Problem 4 - Campbell Biology

Question

Which statement concerning grafting is correct? (A) Stocks and scions refer to twigs of different species. (B) Stocks and scions must come from unrelated species. (C) Stocks provide root systems for grafting. (D) Grafting creates new species.

Step-by-Step Solution

Answer

Stocks provide root systems for grafting.

Step 1: Understand the Terminology

First, identify and understand the terms 'stocks' and 'scions' used in the context of grafting. In horticulture, 'stock' refers to the plant that provides the root system, while 'scion' refers to the plant part, usually a branch, that is grafted onto the stock.

Step 2: Evaluate Statement (A)

Statement (A) says that stocks and scions refer to twigs of different species. This is incorrect because stocks provide the root system and scions are grafted onto them. It is not necessary for them to be from different species; they can be from the same species as well.

Step 3: Evaluate Statement (B)

Statement (B) claims that stocks and scions must come from unrelated species. This is also incorrect because while grafting often involves different species within the same genus, it is not a requirement. They can be related.

Step 4: Evaluate Statement (C)

Statement (C) asserts that stocks provide root systems for grafting. This is correct because the stock is indeed the part of the plant used to provide the root system onto which the scion is grafted.

Step 5: Evaluate Statement (D)

Statement (D) says that grafting creates new species. This is incorrect because grafting does not create a new species; it combines parts of different plants to grow as one.

Key Concepts

Root System

The root system of a plant plays a crucial role in its survival and growth. It serves as the plant's anchor, absorbing water and nutrients from the soil. In grafting, the root system, or 'stock', provides essential support to the plant that is being grafted onto it. By selecting a healthy and robust root system, horticulturists can ensure that the grafted plant has a strong foundation for growth.

• The root system ensures stability for the plant.
• Provides essential nutrients and water.
• Crucial for successful grafting outcomes.

Stock and Scion

In the context of grafting, understanding the terms 'stock' and 'scion' is fundamental. The 'stock' refers to the lower part of the graft combination that provides the root system. It is often chosen for its established root system and viability. The 'scion', on the other hand, is the plant part that is grafted onto the stock, usually a young branch or twig. This part will form the upper part of the graft and is chosen for its desirable traits like fruit quality or flower color.

• Stock is the plant providing the root system.
• Scion is the part grafted onto the stock.
• Both components must be compatible for successful grafting.

Horticulture Techniques

Horticulture involves a variety of techniques to propagate and improve plants, and grafting is one of them. Grafting allows the combination of different plant strengths — such as a strong root system with a high-yielding fruit-bearing scion. Techniques can vary, but generally involve precise cuts and careful joining of the stock and scion. Proper alignment and aftercare are critical for the graft to take and for the plant to grow successfully.

• Essential for plant propagation and improvement.
• Combines desirable traits from two plants.
• Requires precise technique and care.

Plant Species Compatibility

For successful grafting, the stock and scion should be compatible, typically needing to be closely related species or within the same genus. Compatibility ensures that the vascular systems of the stock and scion can integrate, allowing nutrients and water to flow between them. Incompatible grafts often fail because the tissues cannot bond properly. Understanding compatibility helps horticulturists select the best pairs for grafting, resulting in strong and productive plants.

• Compatibility is crucial for graft success.
• Usually involves closely related species.
• Ensures proper nutrient and water flow.