Tag Archives: Cryopreservation

In vitro Conservation of Guava (Psidium guajava L.) var. Al-Baladi

Rehab Al Mousa*(1) Neveen Hassan(2) Ramzy Stino(3) and Amina Gomaa(3)

(1). Department of Biotechnology, General Commission for Scientific Agricultural Research, Damascus, Syria.

(2). National Gene Bank and Genetic Resources, Agricultural Research Center, Giza, Egypt.

(3). Pomology Department, Faculty of agriculture, Cairo University, Giza, Egypt.

(*Corresponding author: Dr. Rehab Al Mousa. E-Mail: bebo_moussa13@yahoo.com).

Received: 04/01/2018                                Accepted: 06/02/2018

Abstract

This study was conducted at the National Gene Bank, Egypt, from 2012 to 2014; to find out in vitro conservation protocol of guava (Psidium guajava L. var. Al-Baladi). The medium-term conservation study was initiated at 10 and 15°C under complete darkness conditions. Shoot tip explants were cultured on MS medium with different concentrations (3.0, 4.0, 5.0 and 6.0%) of sucrose or sorbitol. After 6 months of conservation, up to 83.33% of explants survived on medium with 5.0% sorbitol at 15ºC, while the same survival% (66.67%) was noticed when explants conserved on medium with 6.0% of sorbitol at 15ºC and on medium with 5.0 or 6.0% of sorbitol at 10ºC. Regeneration%, shoot number of explant and shoot length were not affected by osmotic concentrations. Meanwhile, all explants lost their ability to regenerate new shoots when conserved for 6 months on medium with 3.0% sucrose (control) at 10ºC. Guava seeds recorded 100% germination when desiccated for 6 h before cryopreservation in liquid nitrogen.

Keywords: Guava, Medium-term conservation, Sucrose, Sorbitol, Cryopreservation, Desiccation.

Full Paper in Arabic: PDF

Methods for Maintaining Insect Cells Sf9 and its Morphological Characterization

Manal Saleh*(1)

(1). General Organization of Biotechnology, Damascus, Syria.

(*Corresponding author: Eng. Manal Saleh. E-Mail: manalcapno@gmail.com).

Received: 04/10/2016                                 Accepted: 18/11/2016

Abstract

The insect cell lines have a great importance in scientific research such as: Physiological and biological studies, producing biopesticides and vaccines, biotechnology and toxicology. The insect cell line Sf9, is derived from an immature pupal ovarian tissue of Spodoptera frugiperda. These cells were cultured, sub-cultured (more than 23 subculture) and cryopreserved. Morphological characterization of Sf9 cells were performed by using three staining methods i.e. Trypan blue, Wright, and Giemsa. Three different shapes of Sf9 cells were observed and they were: Spherical cells (large and small ones); fibroblast-like cells, and phagocytic cells. Two different populations of cells were identified in Sf9 cell cultures according to nuclear number: Mononucleated and polynucleated to ensure cells surviving.

Key word: Sf9 insect cell lines, Spodoptera frugiperda, Subculture, Cryopreservation, Morphological characterization.

Full paper in Arabic: PDF