Vaughton, GV; Ramsey, MW

Author(s)

Vaughton, GV

Ramsey, MW

Publication Date

2004

Abstract

In flowering plants, the evolution of dimorphic breeding systems from monomorphic ancestors can be associated with dry environments. One hypothesis to explain this pattern is that seed fertility of hermaphrodites decreases more than seed fertility of females under dry conditions, so that females have greater relative fitness. This could occur if seed production of hermaphrodites is more resource-limited than that of females, or shifts in pollination increase levels of selfing and inbreeding depression in hermaphrodites.Here we assess the role of dry environments in promoting a female fitness advantage in Wurmbea biglandulosa by focusing on monomorphic and dimorphic populations that occur along a longitudinal gradient of decreasing rainfall. Dimorphic populations occurred in sites with higher temperatures, lower rainfall and lower soil moisture. Overall, females had greater seed fertility than did hermaphrodites from monomorphic populations, which in turn had greater seed fertility than hermaphrodites from dimorphic populations. Ovuliferous flower and ovule production by the three gender morphs and seed fertility of females and hermaphrodites in monomorphic populations did not vary with soil moisture. By contrast, seed fertility of hermaphroditesin dimorphic populations was positively related to soil moisture. Accordingly, female frequency was higher in those sites where hermaphrodites produced relatively fewer seeds. Taken together our results indicate that dry environments promote the establishment of females by decreasing the relative seed fitness of hermaphrodites. Moreover, because seed fertility of hermaphrodites in monomorphic populations did not vary with soil moisture, resource limitation offemale function may play only a minor role in the establishment of females. Other factors such as shifts in pollination and mating patterns of hermaphrodites could be involved.

Citation

Evolutionary Ecology, 18(4), p. 323-341

ISSN

1573-8477

0269-7653

Link

https://hdl.handle.net/1959.11/133

Publisher

Kluwer Academic Publishers

Title

Dry environments promote the establishment of females in monomorphic populations in Wurmbea biglandulosa (Colchicaceae)

Type of document

Journal Article

Entity Type

Publication

Author(s)	Vaughton, GV Ramsey, MW
Publication Date	2004
Abstract	In flowering plants, the evolution of dimorphic breeding systems from monomorphic ancestors can be associated with dry environments. One hypothesis to explain this pattern is that seed fertility of hermaphrodites decreases more than seed fertility of females under dry conditions, so that females have greater relative fitness. This could occur if seed production of hermaphrodites is more resource-limited than that of females, or shifts in pollination increase levels of selfing and inbreeding depression in hermaphrodites.Here we assess the role of dry environments in promoting a female fitness advantage in Wurmbea biglandulosa by focusing on monomorphic and dimorphic populations that occur along a longitudinal gradient of decreasing rainfall. Dimorphic populations occurred in sites with higher temperatures, lower rainfall and lower soil moisture. Overall, females had greater seed fertility than did hermaphrodites from monomorphic populations, which in turn had greater seed fertility than hermaphrodites from dimorphic populations. Ovuliferous flower and ovule production by the three gender morphs and seed fertility of females and hermaphrodites in monomorphic populations did not vary with soil moisture. By contrast, seed fertility of hermaphroditesin dimorphic populations was positively related to soil moisture. Accordingly, female frequency was higher in those sites where hermaphrodites produced relatively fewer seeds. Taken together our results indicate that dry environments promote the establishment of females by decreasing the relative seed fitness of hermaphrodites. Moreover, because seed fertility of hermaphrodites in monomorphic populations did not vary with soil moisture, resource limitation offemale function may play only a minor role in the establishment of females. Other factors such as shifts in pollination and mating patterns of hermaphrodites could be involved.
Citation	Evolutionary Ecology, 18(4), p. 323-341
ISSN	1573-8477 0269-7653
Link	https://hdl.handle.net/1959.11/133
Publisher	Kluwer Academic Publishers
Title	Dry environments promote the establishment of females in monomorphic populations in Wurmbea biglandulosa (Colchicaceae)
Type of document	Journal Article
Entity Type	Publication

Dry environments promote the establishment of females in monomorphic populations in Wurmbea biglandulosa (Colchicaceae)

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