Applications of tissue culture to the genetic improvement of grapevines

The grapevine was among the first plants to be cultured in vitro (1944). Regeneration by somatic embryogenesis and organogenesis was reported in the 1970s and plantlet production from cell suspensions or callus is now a routine procedure in many laboratories. Methods for isolating grapevine protoplasts have yet to be achieved. The fragmented apex technique, involving high-frequency adventitious bud formation, is a novel and efficient method for rapid multiplication of grapevines but culture of anthers and pollen has been generally unsuccessful. Micropropagation procedures for vinifera grapes, Vitis species and interspecific hybrids, including rootstocks, are all available. Seedless-seedless hybridization, involving embryo rescue in crosses with stenospermocarpic female parents, is of major significance in breeding seedless table grapes. There has been substantial progress in protoplast cell, tissue and organ culture of grapevines, but this technology is still less well developed than with some other fruit crops (notably citrus and apples). So far, tissue culture has little impact on genetic improvement. Exploitation of somaclonal variation for clonal selection is an attractive option for premium wine cultivars. There is evidence of somaclonal variation in vitro but the usefulness of this random genetic variation in viticulture is still uncertain. To date, results of field trials with vines from somatic embryos have been disappointing. The grapevine is proving to be a difficult subject for Agrobacterium-mediated genetic transformation (A. tumefaciens and A. rhizogenes) and microprojectile technology is another option which is being investigated

Flowering in Vitis: Effects oi genotype on cytokinin-induced conversion oi tenddls into inflorescences

Tendrils of several Vitis species and hybrids were transformed into inflorescences by repeated treatment of shoot apices with 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine (PBA, 50-1000 flM). Tendrils of male vines were more readily converted into inflorescences by PBA-treatment than those of females or hermaphrodite vines. V. vinifera, V. rupestris and their hybrids were more responsive to PBA-treatment than V. monticola, V. girdiana and Muscadinia rotundifolia. Bunches of gmpes with viable seeds were produced by tendril-derived inflorescences of the V. vinifera cultivars Muscat of Alexandria (☿) and Katakourgan (♀) and of a V. vinifera X V. rupestris hybrid (♂).Die Blütenbildung bei der Rebe: Der Einfluß des Genotyps auf die Cytokinin-induzierteUmwandlung von Ranken in InfloreszenzenDie Ranken verschiedener Vitis-Arten und -Bastarde entwickelten sich zu Infloreszenzen, wenn die Triebspitzen wiederholt mit 6-(Benzylamino)-9-(2-tetrahydropyranyl)-9H-purin (PBA; 50-1000 pM) behandelt wurden. Die Ranken männlicher Reben ließen sich durch PBA-Behandlung leichter in Infloreszenzen umwandeln als diejenigen weiblicher oder zwittriger Reben. V. vinifera, V. rupestris und ihre Kreuzungen reagierten stärker auf die PBA-Behandlung als V. monticola, V. girdiana und Muscadinia rotundifolia. Trauben mit lebensfähigen Samen entstanden aus rankenbürtigen Infloreszenzen der V.-vinifera-Sorten Muskat von Alexandria,(☿) und Katakourgan (♀) sowie einer V.-vinifera- x V.-rupestris-Kreuzung (♂)

Organogenesis in internode explants of grapevines

Organogenesis was studied in cultured internodes of grapevine cultivars, hybrids and species. Adventitious root formation occurred with a wide range of media and genotypes. Adventitious buds were formed in explanrts grown in ag1tated liquid culture with NITscH medium supplemented with benzyladenine (1 μM) and 2,4-D (5 μM} or a mixture of 2,4-D and ß-naphthoxyacetic acid (5 μM). Bud formation occurred only in cultures derived from seedlings of Muscadinia rotundifolia, Gloryvine (Vitis vinifera L. x Vitis rupestris ScHEELE) and V. vinifera x Gloryvine, i.e. (Grenache x Cabernet Sauvignon) x Gloryvine and (Sumoll x Cabernet Sauvignon) x Gloryvine. Cuttings from mature vines of V. vinifera cultivars, or from clonal Gloryvine, gave explants which failed to produce buds. Results are discussed in relation to effects of composition of media, origin of explant, maturity of the mother plant and genotype.Organogenese bei Internodienexplaotaten von RebenBei Kalluskulturen aus Internodien verschiedener Rebsorten, -kreuzungen und -arten wurde die Organogenese untersucht. Adventivwurzeln bildeten sich auf zahlreichen Nährmedien und bei vielen Genotypen. Adventivknospen entstanden an Explantaten in Schüttelkulturen auf einem flüssigen Medium nach NITSCH mit einem Zusatz von Benzyladenin (1 μM) und 2,4-D (5 μM) oder einem Gemisch von 2,4-D und ß-Naphthyloxyessigsäure (5 μM). Knospen bildeten sich nur in Kulturen aus Sämlingen von Muscadinia rotundifolia, Gloryvine (Vitis vinifera L. x Vitis rupestris SCHEELE) sowie V. vinifera x Gloryvine, nämlich (Grenache x Cabernet Sauvignon) x Gloryvine und (Sumoll x Cabernet Sauvignon) x Gloryvine. Aus ausgereiftem Holz von V. -vinifera-Sorten oder einem Gloryvine-Klon hergestellte Stecklinge ergaben Explantate, die keine Knospenbildung zeigten. Die Ergebnisse werden im Hinblick auf die Zusammensetzung der Nährmedien, den Ursprung des Explantats, den Reifezustand der Mutterpflanze und den Genotyp diskutiert

