Plant reproduction - Reproduction means - Sexual means - Asexual means -

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1 Plant reproduction - Reproduction means - Sexual means - Asexual means -

2 Plant reproduction - Reproduction means - Plants producing offspring of the same species as themselves Sexual means - Reproduction which involves the meeting and joining of two different sex cells (gametes) Asexual means - Reproduction which does not involve the meeting and joining of two different sex cells (gametes)

3 When plant gametes meet and join, this involves pollination and fertilisation insect Pollination wind small nectar bright Sticky pollen few pollen scent Parts outside green Parts inside Light pollen many pollen

4 Pollination has happened the pollen is on the stigma Fertilisation has not happened What has to happen for fertilisation to take place?

5 The pollen tube grows down into the ovary to join with the egg. Fertilisation has happened when the nucleus from the pollen joins with the egg.

6 In the flower. In the fruit Fertilised egg Embryo plant in the seed

7 So, the first way of growing a new plant is plant a seed.

8 How do conditions affect seed growth? Test tube Filter paper cylinder seeds water What condition could we alter? How? What would we need to keep the same?

9 I would know when a seed had germinated by... To find the condition which was best, I would need to count...??

10 Vegetative reproduction This is where plants produce new plants without sex. Only one parent plant is involved in the production of the new plants.

11 Vegetative reproduction Many plants can reproduce without sex. One example is the onion.

12 An onion is an example of a bulb. It grows in the soil, with roots growing down to get water, and leaves growing up to get light. It reproduces by growing new bulbs from the side of the old bulb.

13 The parts of a bulb are - The new leaves grow out of the bulb to get light Swollen leaves. These store food, to provide energy when the bulb starts to grow. The food it contains is starch. The stem is very short and never grows out from the bulb. The roots grow down to get water

14 This is a potato tuber. It is found under the soil. It is full of food to provide energy for when the new plant starts to grow. The food it contains is starch. The eyes are buds, where the new shoots grow from. They use the energy from the tuber to grow up into the light.

15 These are sprouting tubers, where the new plants have started to grow, They are using up the starch stored in the tuber.

16 The original tuber shrivels up as the starch is used up New tubers grow at the end of stalks. The new plants will grow from these next spring One old tuber produces many new tubers by the end of the year.

17 The Mexican hat plant grows complete miniature plantlets on the edges of its leaves. These fall off into the soil and grow into new plants.

18 Creeping butter cup reproduces by making runners. These grow out from the parent and produce plantlets every time they touch the ground. Parent plant runner New plant

19 Parent plant runner New roots on new plantlet

20 Rhizomes are long creeping stems which grow from the plant. Every so often, a new shoot and new roots develop along the rhizome. Each of these can develop into a new plant. Parent plant rhizome New plant The rhizome supplies the new plant with food and water while it is growing. Sometimes the rhizome grows under ground. This is what happens with couch grass.

21 Spider plants grow new baby plants at the end of long runners. When these touch the ground, new roots develop so that the new plant can get water from the soil. While it is still growing, the new plant gets food and water from its parent. This helps it survive.

22 Using Vegetative reproduction Gardeners can make use of a plant s ability to grow new part and grow into a new plant to increase the numbers of plants. This is artificial propagation.

23 This plant is an African Violet. It has lots of healthy green leaves growing from its base. The gardener can use each leaf to make a new plant. This is called taking a leaf cutting.

24 Take the leaf and its stalk from the plant as close to the base as you can. Plant the leaf in moist compost After a few days, new plants start to appear from the base of the leaf.

25 Other ways of taking leaf cuttings are to pin the whole leaves down onto the surface of compost New roots will grown from the under side. Sometimes you do not need the whole leaf. It can be cut into pieces, and these can be planted in compost. They will then grow new plants.

26 Layering is when a plant is pinned to the soil to make it produce new plant Cut a nick in a stem near a node. Peg the cut surface down onto the soil. It will start to grow roots and the bud will start to grow into a new shoot. The connection to the parent plant can then be cut.

27 You can use a whole stem to make a cutting. Cut across the stem in a slanting cut. Do this just below a node. Dip the cut end into rooting powder to encourage it to grow roots.

28 Put the cut stem into moist compost in a container Label the cutting.

29 Put the cutting into a propagator or tank to keep it warm and stop it drying out Keep it well watered. If you do not have a tank, you can put the whole cutting in a clear plastic bag to let the light in, but keep it nice and moist.

30 A final method of artificial propagation is grafting. Grafting is where the top of one plant is joined to the bottom of another. Plants do not have immune systems, so do not reject foreign tissue, as an animal wood. As long as both plants belong to the same family, the cut surfaces from each will grow into each other and fuse the parts of the plant together.

31 In roses, the bud of one plant is grafted into the root system of another. The bud will grow on to produce the shoot, and the flower at the end. This means that the part of a rose with a particular flower can be grown on a strong, disease resistant root. You have combined the best features of two different plants by simply fusing them together. bud Slit in the bark of a root stock from a different rose

32 This is the bud two weeks later. The leaves and shoot have started to grow from the bud. These will eventually grow to form the whole stem and the important flowering shoot.

33 Stem grafts are used in growing fruit trees. This time a whole shoot, the part which will make the fruit, is joined on to the existing strong root stock of a fruit tree. You are combining a good fruit growing shoot with a strong, disease resistant root.

34 This fruit tree has two shoots which were grafted onto a single root stock. This gives two stems producing fruit on the root of a different plant one which had a stronger, disease resistant root. If you want to be really cool, you could graft a pear shoot and an apple shoot onto the same root. What would you get? One shoot would grow apples, the other would grow pears all on the same tree!

35 The End