Differentiation of bud meristems and cataphylls during adventitious bud formation on embryos of Picea abies

1989 ◽  
Vol 67 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Sara Von Arnold ◽  
Chris Hawes
Keyword(s):  
Picea Abies ◽  
Adventitious Bud ◽  
Bud Formation ◽  
Meristematic Cells ◽  
Cell Divisions ◽  
Adventitious Bud Formation ◽  
Cytokinin Treatment ◽  
Meristematic Activity ◽  
Xylem Elements ◽  
Needle Primordia

Embryos of Picea abies were pulse-treated with benzyladenine for 24 h and then cultured on medium lacking growth regulators. Meristemoids developed on all embryos during the 2nd week after the cytokinin treatment. Cells within the meristemoids divided randomly. As the meristemoids developed, further cell divisions became more organized so that separate regions of meristematic activity could be distinguished within each meristemoid. These meristematic regions developed into individual nodules and each nodule developed further into either a bud meristem or a cataphyll. Cataphylls were composed of unorganized, vacuolated, thick-walled cells whereas bud meristems were composed of organized meristematic cells. Later, xylem elements developed at the base, and needle primordia at the top of bud meristems. The bud apex had cytohistological zonation typical of conifers. The appearance of the developing adventitious buds depended on the number of cataphylls formed per bud as well as on the marginal expansion of the cataphylls.

Utilization of Different Seedling Explants for in Vitro Propagation of Hibiscus syriacus

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 478e-479
Author(s):  
M.M. Jenderek ◽  
A.J. Olney
Keyword(s):  
Callus Formation ◽  
Adventitious Bud ◽  
Root Explants ◽  
Petiole Explants ◽  
Bud Formation ◽  
Hypocotyl Explants ◽  
Leaf Petiole ◽  
Adventitious Bud Formation ◽  
Hibiscus Syriacus

Hibiscus syriacus is a difficult species in micropropagation due to its endogenous contamination and recalcitrant shoot formation; therefore, studies on using explants other than shoot tip or axillary buds of growing shrubs were initiated. Three different seedling fragments (root, hypocotyl, and leaf petiole) from aseptically germinated seedlings of hibiscus (var. Aphrodite) were evaluated for adventitious bud formation, shoot and leaf development. The explants were cultured on McCown's woody plant basal salt medium supplemented with KNO3 (800 mg/L), adenine sulfate (80 mg/L) and MS vitamins containing BA or 2iP or TDZ at 0.5, 1.0, 2.2, 4.4 and 10 mM. Adventitious buds were present on all of the three different explants grown on medium containing TDZ; however, the most abundant bud formation, with many small leaves originating from callus was observed on hypocotyl explants cultured on medium with 1 mM of TDZ. Petiole explants were the most frequent to develop short shoots (≈15 mm) and one to nine leaves without callus formation, where 70% of hypocotyl and the root explants formed leaves originating from callus. Callus was induced on all explant types regardless of the level or type of cytokinin used. However, the number of shoots produced by any explant type was low, petioles cultured on 0.5 and 1mM of TDZ were the most suitable material for non-callus shoot development in H. syriacus. Hypocotyl explants proved to be an excellent source for adventitious bud formation but their ability to develop shoots needs to be investigated.

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