Pistillate flowers experience more pollen limitation and less geitonogamy than perfect flowers in a gynomonoecious herb
Article first published online: 23 SEP 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 201, Issue 2, pages 670–677, January 2014
How to Cite
Mamut, J., Xiong, Y.-Z., Tan, D.-Y. and Huang, S.-Q. (2014), Pistillate flowers experience more pollen limitation and less geitonogamy than perfect flowers in a gynomonoecious herb. New Phytologist, 201: 670–677. doi: 10.1111/nph.12525
- Issue published online: 18 DEC 2013
- Article first published online: 23 SEP 2013
- Manuscript Accepted: 22 AUG 2013
- Manuscript Received: 23 JUN 2013
- National Science Foundation of China. Grant Numbers: U1130301, 31030016
- Xinjiang Agricultural University. Grant Number: XJCYB-2011-06
- Key Program for International S & T Cooperation Projects of China. Grant Number: 2011DFA31070
- floral sex allocation;
- flower dimorphism;
- mating environment;
- pollen limitation;
- pollen receipt;
- pollinator preference;
- sexual system
- Gynomonoecy, a sexual system in which plants have both pistillate (female) flowers and perfect (hermaphroditic) flowers, occurs in at least 15 families, but the differential reproductive strategies of the two flower morphs within one individual remain unclear.
- Racemes of Eremurus anisopterus (Xanthorrhoeaceae) have basal pistillate and distal perfect flowers. To compare sex allocation and reproductive success between the two flower morphs, we measured floral traits, pollinator preferences, and pollen movement in the field.
- Pollen limitation was more severe in pistillate flowers; bee pollinators preferred to visit perfect flowers, which were also capable of partial self-fertilization. Pollen-staining experiments indicated that perfect flowers received a higher proportion of intra-plant pollen (geitonogamy) than pistillate flowers. Plants with greater numbers of pistillate flowers received more outcross pollen. The differential reproductive success conformed with differential floral sex allocation, in which pistillate flowers produce fewer but larger ovules, resulting in outcrossed seeds.
- Our flower manipulations in these nectarless gynomonoecious plants demonstrated that perfect flowers promote seed quantity in that they are more attractive to pollinators, while pistillate flowers compensate for the loss of male function through better seed quality. These results are consistent with the outcrossing-benefit hypothesis for gynomonoecy.