Heung Kyu Moon

Growth response of Acacia mangium Willd. seedlings to arbuscular mycorrhizal fungi and four isolates of the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch

Some Acacia mangium Willd. plantations in Asia grow poorly due to low soil fertility and the absence of compatible mycorrhizal fungi. This legume tree can be colonized by arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi but inoculation is not routinely practiced. This study aimed to compare the effectiveness of AM fungi and four isolates of the ECM fungus Pisolithus tinctorius (Pers.) Coker and Couch (Pt) in promoting growth of A. mangium seedlings under glasshouse conditions. AM inoculants were: Glomus etunicatum, G. fasciculatum, G. macrocarpum and Gigaspora margarita and mixed species extracted from rhizosphere soil of a Populus stand in Suwon (AMKFRI), and Carex (AMM6) and Populus (AMM7) growing in mine tailings in Korea. Pisolithus isolates were from Philippines (PtPhil) and Korea (PtKFRI, PtMKACC, PtKACC). Generally, ECM fungi promoted height and diameter growth of A. mangium more than the AM inoculants. The Korean Pisolithus increased plant dry weight by 122–145%, mixed AM inoculants by 61–97%, and Glomus and Gigaspora by 45–72% over the control. PtKACC gave the highest root colonization and promoted the highest growth and concentration of most nutrients. Mycorrhizal root colonization was positively correlated with plant dry weight, Na, Fe and Cu concentrations and N, P, K, Ca, Na, Fe and Cu contents. In conclusion, the results provide strong evidence for benefits of mycorrhizal inoculation on A. mangium seedlings under glasshouse conditions. The Korean Pisolithus isolates (particularly PtKACC), and two AM fungi (AMKFRI and AMM6) are potential mycorrhizal inoculants but their effectiveness and persistence should be determined on degraded lands in tropical countries where A. mangium is being planted for rehabilitation.

Somatic embryogenesis and plantlet formation from a rare and endangered tree species,Oplopanax elatus

We tested the possibility of plantlet formation via somatic embryogenesis with leaf segments and mature zygotic embryos from a rare and endangered tree species,Oplopanax elatus. To induce calli, expiants were cultured under darkness in a solid MS medium containing 3% sucrose, 1g L-1 glutamine, and 0.3% gelrite. Treatment supplements included 2,4-D alone or in combination with thidiazuron. Generally, callus induction and growth were good from leaf expiants, whereas embryogenic calli could be induced only from zygotic embryos. These embryogenic calli were white or pale yellow and very friable. ABA and activated charcoal appeared to be important factors when inducing somatic embryos, with optimum levels being 0.1 mg L-1 and 0.02%, respectively. Many somatic embryos showed abnormalities during their development on the germination medium, but 35% could be converted if placed on a medium containing gibberellic acid (GA3). The germinating embryos sometimes formed secondary embryos at the lower portion of the hypocotyls. Normal or converted plantlets were acclimatized in an artificial soil mixture; their survival was about 60% after two months. This culturing system provides a feasible approach for regenerating plants, via somatic embryogenesis, from mature zygotic embryos.

Mass Propagation of Liriodendron tulipifera L. via Somatic Embryogenesis

Mass propagation of tulip tree (Liriodendron tulipifera L) via somatic embryogenesis was successfully achieved with immature samaras collected from adult trees. Embryogenic tissues were induced by culturing them samaras on 1/2 LM medium (Litvay`s) containing 2,4-D and BA. Somatic embryos developed from the embryogenic tissues and germinated to normal plants (emblings) upon transfer onto the same medium containing either AgNO or activated charcoal. So far, several factors appeared to influence both the induction of embryogenic tissues and germination of the embryos into plants. These include the collection time of samaras for the induction of embryogenic tissue, sucrose level in the culture medium, the level of both AgNO and activated charcoal, and plating density of somatic embryos on germination medium for maturation and germination of somatic embryos into plantlets.

Triterpenoid Saponin Contents of the Leaf, Stem and Root of Codonopsis lanceolata

Codonopsis lanceolata (Campanulaceae) has been used in traditional medicines, as its roots contain several kinds of 3,28-bidesmosidic triterpenoid saponin with high medicinal values. In this study, we induced hairy root-derived transgenic plants of C. lanceolata and analyzed triterpenoid saponins from the leaf, stem and root. Transgenic plants were regenerated from the hairy roots via somatic embryogenesis. The saponins are lancemaside A, B and E, foetidissimoside A, and aster saponin Hb. Transgenic plants contained richer triterpenoids saponin than wild-type plants. Major saponin lance- maside A was the most abundant saponin in the stem from transgenic-plant, 4.76 ㎎·1 �1 dry stem. These results suggest that transgenic plants of C. lanceolata could be used as medicinal materials for the production of triterpene saponins.

