1. Ch. 7: Plant Growth and Reproduction

2. Terms
Biotic pollination: pollen carried animal--90% flowering plants

3. Terms
Biotic pollination: pollen carried by animal--90% flowering plants
Floral visitor: visits
Pollinator: deposits

4. Pollination as Mutualism
Mutualism (+,+) interaction
Plant gets pollen transferred
Animal gets “reward”
Reward?

5. Animal Rewards Pollen: high protein Also has lipids, minerals, starch
Renewable…

6. Rewards Pollen renewed by:
sequential anther dehiscence (multiple stamens)
Tony Danza’s Masters Study
Creosote bush

7. Rewards poricidal anthers (buzz pollination): anthers have
Vaccinium (blueberry)

8. Rewards
Nectar: (nectar glands: nectaries)
Who am I?

9. Rewards Nectar: 10-60% sugars Amino acids (butterfly flowers)
Renewable!

10. Rewards Oils/Resins: Krameria wax gland: wasp food!
nest construction materials
“cologne” (male bee uses oil: )
larval food (Krameria)
Krameria wax gland: wasp food!

11. Pollination Benefits animal pollination 1) Directed dispersal pollen:
Gene flow!
Record distance?
Tropical orchid

12. Pollination Benefits animal pollination
Directed dispersal: aided by learning ( “handling time”)
Fosters “floral constancy” (visit 1 sp )
Bumblebee visits to
touch-me-not

13. Pollination Benefits animal pollination stigma style ovary 2 ovules
2) Style as “selective racetrack”
1 pollen grain fertilize 1 ovule
Suppose 5 pollen grains arrive
How many fertilize an ovule?
Pollen grains
stigma
style
ovary
2 ovules

14. Pollination Benefits animal pollination stigma style ovary 2 ovules
2) Style as “selective racetrack”
Pollen tubes 1N
If allele recessive, then
Pollen grains
stigma
style
ovary
2 ovules

15. Pollination Benefits of animal pollination stigma style ovary 2 ovules
2) Style as “selective racetrack”
Fittest (fastest) pollen grains
Pollen grains
stigma
style
ovary
2 ovules

16. Pollination Style as “selective racetrack” Ex., Coyote melon
Gourd in U.S. deserts.

17. Pollination Style as “selective racetrack” Study (2000) showed:
1) 900 grains: fully pollinate
2) 1 visit 650 grains/flower. By 2 hr, >4000 deposited
3) Over-pollinated: more vigorous seedlings

18. Outcrossing
Major benefit sexual reproduction: generate genetic variation
by mating w/ others (outcrossing)
Why just enhanced?

19. Outcrossing Why just enhanced?
Making gametes by meiosis: 23 pairs of chromosomes
gives 8 million different combinations of Mom’s and Dad’s chromosomes in gametes

20. Outcrossing
Favor outcrossing:
1) Dioecy

21. Outcrossing Favor outcrossing: 2) Floral morphology
Heterostyly: Diff. stamen/style lengths
Distyly: 2 diff. “morphs” perfect flowers

22. Outcrossing
Ex, Gelsemium sempervirens

23. Outcrossing Favor outcrossing: 3) Floral phenology Protandry: anthers
Protogyny: stigma
Protandry

24. Outcrossing
Favor outcrossing:
4) Self-incompatibility: stop

25. Pollination syndromes
Pollination Syndrome: flower traits & pollinator traits that adapt each to other
Disclaimer: We make broad generalizations and exceptions exist to most statements!

26. Pollination syndromes
Bee pollination
Bees:
intelligent, agile
Good sight (
good smellers
European honeybee
Halictid bee
Leafcutter bee
Bumble bee

27. Pollination syndromes
Flowers:
Colorful (not red)
Landing platform: place
Mildly fragrant
Often nectar guides: patterns
Orchid flower
with nectar
guides (lines)
on petals
Petals in visible light
(top) and UV (bottom)

28. Pollination syndromes
Fremontodendron decumbens (endangered chaparral shrub) flowers
UV reflectance photo (right)
Tony Danza??

29. Pollination syndromes
Beetle pollination
Beetles:
Clumsy, dumb
Poor vision, good smellers

30. Pollination syndromes
Beetle pollination
Beetles:
Clumsy, dumb
Poor vision, good smellers
Flowers:
Lg (or lg inflorescences)
Lite color
Smelly

31. Pollination syndromes
Bird pollination:
Flower-visiting birds:
Agile, long beak
visual: see red
poor “smell”
Hummingbirds (native to Americas) hover

32. Pollination syndromes
Flowers:
red/orange
Nectar (tube)
little No
???
Aloe

33. Pollination syndromes
Butterfly pollination
Butterflies: good vision/smell, long tongue
Don’t hover well
coiled tongue
tongue extended

34. Pollination syndromes
Flowers:
Color varies (blue, yellow, orange)
Landing
Nectar
Phlox
pilosa

35. Pollination syndromes
Bat pollination
Nocturnal: sight good (but it’s dark!)
Good
Agile

36. Pollination syndromes
Flowers
Open night: light color
Lots
Fragrant
May be pendant
Parkia flowers

37. Pollination syndromes
Bat pollination: Mainly tropical
In U.S., saguaro
Saguaro cactus
Saguaro flowers