seed dispersal

Every plant has a unique way of seed dispersal. this technique is basically used by the plants to increase the introduction of plants at new places .

plants undergo some modifications and adaptation in accordance to the environment for more efficient way of seed travel.
there can be adaptations like flaying or parachute seeds , the examples are shown in the ppt.

1. NAME : ROHINI KANBARKAR CLASS: BSc 3 SEM. (B) SUBJECT : BOTANY GUIDED BY : MRS. POOJA MELVANKI

2. DEFINITION : Seed dispersal means the dissemination of seeds to various distances from their parent plant . OR Seed dispersal  is the movement, spread or transport of  seeds  away from the parent plant.

3. Reasons for seed dispersal If numerous seeds fall and germinate right beneath the parent plant ,they have to compete for light, water and nutrients from the soil .  Group of seeds can be easily detected and destroyed by the animals . Increase chances of back – crossing , consequently poor progeny .

4. Importance of seed dispersal Decrease the competition between the parent plant and the seeds. It decrease overcrowding so avoids competition for environment, light, space and nutrients Reduces the amount of seeds lost due to predation Increase variety in progeny .

5. SEED DISPERSAL BY WIND : ANEMOCHORY Some seeds are carried to the new place by the means of wind . Seeds from plants like dandelions and cottonwood trees are light and have feathery bristles and can be carried long distances by the wind . Some plants, like kauri and maple trees, have ‘winged’ seeds.  Needs large number of seed production . Presence of wings, hairs and light weight

6. Dandelions : hairy parachutes maple : winged seeds cotton seed : hairy parachutes

7. Orchids Produces about 700 million seeds per plant. DUST SEEDS ( tiny seeds)

8. Water dispersal : HYDROCHORY S eeds of plants which grows near water bodies such as beach , river etc. use water as a means of dispersal. The seeds float away from the parent plant when fall into the water. Example, water lily , coconut Have special devices to prevent the water penetration which helps in floating for long period of time and distance .

9. Coconut Coconuts can travel thousands of kilometers to reach the away from the place they started and still germinate . Smooth and waterproof epicarp . Original home of coconut is said to be MALAYSIA.

10. Animal dispersal : ZOOCHORY BY EATING THE FRUITS : Animals like birds commonly eat the fruit bearing seed . only juicy part is digested and seed travels through the digestive system of bird then is excreted out to develop in new plant at new place . 2. EXTERNALLY CARRIED BY ANIMALS : Seeds sticks to the body surface of animals or held in their mouth .

11. EXPLOSIVE DISPERSAL : AUTOCHORY Presence of pods which explodes when seed ripe resulting in violent ejection of seeds at far distances. Example, viola, peas , gorse and beans have seedpods that dry out once the seeds are ripe. When dry, the pods split open and the seeds scatter.  Gorse : popping pods of seeds , in summer

12. Arceuthobium : explosive seed

13. THANK-YOU