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

Short communication: Rapid in vitro tests to determine the toxicity of raw wastewater and treated sewage effluents

Wastewater consists of a complex mixture of substances. During wastewater treatment these harmful substances can be eliminated or degraded. However, persistent compounds released with the treated sewage effluents enter the environment and pose a risk to animal and human life. To determine the potential risks involved, screening tests are needed to monitor wastewater for potential toxic contaminants. The aim of this study was to validate and use screening tests to determine the toxicity of raw wastewater and treated sewage effluents from 3 sewage treatment plants in the Western Cape, South Africa. Raw wastewater and treated sewage effluents were screened for cytotoxicity using lactate dehydrogenase (LDH) release from cells as biomarker, for neurotoxicity using acetylcholinesterase (AChE) inhibition and for genotoxicity using the Save Our Soul (SOS) test. Results showed no cytotoxicity for both raw wastewater and treated sewage effluents from all sewage treatment plants. Raw wastewater from all sewage treatment plants contained AChE inhibitors and sewage treatment processes were not effective at eliminating these AChE inhibitors. Raw wastewater from all sewage treatment plants tested positive for genotoxicity. Treated sewage effluents from all three sewage treatment plants displayed no genotoxicity indicating effective removal of genotoxins by all three sewage treatment plants investigated