TY - JOUR
T1 - Reproductive Potential of Obligate Seeder and Resprouter Herbaceous Perennial Monocots (Restionaceae, Anarthriaceae, Ecdeiocoleaceae) from South-western Western Australia
AU - Meney, K.A.
AU - Dixon, K.W.
AU - Pate, John
PY - 1997
Y1 - 1997
N2 - Pre- and post-dispersal reproductive success was studied in 22 species from three related Southern Hemisphere families, Restionaceae, Ecdeiocoleaceae and Anarthriaceae. Pre-dispersal success was compared for resprouter and obligate seeder species using seed:ovule ratios and carpel:flower ratios. The data indicated a high level of variability between taxa but pre-dispersal reproductive success of obligate seeders was significantly higher (67% conversion of ovules to seeds) than that of resprouters (35%). Two seeders, an extremely rare species ('Chordifex' abortivus) and a strongly clonal species (Alexgeorgea subterranea), showed pre-dispersal reproductive success values lower than or equal to the mean value for resprouters. Post-dispersal reproductive success was predicted in terms of proportions of germinable seeds produced per ovule (as determined by in vitro germination of isolated embryos). Data again varied widely between taxa, averaging 23% conversion of ovules to seeds with no clear relationship to regeneration mode. The mean number of germinable seeds per culm ranged from 0.03 to 21 between species, with cases of particularly low ovule output and/or low germinability in critically low germinable seed numbers for a species. The regeneration potential of a subset of species was assessed as mean annual production of germinable seed per reproducing plant of a population. The data indicated low values (less than eight seeds per adult) for all but three highly fecund species, suggesting that germinable seed output in some species might be scarcely able to compensate for natural senescence or catastrophic loss of parent populations (e.g. after fire, disease, increased competition following eutrophication).
AB - Pre- and post-dispersal reproductive success was studied in 22 species from three related Southern Hemisphere families, Restionaceae, Ecdeiocoleaceae and Anarthriaceae. Pre-dispersal success was compared for resprouter and obligate seeder species using seed:ovule ratios and carpel:flower ratios. The data indicated a high level of variability between taxa but pre-dispersal reproductive success of obligate seeders was significantly higher (67% conversion of ovules to seeds) than that of resprouters (35%). Two seeders, an extremely rare species ('Chordifex' abortivus) and a strongly clonal species (Alexgeorgea subterranea), showed pre-dispersal reproductive success values lower than or equal to the mean value for resprouters. Post-dispersal reproductive success was predicted in terms of proportions of germinable seeds produced per ovule (as determined by in vitro germination of isolated embryos). Data again varied widely between taxa, averaging 23% conversion of ovules to seeds with no clear relationship to regeneration mode. The mean number of germinable seeds per culm ranged from 0.03 to 21 between species, with cases of particularly low ovule output and/or low germinability in critically low germinable seed numbers for a species. The regeneration potential of a subset of species was assessed as mean annual production of germinable seed per reproducing plant of a population. The data indicated low values (less than eight seeds per adult) for all but three highly fecund species, suggesting that germinable seed output in some species might be scarcely able to compensate for natural senescence or catastrophic loss of parent populations (e.g. after fire, disease, increased competition following eutrophication).
U2 - 10.1071/BT96028
DO - 10.1071/BT96028
M3 - Article
VL - 45
SP - 771
EP - 782
JO - Australian Journal of Botany
JF - Australian Journal of Botany
ER -