Search results for "Apical dominance"
showing 6 items of 6 documents
Hormonal and carbohydrate control of fruit set in avocado ‘Lamb Hass’. A question of the type of inflorescence?
2021
[EN] The avocado tree (Persea americana Mill.) has two types of shoots, indeterminate, which maintain vegetative development from an apical bud, and determinate, which do not have vegetative growth. Indeterminate shoots set fewer fruits than determinate ones, and significantly hasten physiological fruitlet abscission. The competition between vegetative and flower development is accepted as the most reasonable hypothesis to explain the differences. However, our results show that from anthesis until fruit set flowers of indeterminate inflorescences, both those remaining on the tree and those abscised, had a higher sucrose and C6 carbohydrate content than flowers of determinate ones and no dif…
Foliar influences on the vegetative development of grapevine
1997
<p style="text-align: justify;">Various defoliation treatments were applied to grapevine shoots during the whole duration of the growth period: full defoliation of every shoot of vine, defoliations retaining a various number of adult leaves to the base of every shoot and defoliations retaining a various number of young leaves to the top. The effects of these treatments allow to identify the major foliar influences on the vegetative development. Total defoliation induced a lesser intemodal elongation. This result is probably due, in part, to a carbohydrates deficiency consecutive to this drastic treatment. The defoliations with variation of the number of young leaves showed that the le…
In vitro multiplication ofVella lucentina M. B. crespo (Brassicaceae), a threatened Spanish endemic species
1995
Vella lucentina M. B. Crespo is a threatened Spanish species that is endemic to a small area in eastern Alicante Province (SE Spain). Micropropagation techniques were applied forex situ conservation of this plant. Aseptic epicotyls bearing the apical bud were grown in Murashige and Skoog medium supplemented with 6-furfurylaminopurine (Kin), N6-benzyladenine (BA) or 6-(γ,γ,-dimethilalylamino) purine (2iP). High multiplication rates were obtained with 0.5, 1, or 2 mg·liter−1 BA, or 1 or 2 mg·liter−1 2iP. Indole-3-acetic acid and indole-3-butyric acid were utilized for rooting in half-strength Murashige and Skoog medium. Regenerated plants were transferred to a potting mix and gradually acclim…
Demonstration of a correlation between young leaves, apex and young bunches specific to a young grapevine cutting in the first period of its developm…
2001
<p style="text-align: justify;">The development of hardwood cutting of grapevine comprise 4 succesive phases. Phase I: first period of shoot extension. Phase II: characterized by a slow growth due to a very low activity of the terminal bud. Phase III: reactivation of the growth consecutive to a resumption of the apical activity. Phase IV: when the growth becomes maximal.</p><p style="text-align: justify;">The objective of this work has been to identify the cause of the slowdown of the activity of apical bud during the phase II.</p><p style="text-align: justify;">In a first experiment, we have compared the effects of three modes of defoliation applied from the b…
In vitro propagation ofSalix tarraconensis Pau ex Font Quer, an endemic and threatened plant
1996
Salix tarraconensis Pau ex Font Quer, an endemic willow species from northeast Spain, was micropropagated with nodal segments. Shoot multiplication was obtained with different cytokinins, either on Murashige and Skoog medium or woody plant medium. Best results for shoot formation were obtained on Murashige and Skoog medium containing 4.9 μM of 6-γ-γ-dimethylallylaminopurine. Shoots showed strong apical dominance, and some cultures displayed apical necrosis. Benzyladenine gave the worst results; shoots displayed very slow growth, deformed leaves, and hyperhydrity. Good rooting of shoots was obtained with different auxins or without plant growth regulators on woody plant medium. The best resu…
Internodal elongation in the grapevine (<em>Vitis vinifera</em> L.) : leaf influences and role of the shoot apex
1996
<p style="text-align: justify;">The respective influences of the leaves and shoot apex on stimulation of internodal elongation were studied in the grapevine. Various defoliation or decapitation treatments were applied to the shoot of rooted hardwood cuttings grown in a controlled environment chamber.</p><p style="text-align: justify;">Concerning the foliar influences, the role of three sorts of leaves, in relation to their nodal position relative to the internode was analysed ; its own leaves, the leaves located below it and the young leaves neoformed above. The effects produced by excision of these different leaves show that the two adjacent leaves (below and above) of th…