Plant Sex: Mating Systems, Pollination, and Clonality Flashcards
Asexual reproduction
Produces genetically identical daughter plants (ramets)
Sexual reproduction
Produces genetically distinct daughter plants (genets)
Vegetative reproduction structures
Stolen
Rhizomes
Bulbs
Suckers
Layering
Apomixis
Stolon (runner)
Branches on surface
Rhizome
Underground stem
Bulbs (corm)
Underground rosette
Suckers
Buds forming on shallow roots
Layering
Stems form adventitous roots
Apomixis
Asexual seed production
Clone structure
Phalanx (clumping)
Guerilla (spreading)
Phalanx
Tightly packed ramets
Guerilla
Widely spread ramets
Phalanx vs guerilla tactics
Phalanx is better at exploiting high nutrient resources
Guerilla is better at finding new patches
Clonal integration
An initial investment of carbon and nutrients from parent as a new ramet forms. Some clones break apart rapidly while others maintain connections for long time spans
Benefits of integration
Avoid kin competition
Integrate environmental conditions over entire clone
Improve defensive signaling
Benefits of separation
Increase lifespan of individual clones
Decrease cost of maintaining connection
Allow independent timing of flowering
Agamospermy
Asexual production of seeds (apomixis) which lacks recombination
Mating systems
Governs with whom a plant mates
How are plants divided in the mating system?
Autogamous
Facultative self compatible
Allogamous
Autogamous
Inbreeding, flowers that always self-fertilize
Facultative self compatible
Can either self fertilize or outcross
Allogamous
Outbreeding, plants that never self fertilize
Autogamous mating systems
Autogamy
Geitonogamy
Cleistogamy
Autogamy
Fertilization within same flower
Geitonogamy
Pollen movement from 1 flower to another on same plant
Cleistogamy
Flowers that never open, entirely self pollinated
Hermaphroditic plants
Most common of all plant species where the male and female are on same plant. There are often mechanisms to avoid self fertilization
Monoecious flowers
Separate sexed flowers
Hermaphroditic flowers
Bisexual flowers
Heterospecific pollen tranfers
Pollination typically requires conspecific pollen. Heterospecific pollen transfer can reduce pollination success
Outbreeding mechanisms (pollination syndromes)
Wind
Animals/insects
Water
Wind pollination
Common among coniferous trees and grasses (sometimes angiosperms)
Wind pollinated flower characteristics
Lack of pollinator attractors
Exposed anthers and small pollen grains
Feathery stigma to catch pollen
Masting
Wind pollinated plants synchronize reproduction
2 main hypothesises about masting
Seed predator satiation
Improved pollination efficiency
Optimal environmental conditions
Animal based pollination
Animals/insects visits flowers to get rewards and thus transfer pollen among or within individuals
Pollinator attraction cues
Infloresence shape and size
Flower colour
Flower rewards
Floral scents
Auditory cues
High heterospecific floral densities can __________ heterospecific pollen transfer
Increase
Pollinator fidelity
Plants try to limit heterospecific pollen transfer by increasing pollinator fidelity
Vertebrate pollination
Incredibly important for pollination of some species
Deceptive orchids
Provide chemical cues to trick insects into thinking they are finding a mate
Nectar robbers
Cut into side of flowers to get nectar without pollinating the plant
Cost of males
An asexual female producing only daughters will have a greater fitness than a sexual counterpart
Loss of local genetic adaptation
A plant reaching reproductive age at a location with environmental conditions to which it is adapted to, so why risk changing a good thing
Major benefits of sexual reproduction
Genetically different offpring which allows them to deal with fluctuating environments, sibling competition, and host-pathogen interactions
Allocation to sexual reproduction may be more likely when resources are in _____
Excess
Abandon ship hypothesis
In poor environments, invest all energy in sexual reproduction rather than growth. It increases genetic diversity in offspring and gives them a chance to find a better environment