Pre-fertilization in Plant: Pistil (Female Reproductive Unit)

Pre-fertilization in Plant: Pistil (Female Reproductive Unit):

Pistil: The pistil is the female reproductive organ of a flower. It consists of three major components: the stigma, style, and ovary.  

Ovule: The ovary of a flower contains an ovule, which develops into a seed after fertilization. It contains the female gametophyte, including the egg cell, which combines with pollen to form a zygote. 

Forms of ovule: There are six types of ovules in a plant, and these types of ovules are based on their shapes. 

Orthotropous ovule:

• An orthotropous ovule is the simplest type of ovule, where the micropyle, chalaza, and funiculus are all aligned in a straight line. The ovule is upright with no bending or curvature, commonly found in gymnosperms and some angiosperms. 

Anatropous ovule:

• An anatropous ovule is the most common type of ovule in flowering plants. It undergoes a 180-degree curvature during development, resulting in the micropyle facing the funiculus, giving it a distinct bent shape.  

Hemi-anatropous ovule:

• A hemi-anatropous ovule shows a partial curvature, about halfway between orthotropous and anatropous ovules. The ovule is bent at a right angle, so the micropyle is positioned sideways relative to the funiculus.

Campylotropous ovule:

• In a campylotropous ovule, there is a distinct curve in the ovule, but it is less pronounced than in anatropous ovules. The micropyle is located near the funiculus, but the ovule has a more curved shape compared to hemi-anatropous ovules.

Amphitropous ovule:

• An amphitropous ovule exhibits a significant curvature, with the ovule almost folded in half. Both the micropyle and chalaza are positioned close to each other due to the bending, and the ovule often appears horseshoe-shaped. 

Circinotropous ovule:

• A circinotropous ovule undergoes a full rotation during its development, often completing a 360-degree twist. As a result, the micropyle initially faces upwards and eventually loops back to align near the funiculus, making this ovule unique in its circular orientation.