Gynoecium

Definition Of Gynoecium

The gynoecium is the female part of a flower. It is composed of one or more units called carpels. It forms the ovules and, after fertilisation, the seeds and fruit.

Structure Of The Gynoecium

The structure of the gynoecium varies in different species of plants and forms part of the reproductive part of the flower.

Parts Of The Gynoecium

There are three main parts: carpels, ovary, style, and stigma.

Carpels: The Basic Units Of The Gynoecium

• Carpels are the basic structural units of the gynoecium.

• Each carpel can hold one or many numbers of ovules.

• The carpels are either free and apocarpous or fused and syncarpous.

Structure And Function Of Ovary

• It is the basal part of a carpel.

• The ovules it has, when fertilised, develop into the seeds.

• It provides protection, and nutrition, and gives a chance for the ovules' development.

Structure And Function Of Style

• It is a slender stalk that connects the ovary.

• It serves as a conduit through which the pollen tubes can access the ovules.

• The length and structure differ in various species.

Structure And Function Of Stigma

• The upper part of the style

• Sticky surface to capture and hold on to pollen

• Facilitates pollen grain germination

Types Of Gynoecium

Gynoecium can be classified based on the number of carpels and their arrangement

Monocarpellary: Single Carpel

• It contains only one carpel

• The simplest form of gynoecium

• Example: Beans, peas

Multicarpellary: Multiple Carpels

• It contains two or more carpels.

• Can either be free or fused.

• Examples include tomatoes and lilies.

Fusion Of Carpels

According to research done by Prof. Mike and Nicolescu, carpels may be in two forms. They may either be free or fused. Then this will affect the appearance and its function in the gynoecium.

Apocarpous

• The Carpels are free

• The carpels are not fused and are separate.

• Each of the carpels develops in separate entities.

• Occurs in flowers such as buttercups.

Syncarpous

• The Carpels are one compound

• The carpels are fused to form one as seen above.

• It plays a very important role in the reproduction process of flowering plants.

Functions Of The Gynoecium

The gynoecium plays a vital role in the reproductive process of flowering plants.

Reproduction

• Formation of ovules that become seeds after fertilisation has taken place.

• Allows for male and female gametes to combine.

Pollination Process

• Pollen is caught by stigma from pollinators or non-living factors.

• Pollens germinate on the stigma and grow down the style into the ovary.

Fertilisation And Seed Formation

• The pollen tube enters the ovule, releasing the sperm cells.

• Fertilisation takes place, and seeds start developing.

• The ovary develops into a fruit, containing the seeds.

Modification Of Gynoecium

The gynoecium modifies its structure according to the position of the ovary and the number of ovules.

According To The Position Of Ovary

The position of the ovary concerning other floral parts distinguishes the gynoecium into three types.

Hypogynous: Ovary Above Other Floral Parts

• The ovary is above the point of attachment of all floral parts.

• Examples are hibiscus and mustard.

Perigynous: Ovary At The Same Level

• The ovary is at the same level as other floral parts.

• Examples include roses and cherries.

Epigynous: Ovary Below Other Floral Parts

• The ovary is situated below the attachment of other floral parts.

• Examples include apples and cucumbers.

Based On The Number Of Ovules

The gynoecium can also differ based on the number of ovules that are present.

Uniovulate: Single Ovule

• Each carpel has only one ovule.

• Examples include mango and wheat.

Pluriovulate: Multiple Ovules

• Each carpel has many ovules.

• Examples include papaya and watermelon.

Gynoecium Development

Development of gynoecium involves initiation and differentiation in the floral meristem, which occurs under genetic pathways.

Initiation And Differentiation In Floral Meristem

• Gynoecium originates from the floral meristem, the mass of undifferentiated cells.

• Specific genes direct the differentiation of such cells into carpels, ovary, style, and stigma.

Genetic Regulation Of Gynoecium Development

• Genes involved in the development and pattern formation of the gynoecium.

• These genes are responsible for mutations that lead to abnormalities in the gynoecium structure.

Gynoecium Among Different Plant Families

Different plant families show differences in the structure and modifications of their gynoecium.

Fabaceae

• Monocarpellary usually

• Ovary generally unilocular with marginal placentation

• Examples are Beans, peas

Solanaceae

• Usually syncarpous, bi-carpellary, or tricarpellary gynoecium

• The ovary is generally bilocular with axile pl.

• Examples include apples, cherries, and strawberries.

Importance Of Gynoecium In Plant Breeding

The gynoecium plays a crucial role in plant breeding and agriculture.

Role In Hybridisation

• Facilitates cross-pollination and hybrid seed production.

• Selection of desirable traits through controlled pollination.

Impact On Fruit And Seed Development

• A properly developed gynoecium ensures top-quality fruit and seed production.

• Genetic manipulation of the gynoecium could bring an enhanced yield along with quality.

Common Problems And Abnormalities

Several anatomical abnormalities pose an effect on the gynoecium, which may lead to a reduction in plant fertility and reproduction.

Anatomical Abnormalities In The Gynoecium

• Developmental defect, fused carpels or misformed ovary.

• Can decrease fertility or cause sterility.

• Can affect plant reproduction.

Effects On Plant Fertility

• Abnormalities interfere with pollen tube growth.

• This may result in poor seed sets and lower agricultural yields.

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