The effect of antibiotics on elongation and callus and bud formation from embryonic tissue of Piceaglauca

Strategies for the selection of transformed cells and the counterselection (clearing) of Agrobacterium in genetic engineering requires a balance between the selection pressures and the normal morphogenetic response of transformed tissue. In this paper, we report the effect of antibiotics used for plant transformation studies on the elongation and induction of buds from embryos and the induction of callus from seedling tissue of Piceaglauca. Carbenicillin, ampicillin (500 and 750 μg/mL), and cefotaxime (250 and 500 μg/mL) are used to clear the invitro environment of bacteria and have little effect on the elongation or bud formation from P. glauca embryos. Concentrations of hygromycin greater than 1 μg/mL and kanamycin greater than 10 μg/mL inhibited elongation, whereas concentrations of kanamycin greater than 5 μg/mL totally inhibited adventitious bud formation, callus formation, and caused seedling mortality. At concentrations as low as 1 μg/mL, kanamycin decreased adventitious bud formation by greater than 50%. These results suggest that effective selection of transformants expressing marker genes can be performed using relatively low concentrations of kanamycin or hygromycin.

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

HortScience ◽

10.21273/hortsci.33.3.478e ◽

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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