Spores helpful for secondary infections in the spread of stem rust of wheat is

Options

A. aeciospores
B. uredospores
C. teleutospores
D. basidiospores

Answer

To answer the question regarding which spores are helpful for secondary infections in the spread of stem rust of wheat, we can follow these steps:

### Step 1: Identify the Causal Organism
The first step is to identify the organism responsible for stem rust of wheat. The causal organism is **Puccinia graminis**.

### Step 2: Understand the Life Cycle
Next, we need to understand the life cycle of Puccinia graminis. This fungus is **heteroecious**, meaning it requires two different hosts to complete its life cycle. The primary host is **wheat**, and the secondary host is **barberry**.

### Step 3: Identify the Types of Spores
Puccinia graminis produces several types of spores during its life cycle. The main types include:
- **Aeciospores**
- **Iridospores**
- **Teliospores**
- **Basidiospores**

### Step 4: Determine the Role of Each Spore Type
- **Aeciospores** are produced on the barberry and can infect wheat.
- **Teliospores** are the resting spores that can survive unfavorable conditions.
- **Basidiospores** are produced on the barberry and are responsible for the infection of wheat.

### Step 5: Answer the Question
Given that the question asks for the spores that are helpful for secondary infections in the spread of stem rust of wheat, the correct answer is **basidiospores**. These spores are responsible for transferring the infection from the barberry plant back to the wheat.

### Final Answer
The spores helpful for secondary infections in the spread of stem rust of wheat are **basidiospores**.

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