Presence Of Growth Regulators Research Articles

In vitro biocontrol activity of Trichoderma harzianum on Alternaria alternata in the presence of growth regulators

EJB Electronic Journal of Biotechnology ISSN: 0717-3458 Vol.4 No.2, Issue of August 15, 2001© 2001 by Universidad Catolica de Valparaiso -- Chile Received November 30, 2000 / Accepted April 23, 2001

Inositol 1,4,5-trisphosphate distribution in Lycopersicon esculentum Mill seedlings cultivated "in vitro" under different conditions.

Measurements of inositol 1,4,5-trisphosphate (Ins1,4,5-P3) in cotyledons, epicotyls and roots of tomato seedlings grown "in vitro" either in the light or in the dark indicated that higher concentrations of this signal-transducing molecule are contained in hypogeous vs. epigeous tissues. The same was observed in induced cotyledon explants grown in the light in the presence of growth regulators. Data concerning phosphatidylinositol metabolism in seedling roots are also reported. Taken together, our results may be helpful in understanding the role of the polyphosphoinositide signal system in plants.

Lipid Content and Pigments of Flax Stems Grown and Retted in Various Conditions

Abstract The effects of cultivar, nitrogen level, presence of growth regulator and retting process on the lipids and pigments of flax fibre were examined. The flax straw was field, water or enzymatically retted. The lipids were extracted from the retted and scutched flax fibre, weighed and analysed qualitatively by thin layer chromatography (TLC). The pigments were examined spectrophotometrically from the lipid extract. The effect of the retting process on the lipid content and pigments of flax fibre was significant. Enzymatic retting produced the most lipid-rich fibre compared with the traditional retting processes. The effects of other variables were negligible. Qualitative differences were not detected by TLC

Androgenesis of the salt tolerant shrub Atriplex glauca

Clusters of flowers, 4 to 5 days old, were successfully cultured on Nitsch and Nitsch (1969) medium in the presence of growth regulators. An average of 20 plants per explant were produced after 6 weeks. Organized growth was obtained only from flowers collected during spring or early summer. Microscopic observations during shoot regeneration indicated that shoot organogenesis took place directly from microspores to give rise to shrubby plants. Their subsequent transfer onto fresh medium in the presence of a different set of growth regulators resulted in the production of "haploid" and "diploid" lines in the proportion of 50∶50. The presumed haploid plants were successfully rooted on Woody Plant Medium (Lloyd and McCown 1980) within a week. The significance of androgenic lines for the study of salt tolerance and the genetic improvement of Atriplex forage quality is discussed.

Radioimmunoassay of Morphinan Alkaloids in Papaver somniferum Hypocotyls, Callus, and Suspension Cultures

Summary Hypocotyls of poppy ( Papaver somniferum L. cv. Marianne) were assayed for morphinan alkaloid content using a commercially available radioimmunoassay (RIA) for morphine (Abuscreen, Roche Diagnostics). The hypocotyls showed a sharp rise in morphinan alkaloid content on day 3 following sowing, reachin a plateau (9 ng·mg- 1 fresh wt) between day 4 and day 5. Hypocotyl explants were cultured for up to 2 months on solid nutrient medium containing α-naphthaleneacetic acid. During this time and while hypocotyls formed callus, the morphinan alkaloid content fell to a «maintenance» level of 0.4 ng·mg −1 fresh weight in culture. Callus masses retained laticifer-like cells. If cell suspensions were plated with medium lacking growth regulators, plantlets were regenerated and the level of alkaloids found for hypocotyls was re-established. If plated cell suspensions were cultured in the presence of growth regulators, organs formed, but plantlets did not regenerate and the alkaloid content remained at or near the maintenance level. Over a period of a year callus subcultures lost their laticifer-like cells, their embryogenic potential, and their ability to maintain low-level alkaloid production.

The presence of growth regulators during the early development of Fucus

The presence of growth regulators during the early development of Fucus

The Presence of Growth Regulators During the Early Development of Fucus

The Presence of Growth Regulators During the Early Development of Fucus