Rapid adventitious shoot regeneration from leaf explants of European birch

Abstract

The goal of this research was to develop a rapid and efficient system for regenerating shoots from leaf explants of European birch, Betula pendula Roth. Single-node stem explants were established in culture, and microshoots were subcultured every 4 weeks through 12 subcultures. Leaves from glasshouse plants or subcultured shoots were excised from stems, cut into approximately 35-mm 2 pieces, and placed on Woody Plant Medium (WPM) containing different combinations of naphthaleneacetic acid (NAA) (0, 3, 6 or 9 ~M) and benzyladenine (BA) (0, 7.5, 15 or 22.5 p~M) in a 4 x 4 factorial design. The percentage of leaf pieces forming shoots and the number of shoots regenerated per explant were recorded after 4 weeks. Only media containing BA without NAA stimulated shoot formation on leaf explants. Fifteen micromolar BA induced the most shoots to form on leaf explants compared to 30, 45 or 60 ~M of this cytokinin. In addition, shoot regeneration was enhanced up to four-fold between the first and eleventh subculture. Over 90% of the leaf explants regenerated shoots with an average of 18 buds formed per explant for the eleventh subculture. Almost twice as many explants formed shoots if their adaxial side was in contact with the medium rather than oriented away from it. The ability to regenerate shoots from leaves varied among plants, regardless of stock plant age. This reliable shoot regeneration system can be used for rapid shoot proliferation and potentially for genetic engineering of European birch.

Thidiazuron induces shoot organogenesis at low concentrations and somatic embryogenesis at high concentrations on leaf and petiole explants of African violet (Saintpaulia ionantha Wendl.)

“…Regeneration via shoot organogenesis from various types of explants, including leaf discs, petioles, petals, and anthers, with plant growth regulators such as IAA, NAA, BA and kinetin have been described in African violets (Bilkey and Cocking 1981;Harney and Knop 1979;Lo 1997;Start and Cumming 1976;Vazquez et al 1977). In a number of plant species, the in vitro morphogenic response is influenced considerably by the type of explant (Brand and Lineberger 1992;George and Tripepi 1994;Leege and Tripepi 1993), the physiological state of the donor plant (Bonga and Von Aderkas 1992), and the combination of plant growth regulators in the medium (Skoog and Miller 1957).…”

Plant Preservative Mixture™ Can Affect Shoot Regeneration from Leaf Explants of Chrysanthemum, European Birch, and Rhododendron

“…The medium for chrysanthemum leaves contained 0.3 µM benzyladenine (BA) and 11.5 µM indole-3acetic acid (IAA) (Trigiano and May, 1992). Birch medium was supplemented with 15 µM BA (Leege and Tripepi, 1993). Rhododendron medium was woody plant medium (WPM) (Lloyd and McCown, 1980) containing 4.9 µM indole-3-butyric acid (IBA) and 73.8 µM N 6 Fig.…”

Technological advances in temperate hardwood tree improvement including breeding and molecular marker applications

“…Adventitious shoots of sycamore maple (A. pseudoplatanus) can be regenerated from zygotic embryo explants and plants acclimatized under high humidity (Wilhelm 1999). European birch (B. pendula) has been regenerated from leaf explants from a mature tree (Leege and Tripepi 1993). Immature and mature seeds were used for adventitious regeneration of plants of Fraxinus americana and F. excelsior (Bates et al 1992;Tabrett and Hammatt, 1992).…”