Introduction
A gynoecium, also known as a pistil, is the female reproductive organ of a flower. It is made up of a stigma, a style, and an ovary. A stigma is found at the style’s tip and might have several lobes. It has a hairy appearance and secretes a sweet liquid. During pollination, pollen grains land on the stigma and attach to their surface because of their sticky nature. During pollination, pollen grains land on the stigma and attach to their surface because of their sticky nature. The style is a stalk that runs from the ovary to the stigma. It aids pollen tube entrance into the ovary. An ovary comprises one to several carpels and is located at the base of the gynoecium. An ovary can have one or more chambers, which are referred to as locules. The locules contain a large number of little structures known as ovules, which are joined to the ovary’s walls by minute connections known as the placenta. The ovary matures into a fruit, and the ovules mature into seeds during fruit production.
Types of Gynoecium
A gynoecium can be one of three varieties, depending on the design of a carpel:
- Monocarpous A single carpel makes up a monocarpous or unicarpellate gynoecium. Avocado, peach, and other fruits are examples
- Apocarpous The carpels of an apocarpous or chlorocarbons gynoecium are numerous and differentiated. Strawberry, buttercup, and Michelin are just a few examples
- Syncarpous Multiple and fused carpels make up the syncarpous gynoecium. Tulips, china roses, and other flowers are examples
Gynoecium Structure
The gynoecium is the flower’s innermost whorl, which has three primary components (stigma, style and ovary).
Stigma
It is the highest component of the female reproductive unit of the flower. The stigma is the part of the pistil head that is exposed to the air or the environment. The stigma’s surface can be sticky, hairy, smooth, rough, and so on. It may easily swallow the pollen grains of the male producing system, or androecium, due to its viscous nature.
The pollen grains are attached to the stigma through a platform. As a result, it is critical for pollination. Stigma comes in a variety of morphologies, including simple, lobed, feathery, funnel-shaped, and branching.
The stigma is made up of stigmatic tissues and single-layered elongated papillary cells. The stigmatic papillae, or elongated papillary cells, serve as a receptor for pollen grains. As a result, it accomplishes the following tasks:
- Adherence of pollen
- Pollen grains are recognised.
- Pollen granules germinate
- Fertilization is begun.
- Pollen grains from several plant species are prevented from entering.
The “Transmitting tissue” of Stigma is tissue enriched with an extracellular polysaccharide matrix. The pollen tube grows towards an ovule with the help of the transmitting tissue.
The stigma can be fused, lobed, branching, or free depending on its location. Sessile stigmas are those that are directly attached to the top of the ovary. Sambucus, Berberit, Lotus, and other plants are examples.
In the syncarpous gynoecium, on the other hand, a stigma remains free or detached. Stigma can be lobed, bilobed/bifid (Compositae family), trifid, and other shapes. Some, like begonia species, are branching, while others, like crocus species, are funnel-shaped.
Style
It’s a stalk-like, filamentous structure that connects the stigma with the ovary. When pollen lands on the stigma, it begins to migrate down through the style structure. The ovary, or basal whorl, is the source of a style.
The gynobasic style is derived from the ovary’s central basis. It can also appear at a right angle to an ovary axis. Stylopodium style is a type of blossom that seems somewhat inflated and is found mostly in Umbelliferae family members.
The Euphorbiaceae family’s flowers feature a free and branching style. It functions as a pollen tube transmitting track (made up of transmitting tissues).
Ovary
It is the most important portion of the gynoecium because it contains the female gametes (ovules). If a gynoecium does not have an ovary, it is considered sterile or parthenogenic. To initiate fertilisation, a pollen particle travels down from the style to the ovary and combines with the ovules or megasporangia.
The megasporangia that carry the megaspores are encased and protected by it. Through the placental wall, the ovary also gives nutrients to the growing ovule.
Gynoecium in flower
The gynoecium, or female portions of the flower, consists of one or more pistils, each of which is made up of an ovary with an upright extension, the style, on top of which the stigma, or pollen-receptive surface, lies. Ovules, or prospective seeds, are contained within the ovary. A pistil can be simple, consisting of just one carpel or an ovule-bearing modified leaf, or complicated, consisting of multiple carpels linked together. The perianth, or floral envelope, is composed of sepals and petals. The sepals are typically greenish and resemble shrunken leaves, whereas the petals are usually bright and conspicuous. Tepals are indistinguishable sepals and petals seen in flowers such as lilies and tulips. The male components of the flower, known as the androecium, are what make up the androecium.
The stamens, also known as the androecium or male portions of the flower, are made up of a supporting filament and an anther, which produces pollen.
Conclusion
A gynoecium, also known as a pistil, is the female reproductive organ of a flower. It is made up of a stigma, a style, and an ovary. The style is a stalk that runs from the ovary to the stigma. An ovary comprises one to several carpels and is located at the base of the gynoecium. Stigma It is the highest component of the female reproductive unit of the flower. The stigma is the part of the pistil head that is exposed to the air or the environment. The pollen grains are attached to the stigma through a platform. The ovary, or basal whorl, is the source of a style. The perianth, or floral envelope, is composed of sepals and petals. The stamens, also known as the androecium or male portions of the flower, are made up of a supporting filament and an anther, which produces pollen.