Núñez de Cáceres González, Francisco Federico
Genetic manipulation of agronomically important traits in Lilium.
PhD thesis, University of Nottingham.
The ornamental industry has become an important economic force in recent years, in the UK alone this industry is estimated to be around £2.1 billion, while the international trade is around £60-75 billion (Chandler and Tanaka, 2007). The continued success of the floriculture industry depends on the introduction of new species/cultivars with major alterations in key agronomic characteristics, such as resistance to pathogens, novel flower colour and patterns or control of male fertility. Lilium, one of the most important bulbous ornamental crops, is an attractive and popular cut flower. However, the production of vast quantities of pollen that stains easily and is toxic to animals is not always desirable. The control of pollen release without affecting the appearance of the flower is therefore an important breeding goal. Lilium is also susceptible to several fungal pathogens, including Botrytis cinerea, which infects leaves, stem and flowers leading to a reduction of yield. New cultivars have tended to rely upon selective breeding as a mechanism for trait development. However approaches that utilise transgenes to manipulate traits of interest provide alternative opportunities for the ornamental industry provided that transformation and regeneration can be achieved efficiently.
A rapid, highly efficient and reproducible Agrobacterium-mediated transformation for Lilium has been developed. Successful transient GUS expression in callus, shoots and basal plate discs was achieved using A. tumefaciens strain AGL1 containing plasmid pBI121 harbouring intron-containing GUS and NPTII genes in cultivars "Beverly's Dream", "Star Gazer", "Night Flyer", "Acapulco", "Sweet Surrender" and Lilium leichtlinii.
Based on the same transformation protocol, transgenic plants of cv. "Star Gazer" overexpressing the RCH10 chitinase gene from rice were generated. In vitro sporulation assays of these plants showed different levels of resistance to Botrytis cinerea correlated to the level of relative expression of the transgene. This is the first report of induced pathogen resistance in any Lilium cultivar by transgenic approach.
Experiments were also conducted to modify fertility and pollen release in Lilium by translating regulatory gene information from Arabidopsis to Lilium. Transgenic plants of cv. "Star Gazer" either overexpressing or silencing the AtMYB26 gene, were generated. RNAi lines showed a delay in anther dehiscence suggesting that pollen development pathways could be conserved between Arabidopsis and Lilium. In addition, partial sequences of the putative orthologues of AtMS1 and AtMYB26 in Lilium were identified and cloned for future research.
Thesis (University of Nottingham only)
||Q Science > QK Botany > QK457 Spermatophyta. Phanerogams
Q Science > QK Botany > QK640 Plant anatomy
||UK Campuses > Faculty of Science > School of Biosciences
||19 Sep 2014 10:06
||15 Sep 2016 09:37
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