ISHS Acta Horticulturae 651: XXI International Eucarpia Symposium on Classical versus Molecular Breeding of Ornamentals - Part II
GENE AND GENOME MÉLANGE IN BREEDING OF ANTHURIUM AND DENDROBIUM ORCHID |
| Authors: | A.R. Kuehnle, T. Fujii, R. Mudalige, A. Alvarez |
| Keywords: | Lytic peptide, blight resistance, dihydroflavanol 4-reductase |
| Abstract:
Both genome breeding (classical hybridisation) and molecular breeding approaches are used concurrently in our program for varietal development of Dendrobium and Anthurium as cut flowers and blooming potted plants. Two transgenic lines of anthurium 'Paradise Pink', engineered to produce the cecropin-like Shiva 1 lytic peptide, were able to significantly resist anthurium blight caused by Xanthomonas campestris pv. dieffenbachiae when compared to a standard resistant cultivar 'Kalapana'. However, disease severity could be significantly increased as well using the same transgene approach in a different genotype, 'Tropic Flame'. These lines were shown to be compatible with beneficial leaf-associated bacteria that can aid in suppressing blight, suggesting that use of GMO plants could be combined with beneficial bacteria to provide durable protection against anthurium blight disease. Blight resistance incorporated by hybridisation of A. andraeanum types with A. antioquiense also enhanced resistance, but the market-desired heart-shaped spathe form was difficult to recover. Both gene and genome breeding for resistance occurred in a comparable time frame of less than 10 years. Dendrobium orchid breeding has benefit greatly from molecular tools in understanding genetic control of flower colour. A chemical survey of Dendrobium species and hybrids showed lavender cyanidin and peonidin to be the predominant anthocyanidin and orange pelargonidin to be rare. Our cloning and characterization of key anthocyanin biosynthetic genes such as of dihydroflavanol 4-reductase enables more productive hybridisation strategies to be implemented. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
