Plantlet regeneration from fascicular buds of seedling shoot apices of Pinus roxburghii Sarg

Abstract

Shoot apices of Pinus roxburghii Sarg were cultured on Murashige and Skoog's medium (MS) supplemented with cytokinins 6-benzyladenine (BA), kinetin and N-benzyl-9-(2-tetrahydropyranyl) adenine (BPA) alone and in combination with auxin, -napthaleneacetic acid (NAA). Of the three cytokinins tested at varying concentrations, medium supplemented with 10 μM BA was found optimal in respect of explant responsiveness (97.22 %) and average number of buds induced per explant (7.42). The concentration of cytokinins in the induction medium had a profound effect on rate of elongation of induced buds on MS basal medium containing 0.5 % activated charcoal. Further, shoots induced on lower concentrations of BA increased up to 2.4 times in length in 4 weeks. Decapitation of the explant enhanced the rate of axillary bud elongation. Proliferating shoot cultures were established by sub-culturing the axillary shoots on MS supplemented with 10 μM BA. Shoots 2 -3 cm in length were suitable for culturing as more buds were induced on them compared to longer or shorter shoots. Root primordia were induced on 70.83 % shoots when transferred to ½ MS medium supplemented with 5.0 μM NAA. Elongation of root primordia (60 %) was achieved in liquid ½ MS basal medium. The plantlets were successfully transferred to soil after hardening; the time period from initiation of shoot buds to transplantation being 20 -22 weeks.

In vitro direct organogenesis and regeneration of Medicago sativa

“…Five days later, many adventitious shoot buds were induced from previous axillary meristems of explants ( Fig 1D). Similar to our results, Kalia et al (2007) reported that removal of the elongated axillary shoots at regular intervals was necessary to allow the elongation of smaller buds. It suggested that the foregoing failure on the induction of adventitious buds may be partially attributed to the growth of these axillary shoots, which could inhibit the formation of adventitious buds by plant apical dominance.…”

Adventitious rooting performance in micropropagated Cornus mas

“…In the course of ex vitro rooting of C. nuttalli, about 53 % of shoots could be rooted by using 4.5 % IBA (Edson et al 1994). In the case of in vitro rooting of C. florida microshoots, a 52 % frequency was recorded with 2.5 µM IBA and a 46 % frequency with 4.9 µM IBA (Kaveriappa et al 1997). Results with in vitro rooting of C. mas cv.…”

“…Micropropagated plantlets were regenerated either via axillary shoot proliferation (Kaveriappa et al 1997) or somatic embryogenesis (Trigiano et al 1989). Attempts were also aimed at micropropagation of other Cornus species, including C. nuttalli (Edson et al 1994), C. canadensis (Pennell 1983) or ornamental cultivars of C. kousa (Hadziabdic et al 2004).…”

Short Communication. An efficient axillary shoots propagate system for the living fossil plant - Wollemi pine (Wollemia nobilis)

“…The percentage of shoot regeneration and rooting plants of Wollemia nobilis remained low compared to reports for micropropagated plants of other gymnosperm (Kalia et al, 2007). The main difficulty for the implementation of this regeneration procedure is in the initial bud browning and root induction.…”