Somatic embryo formation by cultured ovules of Cabernet Sauvignon grape: Effects of fertilization and of the male gameticide toluidine blue

Maximum numbers of pollen tubes were found in styles of plants growing at 27 °C (day) and 22 °C (night). Fertilization generally occurred by 24 h after anthesis. Treatment of both isolated pollen and inflorescences of intact vines with toluidine blue (10-100mg l-1) reduced pollen germination and tube growth. Pollen tubes which penetrated the styles of toluidine blue-treated flowers appeared to be abnormal. Somatic embryos were produced with equal frequency by nucellus tissue from cultured ovules from both normally-fertilized and toluidine blue-treated flowers. There was degeneration of embryosacs in all cultured ovules. The grape appears to be unresponsive to toluidine blue as an inducer of haploid parthenogenesis

Adventitious bud formation in leaf explants of some grapevine rootstock and scion cultivars

Die Bildung von Adventivknospen an Blattexplantaten einiger Unterlags- und Edelreissorten der RebeAdventivknospen bildeten sich am häufigsten an Blattexplantaten der Sorten Rupestris St. George, Thompson Seedless und Niagara (ca. 35-50 %), in mittlerer Häufigkeit bei Ramsey, Cabernet Sauvignon, Chardonnay und Concord (ca. 25-30 %), am wenigsten häufig bei 110-R und ARG 1 (20 % ). Explantate von Blattstielen waren im allgemeinen regenerationsfähiger als solche aus Blattspreiten. Die Art und Weise, in der die Mutterpflanzen kultiviert wurden (Klimakammer oder in vitro), wirkte sich später nicht auf die Bildung von Adventivknospen aus. Benzyladenin (10 μM) und a-Naphthylessigsiäure (0,05-0,10 μM) waren in Verbindung mit Cytokinin und Auxin für die Bildung von Adventivknospen am wirksamsten. An Blattspreiten-Explantaten wurden mehr Knospen gebildet (1-12) als an Blattstiel-Explantaten (1-6). Ein gleichbleibender Einfluß der Behandlung auf die Anzahl der Knospen je Explantat lag jedoch nicht vor. Der maßgebliche Faktor war der Prozentsatz der Explantate, die überhaupt Adventivknospen ausbildeten.

Determination of mean atmospheric densities from the explorer ix satellite

Mean atmospheric densities from changes in orbital elements of Explorer IX satellit

Profile scaling in decay of nanostructures

The flattening of a crystal cone below its roughening transition is studied by means of a step flow model. Numerical and analytical analyses show that the height profile, h(r,t), obeys the scaling scenario dh/dr = F(r t^{-1/4}). The scaling function is flat at radii r<R(t) \sim t^{1/4}. We find a one parameter family of solutions for the scaling function, and propose a selection criterion for the unique solution the system reaches.Comment: 4 pages, RevTex, 3 eps figure

HIV-1 superinfection with a triple-class drug-resistant strain in a patient successfully controlled with antiretroviral treatment.

We report a case of HIV-1 superinfection (HSI) with a clade B, triple-class resistant virus in a patient successfully controlling viremia with continuous combination antiretroviral therapy started 8 years earlier during primary HIV infection. The course of HIV infection prior to HSI was monitored in both the source partner and recipient (8 and 11 years, respectively) and 4 years following HSI. This case report demonstrates re-infection with HIV-1 despite effective combination antiretroviral therapy

Dewetting of an ultrathin solid film on a lattice-matched or amorphous substrate

An evolution partial differential equation for the surface of a non-wetting single-crystal film in an attractive substrate potential is derived and used to study the dynamics of a pinhole for the varying initial depth of a pinhole and the strengths of the potential and the surface energy anisotropy. The results of the simulations demonstrate how the corresponding parameters may lead to complete or partial dewetting of the film. Anisotropy of the surface energy, through faceting of the pinhole walls, is found to most drastically affect the time to film rupture. In particular, the similations support the conjecture that the strong anisotropy is capable of the complete suppression of dewetting even when the attractive substrate potential is strong.Comment: Submitted to PR