Abstract (EN):
An efficient protocol was developed for large-scale micropropagation of slash pine (Pinus elliottii Engelm. var. elliottii). For that, explants consisting of shoot apices 1.5-2.0 cm in length from 4 wk-old seedlings were cultured on two different basal media (Murashige & Skoog (MS) and Westvaco WV5 (WV5)). All media were supplemented with 6-benzylaminopurine (BAP), to stimulate the formation of axillary buds. Best bud induction was achieved, after 4 wk, on Westvaco WV5 medium (with 10-mu M BAP) with rates close to 100%, and an average number of similar to 7 new buds formed per explant. Elongation took place for 6 wk on Westvaco WV5 medium containing activated charcoal (0.2% (w/v)) and without growth regulators. Rooting took place on half-strength Westvaco WV5 medium containing 9.8-mu M indole-3-butyric acid (IBA). After 6 wk, root primordia were visible in similar to 43% of shoots. The acclimatization protocol was also optimized by controlling relative humidity, light/photoperiod, temperature, and nutrition, which led to an acclimatization success of similar to 89%. Flow cytometry analysis of DNA-ploidy did not show any variation between micropropagated plants and seedlings. With the protocol here described, it is possible to obtain a high number of genetically uniform plants per explant, 1 yr after in vitro germination of slash pine seeds.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
9