Induction of callus formation from difficile date palm protoplasts by means of nurse culture.

We report here for the first time callus formation from protoplasts in date palm (Phoenix dactylifera L.). Protoplasts were isolated from young leaves of offshoots and embryogenic calli in Deglet nour and Takerboucht genotypes.

Production of potato intraspecific somatic hybrids with improved tolerance to PVY and Pythium aphanidermatum.

Somatic hybridization can be an interesting alternative for the selection of heterozygous and vigorous potato plants through combination of dihaploid genomes. The resulting hybrids can harbour interesting characters and thus can be used in agriculture if they are in agreement with agronomic criteria. In this report, we used an intraspecific somatic hybridization technique for the production of tetraploid potato lines.

Source of resistance against Ralstonia solanacearum in fertile somatic hybrids of eggplant (Solanum melongena L.) with Solanum aethiopicum L.

Solanum aethiopicum is reported to carry resistance to bacterial wilt disease caused by Ralstonia solanacearum, which is one of the most important diseases of eggplant (Solanum melongena). These two species can sexually be crossed but the fertility of their progeny is very low. In order to transfer the resistance and improve the fertility, somatic hybrids between S.

Resistance to bacterial wilt in somatic hybrids between Solanum tuberosum and Solanum phureja.

Somatic hybrid plants were produced after protoplast electrofusion between a dihaploid potato, cv. BF15, and a wild tuber-bearing relative, Solanum phureja, with a view to transferring bacterial wilt resistance into potato lines. A total of ten putative hybrids were selected.

[Cortex-wall connections in the apical cell of Sphacelaria].

The apical cell of Sphacelaria (Fucophyceae) exhibits a permanent polarized organization throughout asymmetric divisions. The apex organization was studied by immunolocalization of tubulin, vitronectin, alpha-actinin and beta 1 integrin. Microfilaments were stained directly by fluorescein phalloidin.

Somatic and zygotic embryos of Daucus carota L. display different protein patterns until conversion to plants.

Total protein patterns of different developmental stages of carrot zygotic and somatic embryos revealed by one- and two-dimensional gel electrophoresis were compared using statistical dissimilarity index matrix, and some major polypeptides were partially sequenced. In spite of similar morphology, the protein patterns of somatic embryos at the torpedo stage were clearly different from those of zygotic embryos. In particular, none of the proteins specific of zygotic embryos required for maturation, previously identified, were accumulated in somatic embryos, namely the daucin (a globulin-type storage protein), the RAB25 protein (a late embryogenesis abundant protein) (Dodeman et al.

Characterization of storage proteins in Daucus carota L.: two novel proteins display zygotic embryo specificity.

Although maturation-related proteins are well known in the endosperm of albuminous seeds, an important question is whether the zygotic embryo possesses its own maturation proteins. We report on the isolation and partial characterization of storage proteins of carrot (Daucus carota L. var Nandor) dry achenes and isolated zygotic embryos, using one- and two-dimensional electrophoresis techniques, HPLC and amino acid sequencing.

Immunological detection of potential signal-transduction proteins expressed during wheat somatic tissue culture.

An immunochemical approach was used to detect the expression of putative guanine nucleotide-binding proteins (G-proteins), arrestin, and nucleoside diphosphate kinases during wheat (Triticum aestivum) tissue culture initiated from immature embryos. Both the soluble and membrane extracts from the immature embryos revealed bands of 58, 40, and 16 kD with antibodies to G-protein (alpha subunit), arrestin, and nucleoside diphosphate kinase, respectively. These proteins were overexpressed in vitro in both nonembryogenic callus and embryogenic cultures.

Isozyme patterns in zygotic and somatic embryogenesis of carrot.

Isozyme patterns of carrot (Daucus carota L.) zygotic embryos between the torpedo stage up to 5-day-old seedlings have been compared with those of the similar stages from the embryogenic cell suspension culture to the late somatic plantlet. Somatic embryos blocked at the torpedo stage by β-cyclodextrine have also been analyzed.

Isozyme modifications and plant regeneration through somatic embryogenesis in sweet potato (Ipomoea batatas (L.) Lam.).

The potential of somatic embryogenesis was evaluated for 10 cultivars of sweet potato through extensive embryogenic response and isozyme analysis. Embryogenic callus was induced by incubating lateral buds on Murashige and Skoog medium containing 10 μM 2,4-dichlorophenoxyacetic acid for 6-8 weeks. The frequency of embryogenic response was low, and varied with genotypes, ranging from 0 to 17%.

Production and characterization of fertile somatic hybrids of eggplant (Solanum melongena L.) with Solanum aethiopicum L.

In order to produce fertile somatic hybrids, mesophyll protoplasts from eggplant were electrofused with those from one of its close related species, Solanum aethiopicum L. Aculeatum group. On the basis of differences in the cultural behavior of the parental and hybrid protoplasts, 35 somatic hybrid plants were recovered from 85 selected calli.

Somatic hybrid plants produced by electrofusion between dihaploid potatoes: BF15 (H1), Aminca (H6) and Cardinal (H3).

In order to regenerate somatic hybrids, mesophyll protoplasts from a dihaploid potato, BF15 (H1), were electrofused with those from two other dihaploid clones, Aminca (H6) and Cardinal (H3). Determination of the ploidy level by flow cytometry showed that 10% of plants regenerated from the fusion experiment with "BF15 + Aminca" were diploids, 14% triploids, 63% tetraploids and very few were mixoploids or had a higher ploidy level. Using morphological markers and vigour in plant growth, we were able to recover a total of 24 somatic hybrid plants, respectively 20 and 4 hybrids (accounting for 12% and 13% of regenerants) from the fusions "BF15 + Aminca" and "BF15 + Cardinal".

Somatic hybrid plants produced by electrofusion between Solanum melongena L. and Solanum torvum Sw.

Somatic hybrid plants between eggplant (Solanum melongena) and Solanum torvum have been produced by the electrofusion of mesophyll protoplasts in a movable multi-electrode fusion chamber. Using hair structure as a selection criteria, we identified a total of 19 somatic hybrids, which represented an overall average of 15.3% of the 124 regenerated plants obtained in the two fusion experiments.

Plant regeneration from protoplasts of Sphacelaria (Phaeophyceae).

Protoplast were isolated from a filamentous brown alga, Sphacelaria sp. (Sphacelariales, Phaeophyta), using alginate-lyases extracted from marine molluscs, and commercial pectinase and cellulase. Yields were about 4000 protoplasts per gram of fresh tissue.

Plant regeneration from protoplast culture of sweet potato (Ipomoea batatas Lam.).

This is the first report on successful plant regeneration from protoplasts of sweet potato. Two cultivars (Guyana and Duclos XI) of sweet potato plants propagated under in vitro conditions were used as the source of protoplasts. Green compact calli with meristematic areas were induced in the medium supplemented with 2mg1(-1) zeatin, and plant regeneration occurred when these calli were transferred onto the medium with zeatin level reduced to 0.