**2. Materials and methods**

The material consisted of 84 genotypes of soybean originated from different places of India and abroad. The experiment was laid in augmented design at the Research Farm of Kisan (PG) College, Simbhaoli, Ghaziabad, during *kharif*, season of 2008. In each replication the genotypes were grown in 2 m long rows with spacing of 40cm × 10cm for row to row and plant to plant, respectively. Within a row, seeds were hand dibbled 10 cm apart. Standard package of practices was followed to raise the crop. Ten competitive plants were randomly selected from each treatment in each replication and data were recorded on 3 qualitative characters namely, pod shattering resistance, rust resistance and yellow mosaic disease resistance.

sporulating intensity. Based on the symptoms, pustule density and sporulation intensity grades were given. The genotypes were later grouped into different categories from immune

Screening of Soybean (*Glycine Max* (L.) Merrill) Genotypes for Resistance to Rust, Yellow Mosaic and Pod Shattering

http://dx.doi.org/10.5772/54697

175

**Sl. No. Scale Category**

3. 3 Moderately resistant

4. 5 Moderately susceptible

1. 0 Immune

2. 1 Resistant

5. 7 Susceptible

6. 9 Highly susceptible

84 soybean genotypes grown in natural (field) conditions at Research Farm of Kisan (PG) College, Simbhaoli, Ghaziabad during *kharif*, 2008 were screened. Number of plants showing distinct symptoms in each line was counted 60 days after sowing and per cent disease incidence

The genotypes were later grouped into different categories from immune to highly susceptible

**Scale Description Category**

1 1% or less plants exhibiting symptoms resistant

7 21 to 50% plants exhibiting symptoms susceptible

3 1 to 10% plants exhibiting symptoms moderately resistant

5 11 to 20% plants exhibiting symptoms moderately susceptible

9 51% or more plants exhibiting symptoms highly susceptible

0 No symptoms of plants Immune

to highly susceptible. The scale (0-9) used was as follows:

**2.3. Screening for yellow mosaic disease resistance**

was calculated by using the following formula:

Number of plants infected in a row

Total number of plants in a row

Per cent Disease Incidence (PDI) = x 100

[7]. The scale used was as follows (0-9):

### **2.1. Screening for pod shattering resistance**

The pod shattering resistance was recorded at physiological maturity of the pod. The screening was done under laboratory condition by following the methodology adopted by IITA [4]. The results were recorded as percentage of pod shattering. IITA method of calculating pod shattering under lab conditions:

A sample of 25 pods were collected and kept in oven at 40°C for 7 days.

On the 7th day the number of shattered pods were counted and expressed in percentage as below,

Number of pods shattered

Pod shattering percentage (%) = x 100

Total number of pods

The genotypes were classified into different categories based on their reaction to pod shatter‐ ing. The scoring rate was followed according to method adopted by IITA.


#### **2.2. Screening for rust resistance**

The scoring for rust was done just after initiation of flowering and before pod formation. The observations were taken on lower, middle and upper leaves for density of pustule and sporulating intensity. Based on the symptoms, pustule density and sporulation intensity grades were given. The genotypes were later grouped into different categories from immune to highly susceptible. The scale (0-9) used was as follows:


#### **2.3. Screening for yellow mosaic disease resistance**

84 soybean genotypes grown in natural (field) conditions at Research Farm of Kisan (PG) College, Simbhaoli, Ghaziabad during *kharif*, 2008 were screened. Number of plants showing distinct symptoms in each line was counted 60 days after sowing and per cent disease incidence was calculated by using the following formula:

Number of plants infected in a row

**2. Materials and methods**

174 Soybean - Pest Resistance

**2.1. Screening for pod shattering resistance**

shattering under lab conditions:

Number of pods shattered

Total number of pods

Pod shattering percentage (%) = x 100

**2.2. Screening for rust resistance**

below,

The material consisted of 84 genotypes of soybean originated from different places of India and abroad. The experiment was laid in augmented design at the Research Farm of Kisan (PG) College, Simbhaoli, Ghaziabad, during *kharif*, season of 2008. In each replication the genotypes were grown in 2 m long rows with spacing of 40cm × 10cm for row to row and plant to plant, respectively. Within a row, seeds were hand dibbled 10 cm apart. Standard package of practices was followed to raise the crop. Ten competitive plants were randomly selected from each treatment in each replication and data were recorded on 3 qualitative characters namely, pod

The pod shattering resistance was recorded at physiological maturity of the pod. The screening was done under laboratory condition by following the methodology adopted by IITA [4]. The results were recorded as percentage of pod shattering. IITA method of calculating pod

On the 7th day the number of shattered pods were counted and expressed in percentage as

The genotypes were classified into different categories based on their reaction to pod shatter‐

**Sl.No Category Resistant reaction**

1. No pod shattering Shattering resistant

2. <25% pod shattering Shattering tolerant

4. 51-75% pod shattering Highly shattering

5. >75% pod shattering very highly shattering

The scoring for rust was done just after initiation of flowering and before pod formation. The observations were taken on lower, middle and upper leaves for density of pustule and

3. 25-50% pod shattering Moderately shattering

shattering resistance, rust resistance and yellow mosaic disease resistance.

A sample of 25 pods were collected and kept in oven at 40°C for 7 days.

ing. The scoring rate was followed according to method adopted by IITA.

Per cent Disease Incidence (PDI) = x 100

Total number of plants in a row

The genotypes were later grouped into different categories from immune to highly susceptible [7]. The scale used was as follows (0-9):