Effect of LEDs on shoot multiplication and rooting of rare plant Abeliophyllum distichum Nakai

Abstract This study was conducted to elucidate the effect of light sources and explant types on in vitro shoot mul-tiplication and rooting of a rare and endangered plant Abeliophyllum distichum . Both apical buds and axillary buds were used as explants under 4 different light sources, cool white florescent light (F), 100% blue light-emitting diode (LED) (B), 50% blue and 50% red LED mixture (BR), and 100% red LED (R). Clear difference was observed in terms of shoot proliferation by light sources types but not by position-dependent explant types. Multiple shoot induction rates were enhanced under both B and BR light sources. Spontaneous rooting was induced in shoot induction medium under B light source. Both the rates of rooting and numbers of roots per explant were higher in apical bud explants compared to axillary bud explants. Interestingly R light source stimulated shoot elongation but inhibited root deve-lopment. Therefore, our results suggest that the use of apical bud explants under B or BR light sources is suitable for

Somatic embryo induction and plant regeneration from cold-stored embryogenic callus of K. septemlobus

본 연구는 약용 및 식용으로 유망한 음나무의 대량생산 및 생식질 보존을 위한 기초 자료를 제공하기 위해 배발생 조직을 재료로 저온저장 기간별 SE 유도 및 식물체 재생을 시험하였다. 배발생 캘러스는 저온저장 6개월까지 정상적인 체세포배 형성이 가능하였으나 유도 빈도는 저장 기간에 따라 감소하는 경향을 보였다. ...

Effect of explant’s position and culture method on shoot proliferation and micro-cuttings for a rare and endangered species, Abeliophyllum distichum Nakai

Using either the apical or axillary bud of the endangered species Abeliophyllum distichum Nakai, we tested the effect of bud position and culture method on shoot proliferation and rooting. In shoot proliferation, the axillary bud explant was more effective than the apical bud and the effect was fostered by BA treatment, whereas no differences were observed in shoot elongation by the explant position. Spontaneous rooting was observed in the MS basal medium and resulted in conspicuous differences in the explant position : more than 80% in apical bud explant and 28% in axillary bud explant was achieved, respectively. The positional effects were also observed in BA pre-treatments: generally vertical culture method appeared to be better in shoot proliferation, growth, and rooting than that of the horizontal culture method regardless of the BA pre-treatment duration. The highest shoot multiplication was achieved through the vertical culture method with axillary bud explant, whereas the best shoot elongation and rooting was obtained using the vertical culture method with the apical bud explant. Apical bud explant was superior to axillary bud explant in ex vitro micro-cuttings and revealed a significant difference in shoot growth and root development. The above results suggest that explant position and culture method influence the efficiency of micropropagation for a rare and endangered plant Abeliophyllum distichum.

Effects of in vitro culture types on regeneration and acclimatization of yellow poplar ( Liriodendron tulipifera L.) from somatic embryos

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

Effect of tissue proliferation and somatic embryo induction in Larix kaempferi following treatment with organic nitrogen sources and plant growth regulators

This study was conducted to evaluate the effects of different types and concentrations of organic nitrogen sources (-Glutamine and casein hydrolysate, CH) and plant growth regulators (auxins and cytokinins) on embryogenic tissue proliferation and somatic embryo production in L. kaempferi. Overall, the highest tissue fresh weight was obtained at either 2 or 4 weeks in culture when 1,000 mg/L -Glutamine was added to the culture medium, which showed similar results with other treatments. In experiments with different types and concentrations of plant growth regulators on somatic embryo production, the highest production (426.3/90 mg tissue) was found when 0.2 mg/L IBA was added; however, no somatic embryos were induced following treatment with 0.2 mg/L BA or Kinetin. The effect of various concentrations of IBA on somatic embryo production was also tested. The best result (303/90 mg tissue) was obtained when plants were treated with 0.2 mg/L IBA; 1.0 mg/L IBA was also effective (281/90 mg tissue). The lowest result (109.3/90 mg tissue) was obtained with 5.0 mg/L IBA.

In vitro introduction adventitious shoots and plant regeneration of sengon (Paraserianthes falcataria (L.) Nielsen)

Adventitious buds were obtained from isolated cotyledons cultured on MS medium with various concentrations of 6-benzylamino purine (BA) and thidiazuron (TDZ). The highest numbers of adventitious buds were obtained on MS medium supplemented with 0.2 mg/L BA. Experimental culturing with half the petiole portion and half with the terminal segments were grown on MS medium contained with 0.2 mg/L BA. Frequency of the adventitious bud induction was variable accordingly to the type of cultured explants. Explants with the half petiole showed the highest adventitious bud induction rate (80%) compared to explants of half with terminal segment (20%). An elongated shoot from the buds and growth of advent roots were both possible on the 1/2 MS medium without a plant growth regulator. These results offer an effective way in which clonal propagation can be accomplished.