Monocotyledon reproduction
In order to reproduce they utilize various strategies such as employing forms of asexual reproduction, restricting which individuals they are sexually compatible with, or influencing how they are pollinated.
Clonal propagation is the production or division of vegetative structures which develop into new individuals that are genetically identical to their progenitor.
Monocots constitute the majority of plants with such structures, mainly in the families: Iridaceae, Liliaceae and Amaryllidaceae.
For this reason, most plants have genetic mechanisms to prevent fertilization from pollen grains that are too closely related to the stigma (self-incompatibility).
The mechanisms of breeding systems occur at the molecular level through a biochemical reaction on the stigma that recognizes genetic differences in pollen grains.
[1] Mating with individuals that are too closely related (i.e. with self) may result in inbreeding depression, so it is usually considered advantageous to cross-pollinate intraspecifically, in which case self-incompatibility is utilized.
[5] The most widespread form of self-incompatibility in monocots is gametophytic,[6] meaning compatibility is determined by the genotype of the pollen grain.
There are two described mechanisms of gametophytic self-incompatibility that have been shown to occur in four families of dicots (RNase and S-glycoprotein) but none have been found in monocots.
Heteromorphic sporophytic self-incompatibility, a mechanism in heterostylous flowers, has been shown to occur in only one family of monocots, Pontederiaceae.
[2] Monocot pollen grains are monocolpate, meaning they have one groove; outer surfaces called exines are smooth.
For example, dichogamy, which is the temporal differentiation in the ripening of sexual organs, is common in monocots with both protogynous and protoandrous flowers.
When animal-mediated, sexual organs will be positioned closer spatially and temporally, inverse to the strategies of dichogamy and herkogamy.
In Caulokaempferia coenobialis (Zingiberaceae), pollen is transported via a drop of oil that forms on the anther and slowly slides down to the stigma.
[14] Another orchid, Holcoglossum amesianum, rotates its anther in circles to transfer pollen into its stigma cavity.
Monocot flowers occur with parts having multiples of three; usually there are three stamen, three petals and three sepals (six tepals), and usually just one stigma.
Furthermore, flower structures that evolved to trap insects to accomplish pollination are found in many monocot genera.
[1] Deceptive flowers that do not offer actual rewards are much more widespread in monocots than dicots, with the most common perpetrator being the orchids.
Most wind-pollinated plants do not produce nectar, attractive scents, or petals because they are not adapted to pollination by animal vectors.
When pollination is zoophilous flowers can be fragrant and attract large numbers of pollinator-collecting bees to congregate around the inflorescence and take advantage of this new and abundant source of pollen.
