Growth of Cymbidium kanran rhizome was enhanced by higher NAA:BAP ratios in modified Murashige & Skoog (MS) media. Only vegetative shoots resulted from rhizomes cultured in vitro when lower NAA: BAP ratios were used. The rhizomes were induced from the axils of leaves when shoots were explanted to medium containing higher concentrations of NAA. Root formation of C. kanran was inhibited by the addition of either auxin or cytokinin to the culture media. Differentiation of the rhizomes into plantlets occurred when the concentrations of ammonium nitrate and potassium nitrate in MS medium were reduced. The modified MS medium containing lesser amounts of potassium nitrate and ammonium nitrate than those of the original MS media, and was optimal for the production of plantlets from rhizomes of C. kanran without addition of auxin and cytokinin.

Apical flower buds of Cymbidium goeringii Reichenbach ill. (ca 2 mm long) excised from inflorescences (ca 5 cm long) were explanted on modified Murashige & Skoog medium (=MS medium) supplemented with N6-benzyladenine (BA) and ~-naphthaleneacetic acid (NAA). Within 107 days of culture, swelling growth, chlorophyll synthesis, and subsequent rhizome differentiation were observed. MS medium containing 0.1 mg 1 1 BA and 10 mg 1-1 NAA was found to be optimal for initiating rhizome development and subsequent plantlet regeneration.Explants cultured on MS medium supplemented with i mg 1-1 NAA alone formed a mass of rhizome branches. Multiple shoots of rhizome branches were induced from apical segments when rhizomes were transferred to MS medium containing 0.1 mg 1-1 BA and 10 mg 1-1 NAA.

Abstract:In a controlled environment, light from light-emitting diodes (LEDs) has been associated with affecting the leaf characteristics of Eustoma. LEDs help plant growth and development, yet little is known about photosynthetic performance and related anatomical features in the early growth stage of Eustoma leaves. In this study, we examined the effects of blue (B), red (R), and white (W) LEDs on the photosynthetic performance of Eustoma leaves, as well as leaf morphology and anatomy including epidermal layer thickness, palisade cells, and stomatal characteristics. Leaves grown under B LEDs were thicker and had a higher chlorophyll content than those grown under the R and W LEDs. Leaves under B LEDs had greater net photosynthetic rates (A), stomatal conductance (g s ), and transpiration rates (E), especially at a higher photon flux density (PPFD), that resulted in a decrease in the intercellular CO 2 concentration (C i ), than leaves under the W and R LEDs. B LEDs resulted in greater abaxial epidermal layer thickness and palisade cell length and width than the R and W LED treatments. The palisade cells also developed a more cylindrical shape in response to the B LEDs. B LED leaves also showed greater guard cell length, breadth, and area, and stomatal density, than W or R LEDs, which may contribute to increased A, g s and E at higher PPFDs.

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The major problem with in vitro propagation of lilies is small bulblet size, and the initial size of bulblets not only strongly affects growth and morphogenesis rates but also the transition between various vegetative and reproductive phases during development after planting. Therefore, bulblet growth is the most important factor in understanding how lily bulblets grow in vitro and the role of starch converted from sucrose in the medium on the growth mechanism in lilies, with the aim of revealing the effective in vitro culture condition to enhance in vivo performance of lily bulblets. The results of this study show bulblet growth correlates with the use of starch granule reserves inside explant tissue and in the medium. The main factor determining the growth of bulblets in vitro is explant size due to internal storage of starch, which plays a vital role in bulblet growth irrespective of cultivar. Furthermore, internal storage of sucrose plays a vital role and influences regeneration and bulblet growth in both in vitro and in vivo cultures. Therefore, the size of the bulblets produced in vitro strongly affects performance after planting. There is a high correlation (R 2 = 0.9672) between bulb weight after the growth season and initial bulb weight and therefore, the ontogenetic age of bulblets at planting. Hence, culturing lily scale explants in a high sucrose concentration during regeneration of bulblets in vitro to increase bulblet size is the main point of interest for future production.