“basal angiosperms”, and plant breeding systems
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“Basal angiosperms”, and plant breeding systems
Soltis et al., 2011
Monocots'
ANITA'grade'
Magnoliids'
Ranunculaceae'
Angiosperm phylogeny
�Basal angiosperms�
tricolpate pollen
1 cotyledon ANITA grade • Amborella • Nymphaeaceae • Illicium • Trimenia • Austrobaileya
Angiosperm phylogeny
A – N – A
http://botany.csdl.tamu.edu/FLORA/tfplab/lilyp.gif
Nymphaeaceae
8 genera, 70 species (Nymphaea)
Victoria sp., Amazon water lily Nymphaea spp.
8 genera, 70 species (Nymphaea) Habit: Stems: Leaves:
Nymphaeaceae
Aquatic
Air canals
Long petioles, submerged or floating to emergent
Nymphaeaceae
Symmetry: Perianth parts: Stamens: Pistils: Ovary position: Fruit type:
radial
4-12 tepals, free; petal-like staminodes
3-many, laminar
1-many (1-many carpels/pistil)
superior or inferior
aggregate of nuts, or follicle, berry, fleshy capsule
�Basal angiosperms�
tricolpate pollen
1 cotyledon
Angiosperm phylogeny
Magnolia x soulangeana
Magnoliaceae
2 genera, 220 species (Liriodendron, Magnolia)
Liriodendron tulipifera
2 genera, 220 species (Liriodendron, Magnolia) Habit: Leaves:
Magnoliaceae
Trees or shrubs Evergreen or deciduous
Alternate, simple, entire (lobed in Liriodendron) Ethereal oils
Magnoliaceae
Symmetry: Perianth parts: Stamens: Pistils: Ovary position: Fruit type:
radial
6-many tepals, free
many, laminar
many simple pistils = many free carpels
superior
aggregate of follicles (Magnolia), or samara (Liriodendron)
• Insect-pollinated • Radially symmetric • Perfect • Floral parts:
• Several to many • Spirally arranged • Distinct (unfused)
• Stamens laminar • Pistils simple • Ovaries superior
“Basal” angiosperms
Flowers of early angiosperms
�Basal angiosperms�
tricolpate pollen
1 cotyledon
Angiosperm phylogeny
�Basal eudicots�
Asterids Rosids
Eudicots (Tricolpates)
Angiosperm phylogeny
Ranunculaceae
47 genera, 2,000 species
47 genera, 2,000 species Habit: Leaves:
Ranunculaceae
Usually herbaceous
Usually alternate (often all basal), simple to dissected to compound Usually lacking stipules
Ranunculaceae
Symmetry: Perianth parts: Stamens: Pistils: Ovary position: Fruit type:
radial or bilateral
5 sepals, 5 petals (or 4-many tepals), free
many
usually 5-many, simple
superior
usually aggregate, sometimes a berry
Plants vs. Animals
Plant breeding systems
bisexual
sex = dynamic
non-mobile
body plan = modular
unisexual
sex = fixed
mobile
body plan = fixed
Asexual reproduction
Vegetative reproduction: does not involve flowers Agamospermy (apomixis)
Flowers produced
Embryo produced clonally
No fertilization
• Locally adapted offspring • Less reproductive effort • Reproductive assurance
Asexual reproduction
• Little genetic variability • Narrow range of environmental
tolerance • Limited dispersal (except
agamospermy)
Advantages
Disadvantages
Sexual reproduction
Self pollination
Self pollination
Cross pollination
Self pollination: pollen transfer within an individual plant Self fertilization: fertilization of egg by sperm of same individual plant
Sexual reproduction: selfing
Self pollination: pollen transfer within an individual plant Self fertilization: fertilization of egg by sperm of same individual plant
Sexual reproduction: selfing
• Double genetic contribution to offspring
• Locally adapted offspring • Less reproductive effort • Reproductive assurance
• Inbreeding depression • Little genetic variability • Narrow range of environmental
tolerance
Advantages
Disadvantages
• Capable of self-fertilization • Ovule may be fertilized by pollen from
the same plant, or from different plants
• Only capable of cross-fertilization • Ovule cannot be fertilized with pollen
from the same plant
Self-compatible (SC)
Self-incompatible (SI)
Sexual reproduction: outcrossing
• How might you discover whether an unknown plant reproduces by self-fertilization, cross-fertilization, or agamospermy?
• You may perform any of the following experiments to determine whether seed is set: – Pollinator exclusion – Remove stamens before pollen is released – Artificial self-pollination – Artificial cross-pollination
• What do you predict will happen in each case?
Class discussion – breeding systems
Asexual reproduction Sexual reproduction
Agamospermy SC SI
Pollinator exclusion
Emasculation
Artificial self-pollination
Artificial cross-pollination
Will seed be set?
Pollen released before stigma is receptive
Stigma receptive before pollen is released
Temporal separation of male and female
Functions promoting outcrossing in plants
Protandry Protogyny
Within flowers Between flowers
Functions promoting outcrossing in plants
Spatial separation of male and female
Heterostyly Monoecy/dioecy
Sexual reproduction: outcrossing
• High genetic diversity • Avoid expression of deleterious
recessive alleles • Broad range of environmental
tolerance
• Reproduction less likely • Dependent on pollinator • Dependent on population
density
Advantages
Disadvantages
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