H. incana is a native species of the Mediterranean and Middle East. As a neophyte (alien) it has undergone a large range expansion in Northern Europe, the Americas, Asia and Australasia. Casual field observations suggested that within its native range, the dominant life strategy of H.incana was annual, whereas in the British flora it was predominantly perennial. Populations from native and alien ranges were studied in the field and in common garden experiments. Phenotypic differences in morphological and physiological characteristics were compared. Plants derived from neophyte British populations made larger leaf rosettes, flowered later (> 140 days) and exhibited a perennial life cycle. Plants from native. North African and Southern European populations (excepting those from montane Spain) made smaller rosettes, flowered early (< 110 days) and died after flowering once. Neophyte populations from California were similar to native populations. Some native populations (e.g. Cypress) did not survive a British winter. Unlike native populations, initiation of flowering in neophyte British populations was stimulated by a period of vernalisation. These results suggest that life strategy changes have occurred in neophyte populations of H. incana as this species expanded its range northwards, and implies possible genetic differences. Ten microsatellite primers, previously described for related Brassicaceae species, were therefore investigated for potential use in the assessment of H. incana population genetic structure. Five primers successfully amplified a product of expected size, of which 3 were subscequently sequenced to confirm the presence of the SSR. The application of real-time PCR DNA melting analysis to identify SSR variation was investigated using Roche SYBR green and Corbett HRM platforms. SSR variation could be detected using DNA melt analysis, but due to difficulty identifying the composition of heterozygous SSR's the technique could not be sufficiently refined to investigate population diversity. However, preliminary results indicated possible SSR variation between isolated populations.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:678681 |
| Date | January 2010 |
| Creators | Smith, Melvin N. E. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://cronfa.swan.ac.uk/Record/cronfa42609 |
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