DefinePK

Research Objective

To evaluate chickpea germplasm under field conditions to identify sources of resistance or susceptibility against Fusarium wilt and Ascochyta blight.

Methodology

Field experiment conducted at Pulses Research Sub-Station, Agriculture Research Institute, Tandojam. Thirty chickpea cultivars (24 advanced lines and 6 commercial varieties) were planted in a Randomized Complete Block Design with three replications. No plant protection measures were applied to allow for natural disease pressure. Disease responses were observed and rated using a 1-9 scale at 30, 60, and 90 days after emergence. Disease index was calculated, and 1000-grain weight and grain yield per hectare were measured. Statistical analysis was performed using `Statistix version 8.1` and `Excell`.

Methodology Flowchart

                        graph TD
    A[Plant 30 Chickpea Cultivars] --> B[Apply Natural Disease Pressure];
    B --> C[Observe and Rate Disease Symptoms 1-9 Scale];
    C --> D[Calculate Disease Index];
    D --> E[Measure 1000-Grain Weight];
    E --> F[Measure Grain Yield Kg/ha];
    F --> G[Analyze Data ANOVA, Correlation];
    G --> H[Identify Resistant/Susceptible Genotypes];
    H --> I[Conclude on Germplasm Potential];                    

Discussion

The study highlights the presence of resistant germplasm against Fusarium wilt and Ascochyta blight, which can be utilized in breeding programs. The findings suggest that while some commercial varieties are susceptible, advanced lines show promise for resistance. The positive correlation between disease severity and yield parameters indicates the significant impact of these diseases on chickpea production. The research supports the use of resistant varieties as an efficient disease management strategy.

Key Findings

- Among the 30 cultivars, none were highly resistant or asymptomatic to both diseases, and none were highly susceptible to both.
- For Fusarium wilt, all genotypes except one (L124, which was moderately susceptible) were categorized as resistant. Commercial varieties were generally susceptible.
- For Ascochyta blight, all germplasm exhibited resistant reactions except for L124, which was susceptible. Black gram and Benezir commercial varieties showed resistant reactions.
- Disease severity of both Fusarium wilt and Ascochyta blight increased over time.
- Commercial varieties generally had higher disease indices for Fusarium wilt compared to advanced lines.
- Advanced lines L101, L107, L108, L111, and L116 showed the lowest disease indices for Fusarium wilt.
- L102 had the lowest disease index for Ascochyta blight, while Nut-2018-19 had the highest.
- Significantly maximum 1000-grain weight was recorded in DG-92, L10, and L119.
- Significantly maximum grain yield was produced by L117, L124, NUT (2018-19), and Black gram.
- Disease severity of both diseases was positively correlated with 1000-grain weight and grain yield.

Conclusion

The study successfully identified chickpea germplasm with varying degrees of resistance and susceptibility to Fusarium wilt and Ascochyta blight under field conditions. The availability of resistant sources is crucial for developing disease-resistant cultivars and incorporating them into high-yielding varieties. Disease severity negatively impacts grain yield and quality, emphasizing the importance of resistance breeding.

Fact Check

- Number of cultivars evaluated: 30 (24 advanced lines and 6 commercial varieties). Confirmed in the abstract and methodology.
- Disease rating scale: 1-9. Confirmed in the methodology.
- Maximum 1000-grain weight: Recorded in DG-92, L10, and L119, ranging from 304.3-305.3 g. Confirmed in Key Findings and Results.

Mind Map