Reproduction in plants

1
Reproduction in plants
Chptr 38 Chptr 39, 818-823 Chptr 48, 1045-1046
2
Asexual reproduction

• Cellular fission
• Budding
• Vegetative propagation
• rhizomes
• stolons
• bulbils
• Apomixis
• Cloning

Fig 38.15
3
Cloning by tissue culture
Fig. 38.16
4
Sexual reproduction

• Alternation of generations

5
Generalized Life Cycle
2n
1n
Figure 29.6
6
Diploid Life CycleObelia
Figure 33.7
7
Haploid Life CycleChlamydomonas
Figure 28.24
8
Haplo-diploid Life Cyclegeneralized
Figure 30.1
9
Haplo-diploid Life Cyclemoss
Figure 29.16
10
Haplo-diploid Life Cyclefern
Figure 29.23
11
Haplo-diploid Life Cycleconifer
Figure 30.9
12
Angiosperm life cycle
Figure 30.17
13
Angiosperm life cycle
Figure 38.1
14
Angiosperm Flower Structure
Figure 38.2
15
Flower structure variation

• Complete flowers all parts present
• Incomplete flowers at least one part missing
• Bisexual (Perfect flowers) both male and female
  parts present
• Unisexual (Imperfect flowers) male or female
  parts missing
• Monoecious both male and female flowers on same
  plant
• Dioecious male and female flowers on different
  plants

16
Gametophyte Development
Figure 38.4
17
Embryo Sac(female gametophyte)
18
Pollen grains-male gametophytes-
19
Transfer of pollen-agents-

• Wind
• Water
• Insects
• Birds
• Mammals

20
Self-incompatibility-genetic recognition-
Figure 38.7
21
Sporophytic self-incompatibility mechanism
Figure 38.8
22
Double Fertilization
Figure 38.9
23
Early Plant Development
Figure 38.10
24
Seed Structure
Figure 38.11
25
Fruit Structure
26
Generalized fruit types

• Fleshy - proliferation of ovary wall into soft
  tissue.
• Dry - ovary wall becomes hardened at maturity.
• Indehiscent - does not split at maturity
• Dehiscent - splits along predetermined sutures at
  maturity.

27
Seed Germination
Fig 38.14
28
Biological Rhythms
29
Components of Biological Rhythms
30
Periodicities

• Circadian - daily
• Circatidal - with tidal highs or lows
• Circalunar - phased with moon
• Circannual - yearly
• Supraannual - greater than one year

31
Endogenous clock

• Free running - periodicity in absence of external
  signal (more or less than 24 hrs.)
• Temperature compensated - changes little in
  periodicity with change in temperature (Q10 ?
  1.0)
• Entrainment - setting periodicity with external
  signal.
• Zeitgeber - external signal to which endogenous
  clock is set (generally light-dark).

32
Free Running in Northern Flying Squirrel
Fig. 48.23
33
Entrainment of Infant
34
Entrainment through pineal glandin blinded House
sparrow (Passer domesticus)
35
Photoperiodism in Plantsshort day and long day
plants
Figure 39.22
36
Hypotheses for measuring day length for
circannual events
37
Hour-glass hypothesisdependent on a chemical
which converts to one form rapidly inlight, and
slowly reverts during dark
Rapid reconversion during light
Slow conversion during dark
light
dark
No response
Amount needed for response
Long day
Response
Short day
38
Clock hypothesis
response
No response
39
Phytochrome
Figure 39.19
40
Phytochrome conversion
Figure 39.20
41
Interaction of red and far-red light
Figure 39.23
42
Floral Induction
Figure 39.24
43
Preconditioning

• Opposite day length
• Vernalization - cold treatment
• Soil moisture

44
The End