Protoplast

About: Protoplast is a research topic. Over the lifetime, 5474 publications have been published within this topic receiving 122468 citations.

Investigation of the response to salinity and to oxidative stress of interspecific potato somatic hybrids grown in a greenhouse

Abstract: Salinity is one of the major stresses threatening potato plants (Solanum tuberosum L.) by affecting their growth and yield. It leads to oxidative stress by the production of reactive oxygen species responsible for alteration of macromolecules. To improve the tolerance of potato to salt stress, we have used somatic hybridization to produce interspecific potato hybrids by protoplast fusion between the BF15 variety and the wild Solanum berthaultii species. These hybrids showed an improved tolerance to salt stress when cultivated in vitro. The present work aims to analyze the response of the hybrids to salt stress in greenhouse conditions. Thus, the development of plants and their antioxidant capacity in response to salt stress were followed. All hybrids showed better growth and stable chlorophyll content compared to those of the BF15 parent plant. Membrane lipid peroxidation, evaluated by measuring the malondialdehyde accumulation (MDA) in plant organs, showed low levels in the hybrids. Higher antioxidant enzyme activities were measured in the roots of the hybrids when compared to those of the BF15 parent. These hybrids also showed an improved control of Na+ accumulation and a stable K+/Na+ ratio. These results therefore confirm the better tolerance of these hybrids to salt stress when compared to their BF15 parent.

Improved culture ability of potato protoplasts by use of activated charcoal.

Abstract: Protoplasts were obtained from in vitro grown plants of Solanum tuberosum L. The protoplasts were cultured in X-plate petri dishes with the culture medium joined to a reservoirmedium. When activated charcoal was added to the reservoirmedium the culture ability of the protoplasts was significantly increased. The effect of activated charcoal was mainly due to a less pronounced browning of the developing protoplasts and this technique might be of help in protoplast cultures where browning is a problem.

Analysis of plants regenerated from protoplast fusions between Brassica napus and Eruca sativa.

Abstract: Protoplasts from etiolated hypocotyls of Brassica napus stained with carboxyfluorescein were fused with mesophyll protoplasts from Eruca sativa. Hybrid cells could be identified under the light microscope by (1) fully developed chloroplasts derived from E. sativa and (2) the cytoplasmic strands of the B. napus hypocotyl protoplasts, or (3) by the presence of both red and green fluorescence when investigated under UV light. The heterokaryons were selected using either a micro-manipulator or a flow sorter. On average, 5.4% of the calli obtained after selection differentiated into shoots. Regenerated shoots were subjected to isozyme analysis for verification of their hybrid character. Of the 23 hybrids successfully transferred to the greenhouse, 11 were asymmetric according to isozyme analysis. The nuclear DNA content of the hybrids was determined by flow cytometry, which gives an estimate of chromosome number. Most of the hybrids had a DNA content, and thus a chromosome number, that deviated from the expected sum of the parents. Almost all of the hybrids had some degree of fertility and produced seeds. Seed set, expressed as seeds per pollinated flower, was on average 7% of that of B. napus in the case of self-pollination and 26% of that of B. napus when backcrossed to B. napus. The chloroplast genotype was investigated in 13 hybrids. Of these, 11 had chloroplasts derived from B. napus, while only 2 had chloroplasts of E. sativa origin.

Callus formation from mesophyll protoplasts of Pisum sativum

Abstract: Protoplasts isolated from mesophyll of Pisum sativum L. cv. Century, and cultured in 0.2-ml droplets of B5 medium with 1.0 mg/liter (2,4-dichlorophenoxy)acetic acid (2,4-D) or 1-naphthaleneacetic acid (NAA) and 2.0 mg/liter kinetin regenerated cell walls within 2–3 days. The resulting cells began to divide and form calli after 19 days of culture. Protoplast survival depended on keeping the leaf material in the dark for at least 30 h before use.

Improved isolation of dihaploid Solanum tubersoum protoplasts and the production of somatic hybrids between dihaploid S. tuberosum and S. brevidens

Abstract: A modified protoplast isolation technique, applicable to a range of dihaploidSolanum tuberosum genotypes, has been developed. A combination of high calcium and high pH was used to fuse mesophyl protoplasts of dihaploidS. tuberosum (PDH40) and the diploid wild speciesS. brevidens. Large numbers of colonies were obtained after fusion and putative hybrids selected on the basis of phenotype from regenerated shoots. From these, 11 somatic hybrid plants have been identified by their isoenzyme patterns and morphologic characteristics. Four of these hybrids had the expected chromosome number of 48. The approach of mass culture after fusion followed by selection of hybrids from regenerated shoots and the application of somatic hybridization to potato breeding are discussed.