URL: http://flowerpowerlab.wikispaces.com/azalea1234

Group members: Louisa, Dima, Sian and Neil

Azaleas are a species of plant forming two subgenera of the Rhododendron‚Äč genus.

Plant species: Azalea
Plant family: Ericaceae

Pollination and fertilisation
Pollination occurs in azaleas with the aid of pollination vectors, mostly bees and other insects. The insects carry the pollen from the stamen of one flower to the stigma of another. The pollen then travels down the pollen tube (within the style) to the ovary, where fertilisation occurs. After fertilisation, an embryo is formed and develops into a seed.

Floral Morphology
The flowers were dissected (including removal and separation of petals, stamens and pistil) to examine the floral morphology.
The azalea flower contains both male and female structures. The female structure is the pistil, consisting of the stigma, style and ovary. The pistil is located in the centre of the flower, surrounded by several of the male structures, the stamens. The stamens appear slightly thinner than the ovary, but are similar in structure. The pollen is located on top of the stamen in anthers, exposed to both the air and organisms which is beneficial in promoting pollination.


Azalea flower:

azalea flower structuree.png



Stamen (male) structures:

Stamen and anther. png.png


Pistil (Female) Structure:

PISTIL diagram.jpg


Pollen Morphology
The pollen was removed from the anthers, placed on a slide and examined under a compound microscope to examine its structure.
The pollen of an Azalea is a small, round structure. It is contained in pollen grains in the anthers on top of the stamens (male reproductive structures), surrounding the pistil in the centre of the flower.
Each flower contains around 5-8 stamens, each containing many pollen grains, and such, the pollen is fairly abundant in Azalea flowers.

Pollen Structure:

pollen structureeeeeee.JPG


Nectar Characterisation
Azaleas do not contain nectar, and as such use other methods, such as flower colour and pollen, to attract pollinators. The bright colour of the petals could be an attractant for organisms such as birds and insects.
However, the lack of nectar makes it unlikely that birds are the main pollinators of the plant. The pollen itself can be a reward for many insects, and as such, it is likely the azalea flower is mainly pollinated by insects.


Variability of floral morphology
Callipers were were used to measure the various parts of the flowers.


Flowers


Petals


Height (mm)
Width (mm)
Height (mm)
Width (mm)

29.6
39

25
18

33
42

25
15

30
39.4

20
16

27.7
35

24
15

27
32

29
17
AVERAGE
29.46
37.48

24.6
16.2
SD
2.34478144
3.956260861

3.209361307
1.303840481







Stamen


Leaves


32


Height (mm)
Width (mm)

27.7


28
14

31.6


33
10.5

24.3


35
19

31


31.1
12
AVERAGE
29.32


20.1
14.1
SD
3.279786578

AVERAGE
29.44
13.92



SD
5.823486928
3.210451682