Growth at high CO2 affects the chloroplast number but not the photosynthetic efficiency of photoautotrophicMarchantia polymorpha culture cells

Shoot tips from accessions of wild cherry (Prunus avium L.) selected from British woodland, and also theP. avium rootstock cvs. F12/1 and Charger, were successfully establishedin vitro, and most were easily micropropagated on Murashige and Skoog (MS)-based media. In one accession, adventitious shoots occasionally developed from the extrafloral nectaries positioned at the base of leaf petioles of the initial explants. Micropropagation of cv. Charger was improved by culture on a Quoirin and Lepoivre and Woody Plant-based medium, and by supplementing the medium with 1-phenyl-3-(1, 2, 3-thiadiazol-5yl)urea (thidiazuron). Poor shoot production by F12/1 on 1, 3, 5-trihydroxybenzene (phloroglucinol)-free media was not improved by up to 18 months of regular subculture. Study of cv. F12/1 showed that shoots produced on a MS-based medium with 1 mM phloroglucinol, 0.49 μM indolebutyric acid, 4.4 μM benzyladenine (BA) and 0.29 μM gibberellic acid (GA₃), were easier to root over several subcultures than shoots produced on a similar medium with no GA₃ and only 2.2 μM BA, but only in a rooting medium supplemented with 1 mM phloroglucinol.