Schöpke C. auteur aut IRD Taylor N.J. auteur aut IRD Carcamo R. auteur aut IRD Beachy R.N. auteur aut IRD Fauquet Claude auteur aut IRD text journalArticle eng text/pdf reformatted digital access Tissue derived from embryonic suspension cultures of cassava was bombarded with microparticles coated with a plasmid containing the uidA gene, which codes for beta-glucuronidase (GUS). After 3 days, the effect of different bombardment parameters was evaluated by comparing the numbers of blue spots that resulted from histological GUS assays. Counting of blue spots was performed using a system comprised of a black and white video camera, a stereoscope and a personal computer. A reproducible counting method was established by optimizing GUS assay conditions, preparation of tissue samples and acquisition of video images in view of attaining the highest possible contrast between the blue spots and the surrounding tissue. The effects of bombardment pressure, microparticle size, number of bombardments, and osmotic pretreatment on GUS expression were investigated. Optimal transient expression of the uidA gene was observed after bombardment at 1100 psi, with a particle size of 1 micrometer, an osmotic pretreatment and two bombardments per sample. The highest number of blue spots observed was 2400 per square centimeter of bombarded tissue. (Résumé d'auteur) specialized AMELIORATION DES PLANTES AMELIORATION GENETIQUE EMBRYON ZYGOTIQUE CULTURE IN VITRO ANALYSE D'IMAGE BIOLISTIQUE 076AMEPLA04 084VITRO 16 8 526-530 1997 0721-7714 https://www.documentation.ird.fr/hor/fdi:010010396 10.1007/BF01142317 0721-7714 [F B010010396] https://www.documentation.ird.fr/hor/fdi:010010396 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_47-48/010010396.pdf IRD - Base Horizon / Pleins textes 1997-06-12 2017-08-07 fdi:010010396 fre