Reproduction is the biological process through which living organisms generate additional members of their species. There are two methods for plants to reproduce: asexually and sexually. Sexual reproduction in plants is characterised by alternating generations of multicellular haploid and diploid cells. The female gametophyte in angiosperms is the embryo sac, whereas the male gametophyte is the pollen. The haploid egg and sperm combine to generate diploid zygotes, which grow into new sporophytes. Asexual reproduction produces progeny without meiosis or gamete fusion, and the plant reproduces via tubers, bulbs, corms, and other vegetative elements. Occasionally, a third form of reproduction, apomixis, is discernible. Apomixis is the process by which new individuals are formed from a plant’s sexual organs without fertilisation.
Plant Reproductive Systems
The plant reproductive system is any of the sexual or asexual reproduction processes used by plants. As with mammals, the final consequence of reproduction in plants is the continuation of a particular species, and so the capacity to reproduce is relatively conservative, or subject to only minimal modification, throughout evolution. However, changes have occurred, as demonstrated by a study of plant groupings.
Reproductive Plant Parts
Plant organs include leaves, stalks, roots, flowers, fruits, and seeds, which are all exterior plant structures. Each organ is a collection of tissues that work cooperatively to accomplish a certain job. These structures are classified as sexual reproductive or vegetative. Sexual reproductive components such as flower buds, blooms, fruit, and seeds all generate seeds.
Flowers
Sexual reproduction is the sole purpose of flowers, which are frequently the most visually appealing portion of a plant. The beauty and scent of flowers developed not to satisfy humans, but to attract pollinators (insects or birds), which are necessary for reproduction.
Structure
A flower has a stamen (male flower component) or pistil (female flower component), or both, as well as accessory elements such as sepals, petals, and nectar glands.
Male reproductive organs are stamens. It is composed of a pollen sac (anther) and long filamentous support. This filament secures the anther, allowing the pollen to be dispersed by wind, insects, or birds.
The pistil is the female reproductive organ of a plant. It is frequently shaped like a bowling pin and is positioned in the middle of the flower. A stigma, a style, and an ovary make up the stigma. The stigma is at the top and is attached to the ovary through the style. The ovary carries eggs that are contained within ovules. When an egg is fertilised, it grows into an ovule, which then develops into a seed.
Sepals are tiny, green, leaf-like structures found near the flower’s base. They protect the floral bud. The sepals are collectively referred to as calyx.
Petals are the vibrantly coloured parts of a flower. Petals, like nectar glands, may carry the scent. The petals are collectively referred to as corolla. The number of petals of a flower is frequently used to assist in classifying and identifying plant groups and genera. Dicot flowers often contain four or five sepals, petals, or a combination thereof. These floral portions are often seen in groups of three or multiples of three in monocots.
Process of Seed Creating
Pollination is the process by which pollen is transferred from an anther to a stigma, either by wind or pollinating insects. Insect, mammal, or bird pollinated species frequently have brilliantly coloured or patterned blooms that carry scent or nectar. Pollinators carry pollen from blossom to bloom while hunting for nectar, either on the same plant or on distinct species. Plants developed an amazing technique to ensure the survival of their species. Wind-pollinated flowers are frequently devoid of conspicuous floral components and nectar, as they do not require pollinators.
Fruit
Structure
Fruit is made up of fertilised, mature ovules (seeds) and the ovary wall, which can be soft, as in an apple, or dry and tough, as in an acorn. The seeds of certain fruits are encased within the ovary (e.g., apples, peaches, oranges, squash and cucumbers). Others have seeds located on the outside of the fruit tissue (e.g., corn and strawberries).
The seeds are the only portion of the fruit that carries DNA from both male and female flowers. The remainder of the fruit is genetically similar to the maternal plant.
Seeds
A seed includes all of the genetic information necessary for a complete plant to mature. It’s broken down into three sections:
- The embryo is a small plant in a dormant condition. When the conditions are good, it will begin to expand.
- The endosperm (and, in certain species, the cotyledons) has an integrated food source (except orchids), which can be composed of proteins, carbohydrates, or lipids.
- The seed coat, a tough outer coating, safeguards the seed against disease and insects. Additionally, it inhibits water from entering the seed and commencing germination prematurely.
Germination
Germination occurs when a latent seed embryo transforms into an active, developing stage. Before any visible indications of germination develop, the seed coat must absorb water. Additionally, it must have an adequate supply of oxygen and a comfortable temperature. Certain species, such as celery, require additional light. Others require incandescence.
Conclusion
Although seeds are the most common method of plant reproduction, several asexual methods are used that are usually enhancements of natural processes, including cutting, grafting, budding, layering, division, and laboratory tissue cloning, as well as sectioning of rhizomes, roots, tubers, bulbs, stolons, and tillers. Asexual propagation is frequently employed to produce cultivars with unique desirable features that do not germinate from seed. Fruit tree propagation is typically accomplished by budding or grafting attractive cultivars (clones) onto stool-propagated rootstocks that are also clones.
In horticulture, a cutting is a branch that has been severed below the internode of a mother plant and then rooted, sometimes with the assistance of a rooting liquid or powder containing hormones. When a complete root system has grown and new leaves begin to emerge, the clone is a self-sufficient plant that is genetically identical to the parent plant.