Protoplast

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

Intergeneric somatic hybrids of rice [Oryza sativa L. (+) Porteresia coarctata (Roxb.) Tateoka]

Abstract: Somatic hybrid plants were obtained following the electrofusion of rice (Oryza sativa L. cv ’Taipei 309’, 2n = 2x = 24) cell suspension–derived protoplasts with non-dividing leaf protoplasts of Porteresia coarctata (2n = 4x = 48), a saline-tolerant wild species. Fusion-treated protoplasts were plated on the surface of cellulose nitrate filter membranes, overlaying Lolium multiflorum nurse cells. The nurse cells were embedded in KPR medium containing 0.5 mg l−1 2,4–dichlorophenoxyacetic acid and semi-solidified with SeaPlaque agarose. Putative somatic hybrid cell colonies were selected on the basis of their growth, whereby faster growing colonies were transferred preferentially to MS-based medium with 2.0 mg l−1 kinetin, 0.5 mg l−1α-naphthaleneacetic acid, 30 g l−1 sucrose and 4.0 g l−1 SeaKem agarose to induce shoot regeneration. One hundred and nineteen regenerated plants were micropropagated clonally on MS-based medium containing 2.0 mg l−1 6–benzylaminopurine, 50 g l−1 sucrose and 4.0 g l−1 SeaKem agarose, prior to DNA extraction of plant samples. Putative somatic hybrids were initially identified by RAPD analysis, and 8 plant lines were selected for further investigation by flow cytometric ploidy determination and cytology. Plants of one line had an allohexaploid chromosome complement (2n = 6x = 72) and, following examination of its vegetative clones by GISH, were confirmed as somatic hybrids containing full chromosome complements of both O. sativa and P. coarctata.

Production and characterization of somatic hybrid plants between leek (Allium ampeloprasum L.) and onion (Allium cepa L.)

Abstract: Results are reported on the production and characterization of somatic hybrids between Allium ampeloprasum and A. cepa. Both symmetric and asymmetric protoplast fusions were carried out using a polyethylene-based mass fusion protocol. Asymmetric fusions were performed using gamma ray-treated donor protoplasts of A. cepa and iodoacetamide-treated A. ampeloprasum protoplasts. However, the use of gamma irradiation to eliminate or inactivate the donor DNA of A. cepa proved to be detrimental to the development of fusion calli, and thus it was not possible to obtain hybrids from asymmetric fusions. The symmetric fusions yielded a high number of hybrid calli and regenerated plants. The analysis of the nuclear DNA composition using interspecific variation of rDNA revealed that most of the regenerated plants were hybrids. Flow cytometric analysis of nuclear DNA showed that these hybrid plants contained a lower DNA content than the sum of the DNA amounts of the parental species, suggesting that they were aneuploid. A shortage of chromosomes in the hybrids was confirmed by genomic in situ hybridization. Chromosome counts in metaphase cells of six hybrids revealed that these plants lacked 2–7 leek chromosomes. One hybrid showed also the loss of onion chromosomes. The hybrids had an intermediate phenotype in leaf morphology. The application of these somatic hybrids in breeding is discussed.

Protoplast Cultures from Cell Suspensions of Daucus carota

Abstract: Protoplasts, enzymatically isolated from cell suspension cultures of Daucus carota, have been grown in small Petri-dishes. After enzyme treatment and washing the protoplasts were plated in agar media. Growth and divisions were viewed through the bottom of the Petri-dishes with a light microscope. Different osmotic stabilizers were tested with respect to their ability to promote wall formation and growth of the protoplasts. Combinations of sucrose, sorbitol and “Modopeg” gave the best results. Electron micrographs of cultured protoplasts revealed normal as well as abnormal nuclear conditions.