In vitro vegetative propagation of Vitis: Application of previously defined culture conditions to a selection of genotypes

A range of grapevine species, cultivars and hybrids was surveyed for their responses to in vitro micropropagation.21 genotypes were established in culture from shoot apices (apical dome plus 2- to 4-leaf primordia) with a method previously developed for the Vitis hybrid Rougeon. However, this method proved to be inadequate for the establishment of the hybrid Seyval.Shoots grew on for 21 genotypes using a medium previously devised for the Vitis hybrid Remaily Seedless. Cultural conditions were inadequate for 4 of these genotypes. 10-h days resulted in best shoot production for 3 genotypes and 16-h days for 1. In general, shoot production was better or equal with short days than it was with long days. Shoots were multiplied from 3- to 4-node shoots (1.5 cm long) obtained in vitro. For the first 5 subcultures, 17 genotypes were multiplied on the medium used for first shoot production. Best results were obtained with Remaily Seedless which produced 13 shoots of at least 3 nodes, per subculture shoot after 2 months in culture. The 6th subculture employed the C2D salts which had previously been devised to improve shoot multiplication of Remaily Seedless. Yields were increased from 31 % to 350 % for all genotypes except V. labruscana Catawba which died in culture. For the rooting of subcultured shoots, a medium which had previously been developed for that purpose on Remaily Seedless was used successfully on 15 genotypes.Multiplication végétative de la vigne in vitro:Application des conditions de culture définies auparavant pour une sélection de génotypesLa multiplication végétative in vitro a été réalisée pour une collection d'espèces, de cultivars et d'hybrides du genre Vitis. 21 génotypes furent mis en culture à partir d'apex de 2 à 4 ébauches foliaires, par une méthode que nous avions développé pour l'hybride Rougeon. Ces conditions de culture n'ont pas été favorables â la croissance de l'hybride Seyval.La production de pousses herbacées fut obtenue pour ces 21 génotypes sur un milieu nutritif que nous avions défini pour l'hybride Remaily Seedless. Pour 4 génotypes les conditions de cultures n'ont pas été favorables. L'influence de la photopériode sur la production de pousses fut étudiée également. Les journées de 10 h bénéficièrent 3 génotypes et les journées de 16 h un seul. En général, la production en jours courts s'est avérée meilleur qu'en jours longs. La multiplication des pousses fut éffectuée par repiquage de boutures terminales obtenues in vitro et comprenant 3 à 4 noeuds (1,5 cm). Pour les 5 premiers passages la multiplication de 17 génotypes fut continuée sur le milieu de culture utilisé pour la production des premières ·pousses. Les meilleurs résultats ont été obtenus pour Remaily Seedless. En 2 mois chaque bouture apicale de ce cultivar a produit en moyenne 13 pousses ayant au moins 3 noeuds. Le 6e repiquage a été fait sur un milieu, C2D, développé auparavant pour améliorer la multiplication de Remaily Seedless. La récolte fut augmentée ainsi de 31 % à 350 % selon le génotype sauf pour V. labruscana Catawba qui s'est nécrosé.Pour l'enracinement de boutures apicales obtenues en culture, un milieu défini à cet effet pour Remaily Seedless fut utilisé avec succès pour 15 génotypes

In vitro propagation of Vitis: The effects of organic substances on shoot multiplication

The effects of organic substances on shoot multiplication from subcultured shoots of the Vitis hybrid Remaily Seedless were investigated. Culture media contained the inorganic nutrients of MURASHIGE and SKOOG (1962).Benzylaminopurine (BAP) was most effective in promoting shoot multiplication at 5 μM. 60 % of the shoots had at least 3 nodes (1.5 cm total length), a size considered adequate for micropropagation.The addition of adenine sulfate from 2.5 to 20 x 10 - 4 M depressed shoot multiplication when BAP was optimal.Combinations of thiamine (2 and 4 μM) and inositol (50; 100; 500 μM) were tested. Shoot multiplication decreased with increasing inositol concentration and was higher with 4 μM of thiamine. Best multiplication was with 4 μM thiamine and 50 μM inositol and gave similar number of shoots per explant as obtained on our standard medium which contains in addition nicotinic acid and pyridoxine. However, twice _as many 3-node shoots were produced on the standard medium.The amino acids arginine, aspartate, asparagine, glutamate, glutamine and tyrosine at 2.5-40 x 10 - 4 M had no effect on shoot multiplication.With the culture conditions used in this research, an adequate set of organic constituents for shoot multiplication of grapevines is defined as 3 μM thiamine · HCl, 55.5 μM myo-inositol, 8 μM nicotinic acid, 5 μM pyridoxine · HCl and 5 μM benzylaminopurine. The addition of 4 μM of aspartate may be beneficial. It was found that optimization of vitamin concentration is important in shoot multiplication. The restricted Optimum cytokinin concentration for best shoot production suggests that its concentration may have to be adjusted for each cultivar

EMCCDs for space applications

This paper describes a qualification programme for Electron-Multiplication Charge Coupled Devices (EMCCDs) for use in space applications. While the presented results are generally applicable, the programme was carried out in the context of CCD development for the Radial Velocity Spectrometer (RVS) instrument on the European Space Agency's cornerstone Gaia mission. We discuss the issues of device radiation tolerance, charge transfer efficiency at low signal levels and life time effects on the electron-multiplication gain. The development of EMCCD technology to allow operation at longer wavelengths using high resistivity silicon, and the cryogenic characterisation of EMCCDs are also described

