Ch. 7: Plant Growth and Reproduction Pollination Why flowers vary? Many form mutualism w/ animals Terms Pollination (flowering plants): pollen
Carpel=pistil Terms Fertilization: sperm Pollination
Abiotic: pollen carried Wind Pollination Grasses, temperate trees (Quercus, Carya, Pinus) Not mutualism Carya
A grass Terms Biotic pollination: pollen Floral visitor: Pollinator: puts
Pollination (often) Mutualism Mutualism (+,+) interaction Plant: pollen transferred Animal: reward Reward? Animal Rewards Pollen: hi protein
Also lipids, minerals, starch Renewable Rewards Pollen renewal: sequential anther dehiscence (multiple stamens)
Tony Danzas Masters Study Creosote bush Rewards poricidal anthers (buzz pollination): anthers
Vaccinium (blueberry) Rewards Nectar: Who am I? Rewards
Nectar: 10-60% sugars Amino acids ( Oils/Resins: Rewards Nest materials
cologne (male bee Krameria wax gland: wasp food! Pollination Benefits animal pollination 1) Directed dispersal pollen: Pollination
Benefits animal pollination Directed dispersal aided by learning (decreases handling time) Fosters floral constancy (1 Bumblebee visits to touch-me-not
Pollination Benefits animal pollination 2) Style as selective racetrack stigma style ovary 2 ovules
Pollination Benefits animal pollination 2) Style as selective racetrack
1 pollen grain fertilizes 1 ovule IF: 5 arrive How many fertilize an ovule? Pollen grains stigma pollen tubes
style ovary 2 ovules Pollination Benefits animal pollination 2) Style as selective racetrack Pollen tubes 1N
Pollen grains stigma style ovary 2 ovules
Pollination Benefits animal pollination 2) Style as selective racetrack Pollen tubes 1N If allele recessive: expressed (not masked by dominant allele) Pollen grains
stigma style ovary 2 ovules Pollination
Benefits of animal pollination 2) Style as selective racetrack Pollen grains stigma style ovary 2 ovules
Pollination Style as selective racetrack Ex., Coyote melon Gourd: U.S. deserts. Pollination Style as selective racetrack
Study (2000) showed: 1) 900 pollen grains fully pollinate 2) 1 visit 650 grains/flower. By 2 hours, >4000 deposited 3) Over-pollinated flowers Outcrossing Major benefit sexual reproduction: generate genetic variation Enhanced by mating w/ others (outcrossing)
Why just enhanced? Outcrossing Recall: Crossing over Independent assortment Why just enhanced?
Making gametes by meiosis: 23 pairs chromosomes gives 8 million different combinations Moms and Dad s chromosomes in gametes Outcrossing Favor outcrossing: 1) Dioecy
Outcrossing Favor outcrossing: 2) Floral morphology Heterostyly: Diff. Distyly: 2 diff. morphs perfect
Outcrossing Ex, Gelsemium sempervirens Outcrossing
Favor outcrossing: 3) Floral phenology Protandry: anthers Protogyny: stigma Protandry Outcrossing
Favor outcrossing: 4) Self-incompatibility: stop Pollination syndromes Pollination Syndrome: flower traits & pollinator traits that adapt each to other Disclaimer: We make broad generalizations and exceptions exist to most statements!
Ch. 7: Plant Growth and Reproduction Pollination syndromes Bee pollination Bees: intelligent, agile Good sight (incl. UV light)
good smellers European honeybee Halictid bee Leafcutter bee Bumble bee
Flowers: Pollination syndromes Colorful (not red)
Landing platform: place to Mildly fragrant Often nectar guides: patterns Orchid flower with nectar guides (lines) on petals
Petals in visible light (top) and UV (bottom) Pollination syndromes Fremontodendron decumbens (endangered chaparral shrub) flowers UV reflectance photo (right)
Tony Danza?? Pollination syndromes Beetle pollination Beetles: Clumsy, dumb Poor vision, good smellers Flowers:
Lg (or lg inflorescences) Lite color Smelly (fruity/spicy)
