University Of Fayoum Faculty Of Science Department Of Botany

University of Fayoum Faculty of Science Department of Botany

PALYNOLOGY

For 2nd year Geology Students & 3rd year Botany Students

Prepared by: Asmaa khamiss Fayoumi

Revised by: Dr. Hesham El-

Introduction Palynology Is the branch of science which, deals with study of pollen grains and spores of the vascular plants. It also comprises the study of the microfossils other than pollen grains and spores, e.g.: cysts or cyst-like bodies of algae or of unknown origin. The word palynology was derived from the Greek verb “palynein”, which means spread around. Palynology- Asmaa Khamiss & Hesham Elfayoumi

What is pollen? Pollen grains represent the microscopic reproductive units produced inside the anther of the flower. 2. Usually oval or rounded in shape. 3. Pollen grains are spread around from the male organ to pollinate the female organ in the same flower (self pollination) or in another flower of the same species (cross pollination), then fertilization takes place, this spreading process called anthesis. 4. Pollen grains are spread around by the wind, insects, animals, water, or even by the human. 1.

Palynology- Asmaa Khamiss & Hesham Elfayoumi

T.S. through the anther showing two lobes and four pollen sacs containing the pollen grains.

Palynology- Asmaa Khamiss & Hesham Elfayoumi

Pollen

Spore

1- There are two types of the microscopic reproductive units: * Male (microspores) known as pollen grains. * Female (macrospores) knows as ovules. 2- Produced by the higher vascular plants: *Gymnosperms and *Angiosperms.

1- There are two types of the microscopic reproductive unit : * Male (microspores). * Female (megaspores).

3- Produced inside the pollen sacs .

3- Produced inside certain structures called sporangia.

2- Produced by the lower vascular plants : *Pteridophytes and *Bryophytes.

Palynology- Asmaa Khamiss & Hesham Elfayoumi

Life cycle of the flowering plants carrying Adult plant (2n)

anthesis Anther(1n)

Carpel(1n)

Seedling

pollen grains pollination

Germination of the pollen on the stigma and producing of the pollen tube Fertilization

Developed into Embryo (2n)

Zygote (2n)

Palynology- Asmaa Khamiss & Hesham Elfayoumi

Palynology- Asmaa Khamiss & Hesham Elfayoumi

Morphological characters of pollen grains and spores: # Sporoderm (stratification of pollen wall) Sporoderm Perine Less resistant to decay.

Exine Resistant layer made of sporopollenin, consists of:

Sexine

Intine The inner to the exine made of cellulose.

Nexine

Outer sculpturing exine. exine.

Inner sculpturing

Tectum

Columella

Partially covering Layer.

Rod-like elements.

Outer Layer Inner Layer

Palynology- Asmaa Khamiss & Hesham Elfayoumi

Structure of pollen wall (Sporoderm)

Spin (sculpture) Tectum Columella Bacula Nexine 1 Nexine 2 Intine Tectum + Columella + Bacula = Sexine. Nexine 1 + Nexine 2 = Nexine. Sexine + Nexine = Exine (Sporopollenin). Palynology- Asmaa Khamiss & Hesham Elfayoumi

Palynology- Asmaa Khamiss & Hesham Elfayoumi

# Shapes of pollen grains: 1- Circular

2- Elliptic

3- Triangular

Palynology- Asmaa Khamiss & Hesham Elfayoumi

4- Quadrangular

5- Quinquangular

6- Rectangular 7- Rhombic Palynology- Asmaa Khamiss & Hesham Elfayoumi

# Apertures (NPC–system) 1- Pollen grain germinates by producing a germination tubes, which penetrate the sporoderm through certain holes called apertures.

2- The number, shape and distribution of these apertures vary from one species to another. Palynology- Asmaa Khamiss & Hesham Elfayoumi

3- When sporoderm has no obvious apertures, the pollen grain described as “in-aperturate” (atreme).

4- A special system has been devised to describe the Number, Position, and Character of the apertures in pollen grains, it generally known as NPC-system.

Palynology- Asmaa Khamiss & Hesham Elfayoumi

1- Number of the apertures: Pollen grains may have:  One aperture  Two apertures  Three apertures  Four apertures  Five apertures  Six apertures  Many(>6)

and called and called and called and called and called and called and called

Palynology- Asmaa Khamiss & Hesham Elfayoumi

mono….. bi……… tri……… tetra…… penta…. hexa….. poly……

2- Position of apertures: There are three different positions: Polar pollen grain has only one aperture situated at one pole, or two apertures at the two opposite poles. Zono… (equatorial): where there are three or more apertures distributed at equal distances around it’s equatorial line. Panto… (global): in which the apertures are scattered allover the pollen wall at equal or un-equal distances. Palynology- Asmaa Khamiss & Hesham Elfayoumi

3- Character of apertures: Apertures may be Simple Pore Rounded or more or less circular in surface view.

pore is

Compound Colpus elongated or fusiform apertures. 3-branched furrow (trichotomocolpate). orate, more or less rounded apertures.

Colporate which is a combination of pores and colpi, where the colpus is in the outer layer of the exine, while the in the inner layer .

Palynology- Asmaa Khamiss & Hesham Elfayoumi

For example: if we have this pollen grain

We can describe it as: Poly-panto-porate It means that: this grain has many pore-like apertures, which scattered allover the grain.

Palynology- Asmaa Khamiss & Hesham Elfayoumi