Callus Removal Research Articles

Callus Induction, Maintenance and Plantlet Regeneration in Creeping Bentgrass1

Callus induction, from mature caryopses, and callus maintenance and plantlet regeneration, using 14‐month‐old stock callus (SC), were investigated in Penncross creeping bentgrass (Agrostis palustris Huds.). Greatest callus induction occurred on Murashige and Skoog (MS) medium with 1.0 mg 2,4‐dichlorophenoxyacetic acid (2,4‐D) under light incubation and 1.0 or 10.0 mg 2,4‐D/1 under dark incubation. Kinetin supplements were not required for callus induction, however, caryopses incubated in the dark with 0.01 mg kinetin had greater callus formation than caryopses incubated without kinetin when combined with 1.0 mg 2,4‐D/1. Under dark incubation, caryopses produced the greatest callus yields (47 and 57 mg) and callus removal from caryopses required less time and effort. Callus induced from caryopses originated from the scutellum, root cortex and along the coleoptile up to and adjacent the first node. Callus growth using SC was greatest at 1.0 mg 2,4‐D/1. Callus previously cultured on 1.0 mg 2,4‐D maintained good plantlet regeneration capacity; whereas, callus previously cultured at 10 and 100.0 mg 2,4‐D/1 had poor and no plantlet formation, respectively. The best combination for shoot and root development in SC occurred at 0.10 mg and 1.0 mg kinetin/1 without 2,4‐D. All plantlets were potted in a sand:peat (1:1) mix and maintained in a glasshouse. Callus induced plants were similar to seeded plants. Less than 1% of the plantlets formed were albino.

An adjustable clamp for use during plating and grafting procedures in the mandible

The following advantages are claimed for this device: a. The clamp is simple to use and is self-retaining. b. Bone ends can be held together for application of bone plates or insertion of intraosseus wires. They can also be held separated while a bone graft is fixed between them. c. Its size does not require larger than normal skin incisions. d. The clamp can be used at any site on the mandible, and has been used on the ascending ramus, angle, body and symphysial regions. e. It proved particularly useful in a case where, due to a severe head injury, treatment was delayed and the fractured ends of the mandible had overridden and partially united. Using the clamp, it was possible to maintain separation while removal of callus was carried out, prior to reduction and fixation with intraosseus wires.