title: Effects of fusaric acid treatment on the protocorm-like bodies of Dendrobium sonia-28.
abstract: Dendrobium sonia-28 is a popular orchid hybrid due to its flowering recurrence and dense inflorescences. Unfortunately, it is being decimated by fungal diseases, especially those caused by Fusarium proliferatum. In this study, selection of F. proliferatum-tolerant protocorm-like bodies (PLBs) was carried out by assessing the effects of differing concentrations of fusaric acid (FA). PLBs were cultured on Murashige and Skoog (MS) medium supplemented with 0.05 to 0.2 millimolar (mM) concentrations of FA. Higher concentrations of FA increased mortality of PLBs and reduced their growth. The survival rate for 0.05 mM FA was 20 % but only 1 % at the highest dose of 0.2 mM. Additionally, two different size ranges of PLBs were investigated, and growth increased more at lower FA concentrations for larger PLBs, whilst the growth rate of smaller PLBs was inhibited at an FA concentration of 0.2 mM. Histological examination using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses disclosed severe cell wall and organelle damage, as well as stomatal closure in PLBs treated with the high FA concentrations. Reductions in plantlet growth were much greater at the highest concentrations of FA. Some randomly amplified polymorphic DNA (RAPD) markers clearly discriminated between selected and non-selected variants of Dendrobium sonia-28, showing different banding patterns for each FA concentration and specific bands for selected and control plants.
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Georgetown, Penang, Malaysia.
authors.forename: Raheleh
authors.initials: R
authors.lastname: Dehgahi
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Georgetown, Penang, Malaysia.
authors.forename: Latiffah
authors.initials: L
authors.lastname: Zakaria
authors.affiliation: Agrotechnology and Bioscience Division, Malaysian Nuclear Agency, 43000, Bangi, Kajang, Malaysia.
authors.forename: Azhar
authors.initials: A
authors.lastname: Mohamad
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Georgetown, Penang, Malaysia.
authors.forename: Alireza
authors.initials: A
authors.lastname: Joniyas
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Georgetown, Penang, Malaysia. sreeramanan@gmail.com.
authors.forename: Sreeramanan
authors.initials: S
authors.lastname: Subramaniam
mesh_terms: D002473:Cell Wall / Q000473:pathology; D031667:Dendrobium / Q000196:embryology* / Q000382:microbiology / Q000648:ultrastructure*; D005669:Fusaric Acid / Q000494:pharmacology*; D005670:Fusarium / Q000472:pathogenicity; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010935:Plant Diseases / Q000382:microbiology; D018520:Plant Shoots / Q000254:growth & development* / Q000648:ultrastructure*; D019105:Random Amplified Polymorphic DNA Technique
chemical_list: D005669:Fusaric Acid
keywords: Dendrobium sonia-28; Fusaric acid; PLBs; Somaclonal variation