Effect of time of thinning on berry size of girdled, gibberellin-treated 'Thompson Seedless' grapes

Gibberellin-treated 'Thompson Seedless' grapes were thinned at initiation of berry shatter following bloom or at 1 to 6 weeks thereafter. The results indicate that for maximum increase in berry size, thinning should be done during fruit-set or as soon after as possible.Der Einfluß des Ausdünnungstermins auf die Beerengröße von geringelten, gibberellinbehandelten „Thompson Seedless"-TraubenGibberellin-behandelte „Thompson-Seedless"-Trauben wurden bei Beginn des Durchrieselns oder 1-6 Wo chen danach ausgedünnt. Die Ergebnisse zeigen, daß für einen maximalen Zuwachs der Beerengröße das Ausdünnen während des Fruchtansatzes oder sobald wie möglich danach erfolgen sollte

Chemical thinning of grape clusters (Vitis vinifera L.)

Twelve thinning compounds were tested at 0.1 to 4,000 ppm on 'Carignane' and 'Thompson Seedless' clusters at 4 developmental stages (prebloom, bloom, fruit-set, and 2 weeks after fruit-set). Clusters were usually least sensitive to the compounds ut post fruit-set and, in general, 'Thompson Seedless' was more sensitive than 'Carignane'. On 'Thompson Seedless' the morphactin IT 5733 had a wider activity range than IT 5732 or IT 4433. Potassium iodide reduced set when applied at prebloom or bloom. Ethephon was usually effective at some concentration at all growth stages. Ascorbic acid, iso-ascorbic acid, and Pennthin usually were not significantly effective in thinning either cultivar.The 3-CPA had a wide range of activity on both cultivars at most stages of growth, and this compound at 10 ppm reduced number of berries at bloom and fruit set for 'Carignane' and 'Thompson Seedless', respectively. Iodoacetic acid at 1,000 ppm was effective in reducing number of berries in both cultivars at all growth stages. The 4-CPA at 100 ppm was effective at prebloom stage en 'Carignane', and .'.lt bloom on 'Thompson Seedless'. Salicylic acid at 1,000 ppm effectively reduced number of berries of each cultivar when applied at fruit-set stage

Response of Thompson Seedless grapes to prebloom thinning

Paired treatments with and without application of GA at bloom were applied to Thompson Seedless vines that were cluster-thinned at prebloom, and berrythinned at shatter, cluster-thinned and berry-thinned at prebloom, or cluster-thinned and berry-thinned at shatter stage following bloom. Unsprayed clusters from vines that were cluster-thinned at prebloom or cluster- and berrythinned at prebloom stage were very compact. All combinations of thinning that included applications of GA at bloom produced clusters that were looser than the corresponding unsprayed clusters. GA increased berry size, and clusters that received GA usually had fewer shot berries than did corresponding unsprayed clusters. Prebloom thinning increased the number of berries per cm. of lateral, but applications of GA at bloom greatly decreased the amount of set. A reduction of flower shatter occurred as a results of prebloom thinning

Influence of cluster exposure on fruit composition and wine quality of Seyval blanc grapes

Experiments were conducted in 1981 and 1982 to investigate the influence of duster exposure on fruit composition, wine quality, and incidence of bunch rot (Botrytis cinerea PERS.) of the French-American hybrid grape cultivar Seyval blanc. Berry sampling from 4 exposure categories (western exposure, eastern exposure, partial shade, and full shade) indicated highest °Brix, pH and tartrate, and lowest titratable acidity (TA) and malate in the exposed fruit post veraison. Total acidity and malate were highest in exposed fruit between fruit set and veraison. Exposure of the fruit also reduced the incidence of bunch rot during the 1981 season. Wine quality differences were small and not statistically significant, although wines vinted from exposed fruit tended to score higher. Canopy management practices that optimize fruit exposure would be helpful in maximization of fruit and wine quality

Relation of plant regulators to bud rest in Vitis vinifera grapes

A large varietal difference was noted in time required for grape buds to terminate rest. 'Pearl of Csaba' and seedless varieties terminated rest most rapidly. Exogenous applications of benzyladenine (BA) at 1000 ppm or of N-dimethylamino succinamic acid (B-9) at 2000 ppm hastened termination of rest. Benzothiazole-2(-oxyacetic acid (BOA) at 1000 ppm and 2-chloroethyltrimethylammonium chloride CCC) at 200 or 2000 ppm markedly delayed it.In cuttings of 'St. Emilion' treated with exogenous BA, much inhibitor disappeared from the treated buds within 10 days after treatment. We suggest that the effect of BA in terminating rest may be due to its destructive effect on inhibitor concentration in the bud.Inhibitory substances were present in buds from 'St. Emilion' from December 5 through the dormant season. The compounds disappeared and stimulatory activity increased at the start of shoot growth

Use of differential thermal analysis to quantify bud cold hardiness of grape selections and clones

Differential thermal analysis (DTA) was used to characterize primary bud mid-winter cold hardiness of Vitis spp. Bud hardiness reached a maximum and was rather stable during the months of January and February at Geneva, New York. Because cold tolerance increases during periods of prolonged cold, observed freezing temperature was adjusted on the basis of the freezing temperature of cv. Concord on the day of observation. DTA gives reproducible and meaningful estimates of bud freezing temperature. Such data account for at least 50 % of the among-cultivar variance in overall vine cold hardiness