Kultur Jaringan dan Sel Tumbuhan : Hasil Kultur dan Pengamatan (Materi 3, Part 3A)

Summary

This video explains the process of plant tissue culture, focusing on the growth and observation of cultured explants. The explant, isolated from plant material, may undergo various changes, including the formation of callus or the direct growth of shoots. The video covers how to observe these developments, including monitoring the formation of callus, shoots, and potential issues like browning or contamination. It also explains the techniques for measuring growth and documenting visual changes to assess the health and progress of the cultures, guiding viewers on how to manage and analyze their tissue cultures effectively.

Takeaways

• 😀 Explants are isolated plant tissues placed in culture media for tissue culture, and their growth is closely monitored for changes.
• 😀 After one or two days, explants may either show signs of death (losing green color, turning transparent or brown) or begin developing new shoots.
• 😀 Direct organogenesis occurs when new shoots form directly from the explant tissue, while indirect organogenesis involves callus formation first, followed by shoot growth.
• 😀 Callus is an undifferentiated mass of cells that forms from damaged explant tissue, which can then differentiate into new shoots.
• 😀 Soft callus is ideal for propagation, especially in liquid media, while compact callus grows more slowly and produces fewer shoots.
• 😀 Browning or blackening of tissue, often a sign of tissue death or contamination, prevents further growth of the culture.
• 😀 Contamination by bacteria or fungi can compromise the culture, and if the culture is fully contaminated, it must be discarded.
• 😀 If part of the explant remains sterile after contamination, it can be salvaged by transferring it to a new sterile medium.
• 😀 Monitoring the culture involves measuring shoot height and recording the number of shoots at regular intervals (weekly).
• 😀 When observing callus growth, the size (diameter and height) is measured to assess the rate of growth.
• 😀 Regular observation and data collection, including visual changes and growth measurements, are crucial for understanding the development of the culture over time.

Q & A

What is an explant in plant tissue culture?

An explant is the isolated tissue or plant part that is taken from a plant for the purpose of culturing in vitro. It is placed in a culture medium to grow and develop into new plants.

What happens to the explant after being cultured in a medium?

After being cultured, the explant may undergo changes such as swelling or color loss, indicating stress or death of the tissue. Eventually, it may either grow directly into shoots (organogenesis) or first form a callus, from which shoots can later emerge.

What is the difference between direct and indirect organogenesis in tissue culture?

Direct organogenesis occurs when shoots form directly from the explant tissue, while indirect organogenesis involves the formation of a callus first, which later develops into shoots.

What is a callus in plant tissue culture?

A callus is an unorganized mass of undifferentiated plant cells that form when the explant tissue is wounded. It can develop into new shoots or other plant structures under the right conditions.

What is the difference between soft and compact callus?

A soft callus is a loose, friable mass of cells that is easy to manipulate and is often preferred for growing in liquid culture media. A compact callus, on the other hand, is denser and harder, typically requiring more time and effort to form shoots.

What are some common problems that can occur during plant tissue culture?

Common issues include browning or blackening of the tissue, which indicates tissue death or poor growth, and contamination by bacteria or fungi, which can spoil the entire culture.

How can contamination in a tissue culture be handled?

If contamination occurs, it may be necessary to discard the entire culture. However, if only part of the tissue is contaminated, the unaffected explants can be transferred to a new sterile medium to try to save them.

How do you monitor the growth of shoots in tissue culture?

The growth of shoots is monitored by counting the number of shoots per explant, measuring their height using an external ruler, and observing any visual changes in color or texture over time.

How is the growth of a callus measured?

The growth of a callus is measured by observing its expansion in both width and height. The largest dimensions of the callus are typically recorded, just as with shoot height measurement.

Why is it important to track visual and quantitative changes in tissue culture?

Tracking both visual changes (such as color and texture) and quantitative changes (like the number of shoots or callus size) helps assess the health and progress of the culture, guiding decisions for subculturing or other interventions.