M. Y. Hossain

Plant regeneration from nucllar tissues of Aegle marmelos through organogenesis

A protocol for organogenesis from nucellar explants excised from fertilized ovules of immature fruits of Aegle marmelos Corr. was developed. Adventitious buds were initiated on Murashige and Skoogs (MS) medium containing various combinations of 6-benzyladenine (BA), α-naphthalene-acetic acid (NAA), 3-indoleacetic acid and gibberellic acid. Medium containing 4.4 μm BA and 2.7 μM NAA produced the maximum number of adventitious buds per explant. Shoots were elongated by transferring explants with shoot buds to medium with a low concentration of BA (0.44 μM). Rooting of in vitro-regenerated shoots was obtained in half-strength MS medium with 4.9 μM indole-3-butyric acid. This is the first report of plant regeneration from nucellar explants of A. marmelos.

Micropropagation of Morus laevigata Wall. from mature trees.

Multiple shoots were obtained from nodal explants of 10-year-old tree of Morus laevigata on Murashige and Skoogs medium supplemented with different concentrations (0.5–5.0 mg.l−1) of benzyladenine (BA). Nodal segments taken from in vitro proliferated shoots gave further multiple shoots when cultured on the same basal medium containing 2.5 mg.l−1 BA. Repeated subculture resulted in rapid shoot multiplication at the average rate of 6-fold per subculture. In vitro raised shoots rooted on MS medium containing 0.1 mg. l−1 each of 3-indolebutyric acid (ISA) and α-naphthaleneacetic acid (NAA). The regenerated plantlets were successfully established in soil under field conditions after a few days of indoor acclimatization.

Production of plantlets from Aegle marmelos nucellar callus

Techniques have been developed for the regeneration of Aegle marmelos from nucellar explants. Slow-growing calli were induced from nucellar explants excised from 90–120 d-old developing fruits. The medium consisted of Murashige and Skoog formulation containing 40 g/l sucrose, 400 mg/l casein hydrolysate, 5 mg/l 1-naphthaleneacetic acid and 1 mg/l kinetin. The basal medium with high concentration (1–5 mg/l) of N6-benzyladenine (BA) and low concentration (0.1 mg/l) of NAA was suitable for regeneration of shoots from 3-month-old calli. Addition of 1 mg/l gibberellic acid (GA3) favoured shoot growth. Callus-derived shoots produced roots and developed into plantlets when transferred to half-strength MS medium supplemented with 0.5 mg/l indole-3-butyric acid (IBA) and 0.5 mg/l NAA. Approximately 5 months were required for the full regenerative process.

Effects of media composition and culture conditions on in vitro rooting of rose

Abstract Basal medium strength, auxins, sucrose, agar, pH, photoperiod and culture room temperature substantially affected the development of roots from proliferated rose (cultivar ‘Tajmahal’) shoots. Half strength Murashige and Skoog (MS) medium fortified with 0.1 mg l−1 naphthaleneacetic acid (NAA) and 0.5 mg l−1 indolyl-3-acetic acid (IAA), sucrose level of 40 g l−1, agar concentration at 6 g l−1, a 16 h photoperiod and 28°C culture room temperature were required for optimal in vitro rooting of the excised shoots. Gradual acclimatization was essential for subsequent establishment of plantlets in natural condition.

High efficiency plant regeneration from petiole explants of Carica papaya L. through organogenesis

Callus cultures were obrained from petiole explants of Carica papaya on MS medium containing 0.5–10.5 μM α-naphthaleneacetic acid (NAA) in combination with 0.5–5 μM benzyladenine (BA). Hard-green calli were transferred to MS medium containing 100 mgl−1 casein hydrolysate (CH) with specific BA-NAA formulation, where they developed adventitious buds within 2 weeks of culture. Maximum number of adventitious buds were obtained in 2 μM BA and 0.1 μM NAA. Shoot regeneration occurred from these adventitious buds by the end of the 4th week. Regenerated shoots were elongated in hormone-free medium and rooted in half-strength MS fortified with 3 UM NAA and 0.5 μM gibberellic acid (GA3). The regenerants were transferred to soil after acclimatization.

Adventitious shoot regeneration from root tips of intact seedlings of Aegle marmelos

SummaryIntact seedlings of Aegle marmelos Corr. were tested for their ability to produce adventitious shoots by direct culture of mature seeds on Murashige and Skoog (MS) medium supplemented with different concentrations of benzyladenine (BA); 1–2 mg l–1 BA was found to be the optimum concentration. Addition of 0.1 mg l–1 indoleacetic acid (IAA) further increased shoot proliferation efficiency. Shoot buds originated from regions adjacent to the bases of cotyledons and cotyledonary axils and roots. In many cases, adventitious shoots were produced from the enlarged apical region of root. Shoots were rooted on MS medium supplemented with indolebutyric acid (IBA). Rooted plantlets were successfully established in soil.

Micropropagation of Aegle marmelos Corr. (Bael)

Aegle marmelos, Corr., commonly known as bael, is medium-sized slow-growing deciduous spiny woody fruit tree of the tropics (Fig. 1). It belongs to the family Rutaceae, in which polyembryony is a common phenomenon (Melchior 1964; Rangaswamy 1981). Its flowers are sweet-scented and bloom during the spring. It takes 10–12 months from flowering to fruit ripening. Fruits are large, globose, ovoid or pyriform, green when unripe and turn yellow-brown when ripe. Seeds are embedded in aromatic, sweet, thick pulp. The testa is woody and the seeds are oblong, compressed; the embryo has a thick fleshy cotyledon.