Evening primrose (Oenothera biennis L.) is a wild flower with high and valuable oil content. High seedshattering, indeterminate inflorescence and heterogeneous germination limit the commercial cultivation ofthis plant. Besides agronomical research, breeding programs can also remedy the above mentioned problems.Since traditional breeding methods take a long time, using techniqu...

Excised lettuce (Lactuca sativa L. cv. Arctic) hypocotyls retain the ability to elongate in response to exogenously supplied gibberellic acid and gibberellin A(1) (GA(1)). We have studied the relationship between metabolism of GA(1) and elongation in this tissue. In 24 hours at 28 C, hypocotyls treated with 3 mum GA(1) double in length while controls elongate less than 45%. After an exogenous h...

Depending on host-pathotype combination, two types of sunflower-Plasmopara halstedii incompatibility reactions have previously been identified. Type I resistance can restrict the growth of the pathogen in the basal region of the hypocotyls, whereas type II cannot, thus allowing the pathogen to reach the cotyledons. In type II resistance, a large portion of the hypocotyls is invaded by the patho...

We investigated the roles of cortical microtubules in gravity-induced modifications to the development of stem organs by analyzing morphology and orientation of cortical microtubule arrays in hypocotyls of Arabidopsis (Arabidopsis thaliana) tubulin mutants, tua3(D205N), tua4(S178Delta), and tua6(A281T), cultivated under 1g and hypergravity (300g) conditions. Hypocotyls of tubulin mutants were s...

We investigated the effects of various concentrations of diethyl aminoethyl hexanoate (DA-6) on the regeneration and growth of adventitious buds in in vitro purple coneflower cultures. Among the 3 types of explants tested, leaf explants required higher concentrations of DA-6 than petiole and root explants in order to obtain high regeneration rates, while root explants required the lowest concen...

When etiolated radish (Raphanus sativus var. hortensis f. gigantissimus Makino) hypocotyls were subjected to a continuous unilateral illumination with white fluorescent light (0.1 watt per square meter), the growth rate at the lighted side was strongly inhibited for the first 2 hours, while that at the shaded side showed no change. After 2.5 hours growth on the lighted side recovered gradually,...

Explants of tobacco pith taken at various distances from the apex of a mature stem show a sharp gradient in growth potential in vitro; growth is highest in the extreme apical and basal explants, and is minimal in explants removed ca. 75 cm from the apex. Calluses produced by the vigorously growing basal explants are harder and more compact than those produced from more apical explants. The grad...

the present work developed an efficient plant regeneration and propagation system via direct organogenesis for morinda officinalis how., a valuable endangered medicinal plant. the effects of explant types on shoot induction, plant growth regulators on shoot proliferationand elongation and the subsequent rooting ability of shoots were examined. among the various types of explant, direct shoot pr...

Two explants of shell were removed from each of several fertile eggs of domestic fowl at different times during incubation. The chorioallantoic membrane (CAM) was removed from one of the explants (SHELL ONLY) and was left in situ on the other (SHELL+CAM). Explants were cultured for 24, 48 or 96 h at 37 degrees C and 5% CO2 in air in individual Petri dishes containing Dulbecco's modified Eagle's...