefore, the higher post-incubation temperature of room and longer post-incubation period resulted in the higher percentage of primordia formation of two cultivars.

• Journal of Plant Biology
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• v.11 no.3
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• pp.23-30
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• 1968

Using several varieties of Cymbidium, investigations were carried out to make clear how the protocormic tissue develops from the cultured explant. Explant to be cultured were prepared in several ways: exclusively apical meristem, apical meristem dissected out with the basal part attached, axillary bud primordia in their initial stage of development, or apical or axillary bud dissected out as a whole etc. It was observed that protocorms or protocormic tissues were developed from the explant's meristematic tissues regardless of where these tissues were located. Apical meristem, leaf primordia, leaf axil, or internodal part of young bud turned easily protocormic, while the scaly leaves of axillary bud or stem tissue of mother shoot turned quickly brwonish and died away. Both in axillary and apical bud explant alike, whether they were cultured whole or divided, some took quickly green color while others were slower, and some developed protocorms easily while others remained unchanged for months. Varietal difference as well as environmental factors seemed to be responsible for it. Further details should be clarified by histogenetical investigations.