Reproduction in Angiosperms Plants (Class 9 Science Materials) – There are various ways of reproducing large groups of plants. At least it can be grouped into 3 (three) major groups, namely:
- seed plants (Spermatophyta),
- fern (Pteridophyta),
- moss (Bryophyta).
Reproduction in seed plantsSpermatophyta) itself is divided into closed seed plants (Angiosperms) and open seed plants (Gymnospermae).
Angiosperm Plant Reproduction
Mango, rambutan, coconut, rice, and corn plants are examples of the Angiosperm plant group. Angiosperm plants or closed seed plants are plants that have the characteristics of the ovary being in the ovary (ovary).
The fruit will be the enlarged part of the pistil which is composed of fruit leaves (carpel). The ovule will then develop into a fruit and the ovule will develop into a seed.
Angiosperms plants reproduce vegetative and reproduction generative.
Vegetative Reproduction in Angiosperm Plants
Vegetative propagation is propagation using plant parts such as roots, stems, or leaves. Vegetative propagation of plants can produce new individuals without involves the process of fertilization (the process of fusion of the nucleus of the sperm cell with the nucleus of the egg to form a zygote).
Plants can reproduce vegetatively because plants have cells that have the ability to develop into various types of cells that make up plant tissues and organs called meristem cells. Offspring resulting from vegetative propagation have the same nature or character as the parent trait.
1) Natural Vegetative Reproduction
Natural vegetative reproduction is the reproduction of plants with their body parts without human assistance. The following are various ways of natural vegetative reproduction.
Some plants reproduce by budding on stems in the soil. Stems that are in the soil are called rhizomes. Some examples of plants that reproduce by rhizomes are ginger, turmeric, galangal, and temu lawak.
On grass and some other crops, such as strawberries and stems there are stems that creep on the ground. The stems of plants that creep on the ground are called stolon (griggy). Shoots can grow on the books of the stolons. When the shoot is separated from the parent plant, the shoot is able to grow into a new individual.
c) Umbi Lapis
An example of a bulb is found in red onions. The layers contained in shallots are called tubers, because they show a multi-layered arrangement consisting of thickened, soft, fleshy leaves and a small stem at the bottom of the tuber called a disc. It can be said that the tuber (bulbus) is a modification of stems and leaves.
In plants that reproduce by tubers, there are side buds. The side buds that grow are usually small tubers, clustered around the parent tuber. This part is called cloves or tubers. If the clove is separated from the parent, it will produce a new plant.
d) Tuber Stems
On the surface of the potato, there will usually be buds. Under conditions that are suitable for growth, these buds will form shoots and produce new plants.
Potatoes are one example of a plant that has swelling on the stem in the soil and contains food recommendations. Such stems are called stem tubers.
Stem tubers not only serve to store food reserves but also function for reproduction. Sweet potato plants can also reproduce using stem tubers.
e) Leaf Adventive Bud
An example of a plant that reproduces with adventitious leaf buds is the cocor duck. At the edge of the leaf there are cells that are always dividing (meristem cells). In such a part of the leaf can form a bud.
Buds are prospective buds that consist of prospective stems and prospective leaves. The buds found on the edges of the leaves are called adventive leaf buds or wild buds on the edges of the leaves.
2) Artificial Vegetative Reproduction
Artificial vegetative propagation is vegetative propagation of plants carried out with human assistance. The following are various kinds of activities that humans can do to help artificial vegetative propagation of plants.
Grafting can be done by peeling off the bark of a woody plant stem, then wrapping it with soil and wrapped in coconut fiber or plastic, so that roots grow. If the part of the peeled skin has grown roots, then the stem can be cut and planted in the ground.
Plants produced from grafts have parent-like properties and bear fruit quickly. However, the roots of this plant are not strong enough.
Ducking can be done by immersing the plant stalk into the ground, so that the part that is embedded in the soil grows roots. If the roots have grown, the plant can be separated from the parent.
Cuttings are an artificial vegetative propagation method by cutting (separating from the parent) a part of the plant and then planting it to produce new individuals, for example to plant cassava using the stem or called stem cuttings. Breadfruit plants can be propagated by using root cuttings.
Sexual Reproduction in Angiosperm Plants
In sexual reproduction, sperm and egg cells are fertilized, forming an embryo that is stored in the seed. Seeds can grow and develop into new plants.
Traits of offspring (new plants) can be obtained from the combination of the characteristics of the two parents. This causes the hereditary nature of generative reproduction to vary.
1) Pollination (Polination)
Bees or butterflies help flowers in pollination. Pollen is attached to the bee’s feet. When the bees move, the pollen that is attached to the bee’s feet can attach to the stigma. The process of attaching pollen to the stigma is called pollination.polinasi).
The function of each part of the flower is as follows:
- Flower stalks. The flower stalk is at the bottom of the flower. The function of the flower stalk is to support the flower and connect it to other plant parts.
- Flower base. Serves as a place to attach the flower crown.
- Flower petals. It is the outermost part of the flower that covers the crown when it is still a bud. The function of the flower petals is to protect the flower crown when it is still a bud. The flower petals will open when the crown blooms.
- Flower Crown. Is the part of the flower that has the most beautiful shape because it has a certain color. The function of the flower crown is to attract insects. The presence of insects that perch on flowers will help the pollination process.
- Stamens. Is the male genitalia, consisting of anthers, anthers, and pollen. The stamens produce pollen which is useful for the fertilization process.
- Putik. Is the female genitalia, consisting of the stigma, pistil stalk, and ovary. The pistil produces ovum cells that are useful for fertilization to produce seeds.
Types of pollination based on the type of intermediary:
Plants with small flowers, the number of flowers are large and light, and do not produce nectar or odors are some of the characteristics of plants whose pollination is assisted by the wind. Wind-assisted pollination is called anemogamy.
Sunflowers have an attractive and bright color that is yellow, and produce nectar. The characteristics of sunflowers and flowers that have similar characteristics are very attractive to insects, such as bees, to perch and suck nectar.
Generally, the pollen produced by these flowers is sticky so that it is easily attached to the feet of insects. In this way, insects also transfer pollen to the pistil. Pollination that occurs with the help of insects is called entomogamy.
Ornitogamy is pollination assisted by birds. Plants that are pollinated by birds generally have large flowers, bright red in color, odorless, produce large amounts of nectar, and trumpet-shaped flower crowns, such as cangkring or dadap flowers (Erythrina variegata).
Chiropterogamy is pollination assisted by bats. The characteristics of flowers whose pollination is assisted by bats are to produce nectar, have attractive colors, produce odors, and bloom at night, such as cactus plants.
Orchid is a type of plant whose pollination is assisted by humans. Plants whose pollination is assisted by humans are usually two-house flowers, meaning that in one tree there are only male flowers or only female flowers. Anthropogamy can also be done if the pollen of a plant is difficult to meet the pistil, making it difficult to self-pollinate.
In addition to orchids, plants whose pollination is assisted by humans, such as vanilla and salak. In the pollination process, pollen can come from the flower itself or from other flowers that are still in the same species.
Based on the origin of pollen, pollination can be divided into several types.
- Self-pollination (autogamy), ie if the pollen attached to the pistil comes from the flower itself.
- Neighbor pollination (geitonogamy), ie if the pollen attached to the pistil comes from other flowers on the plant as well.
- Cross pollination (allogamy/xenogamy), ie if the pollen attached to the stigma comes from the flowers of other plants and the plant from pollen is still classified as the same type.
- Bastar pollination (hybridogamy), ie if the pollen attached to the stigma comes from flowers on other plants of different types or at least has one different trait.
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