Adult leaves of grapevine cuttings stimulate rhizogenesis

Research Not

Endogenous abscisic acid in juvenile and adult grape (Vitis vinifera L. cv. Pinot noir)

Research Not

In vitro morphogenesis of grapevine (Vitis vinifera L.) originated from anticipated or latent buds

While in outdoor-grown vines shoots originate from latent buds, grapevine shoots from microcuttings cultured in vitro are produced by the anticipated bud. The latter shoots show physiological and morphological features of juvenility. This study was carried out to obtain more conform in vitro grapevine shoots. Latent buds were induced to develop in vitro. Shoots produced by latent buds had more juvenile features than those produced by anticipated buds. New information on the control of juvenility of grapevines in vitro is presented

Physiologie de la croissance chez la vigne: Influences foliaires

Les influences observées dans ces différentes expériences peuvent être classées en deux catégories, effets trophiques et effets morphogénétiques.Du point de vue trophique nous apportons la preuve expérimentale d'un fait essentiel jusqu'alors seulement soupçonné, la possibilité de mobilisation des réserves glucidiques de la souche par les parties végétatives des pousses lorsque l'activité photosynthétique est déficiente et ce pendant toute la durée d'un cycle végétatif.Deux autres faits sont confirmés: l'effet dépressif de la réduction de la surface foliaire assimilatrice sur l'évolution des grappes mais aussi la possibilité pour toutes les grappes d'un cep d'accéder à un «pool» commun des assimilats et ce, quelle que soit leur situation vis à vis des feuilles.Les résultats acquis par ces expériences nous ont permis de faire une première approche de certaines influences morphogénétiques de la feuille chez la vigne: influence foliaire sur la croissance internodale,participation des feuilles à l'arrêt de croissance des pousses à la fin du cycle végétatif,influence inhibitrice des feuilles adultes portées par un rameau donné sur le bourgeon terminal d'une pousse voisine privée de la totalité de ses feuilles. Cette influence est telle qu'elle conduit à la mort du bourgeon et finalement de toute la pousse défoliée.Shoot growth on grapevines in the presence or absence of leavesIn experiments with vines of cv. Pinot noir, ail or half the shoots per vine were continuously defoliated from bud burst onwards and compared with shoots on vines without defoliation. The two methods of defoliation gave different responses.Defoliation of ail shoots per vine reduced shoot length because of shorter internodes although leaf initiation continued for longer and at a rate comparable to that of shoots on control vines. The flowers on the defoliated shoots failed to set.Defoliation of only half the shoots per vine caused the defoliated shoots to die back to the nodes that carried inflorescences. Their flowers set and developed into mature but somewhat smaller berries. On these vines, the presence of mature leaves nearby was responsible for the behaviour of the defoliated shoots

Zone d'abscission et coulure de la vigne

Abscission zone and berry drop in grapevineBerry drop (coulure) in grapevine has various causes, but is generally observed in the days following anthesis and the separation occurs at the base of the flower pedicel. At this part of the pedicel a structured zone composed of little cells is observed where active abscission takes place. The abscission zone is activated by ethylene. This response does not only depend on the concentration of ethylene but also on the developmental stage of the target cells, which are highly reactive only during a few days. The presence of such an abscission zone in grapevine led us to consider new research to manage fruit set and thinning

Endogenous polyamine concentrations in juvenile, adult and micropropagated grapevine (Vitis vinifera L. cv. Pinot noir)

Research Not

Roles of leaf in regulation of root and shoot growth from single node softwood cuttings of grape ( Vitis vinifera )

The role of leaf in regulation of root and shoot growths in single node softwood cuttings of grape ( Vitis vinifera ) was characterised. Leafy cuttings showed early rooting, vigorous root growth and subsequent shoot development. Defoliation at planting induced early sprouting, but adversely affected rooting and decreased the survival of cuttings irrespective of pre-planting treatment with 100 ΜM indole 3-acetic acid (IAA). Treatment with IAA did not affect the percent rooting of leafy cuttings but increased root and shoot growth. Leaf weight (wt) and leaf area of the cuttings showed a highly significant correlation to root wt of the new plant at 4 wk after planting, while cutting stem + petiole wt was either not or less significantly correlated to root and shoot weights of the subsequent plant. The greater the area or wt of leaf, the better the root and shoot growths, implying that leaf contributed to adventitious root growth. However, retaining the leaf for just 2 days was enough to stimulate rooting in more than 80% of the cuttings, suggesting that leaf tissue could also induce root formation. Root growth increased with the period of leaf retention but leaf removal before 3 wk triggered sprouting leading to high mortality in rooted cuttings. Bringing the leaf closer to the rooting zone by preparing leaf at base (LAB) cuttings delayed rooting and sprouting compared with the standard leaf at top (LAT) cuttings. An inhibitory effect on rooting and sprouting by the exposed upper internode region in LAB cuttings is suggested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65538/1/j.1744-7348.2004.tb00313.x.pd