DefinePK

Research Objective

To screen existing wheat genotypes for genetic potential and heritability of yield-contributing traits under the agro-climatic conditions of Dera Ismail Khan.

Methodology

The study utilized twenty-five wheat genotypes and two local checks (total 27 genotypes). The experiment was conducted at Gomal University Dera Ismail Khan during the 2019-2020 academic year (Rabi season, sown in November). The design used was Randomized Complete Block Design (RCBD). Data were collected on yield-contributing traits (No. of tillers per plant, spike length, spikelet per spike, No. of grains per plant, spike density, 1000-grains weight, and grain yield per plant) from five randomly selected plants per line. Statistical analysis included Analysis of Variance (ANOVA), calculation of Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV), broad sense heritability ($h^2_{BS}$) using Falconer's formula, and Genetic Advance (GA).

Methodology Flowchart

                        graph TD; A[Select 25 Genotypes + 2 Checks] --> B[Conduct Field TrialRCBD, 2019-2020]; B --> C[Data Collection on Yield Traits]; C --> D[Statistical Analysis: ANOVA, GCV/PCV, $h^2_BS$, GA]; D --> E[Identify High Heritability Traits]; E --> F[Recommend Genotypes G4 & G26 for Breeding]; F --> G[Conclusion on Genetic Potential];                    

Discussion

Significant genetic variability exists across all traits, making selection for improvement possible. Traits like number of grains per spike (93.28%), grain yield (75.90%), and spike length (66.33%) exhibited high heritability, indicating that environmental influence was low and direct selection would be effective. Traits with moderate heritability (tillers per plant, spike density) require combined genetic selection and environmental management. Spikelets per spike showed low heritability (21.27%), suggesting high environmental influence. Genotypes G4, G23, and G24 were identified as potential high-yielding varieties based on grain yield performance.

Key Findings

Analysis of variance showed significant differences ($P < 0.01$) among the 27 wheat genotypes for all traits studied. High GCV and PCV values were recorded for No. of tillers per plant, spike length, spikelet per spike, and No. of grains per plant, suggesting predominance of additive gene action. High broad sense heritability combined with high Genetic Advance as Percent of Mean (GAM) was found for the number of tillers per plant, number of spikelets per spike, and grain yield per plant. Genotypes G4 and G26 were recommended for improvement via breeding procedures. Genotypes G2, G4, G18, G21, G23, and G24 possess highly diverse genetic backgrounds useful for future breeding programs.

Conclusion

The study confirmed significant genetic potential and variability among the tested wheat genotypes for yield-contributing traits in Dera Ismail Khan. Traits with high heritability, particularly grain yield and number of grains per spike, are amenable to effective selection in breeding programs. Genotypes G4 and G26 are specifically recommended for use in future breeding material improvement.

Fact Check

1. The study involved twenty-five wheat genotypes and two local checks, totaling twenty-seven genotypes tested.
2. High broad sense heritability was observed for the number of grains per spike (93.28%).
3. The research experiment was conducted during the 2019-2020 academic year.

Mind Map