Discrimination of Root System Architectural Traits, Morphometric Traits and Identification of Potential Genotypes in Response to Drought and Irrigated Conditions in Pearl Millet (Pennisetum glaucum (L.) R. Br.)

Aims: To identify the potential genotypes and the important traits for drought tolerance based on root system architectural traits and morphometric traits that can be used as a selection criteria in future crop improvement programs.

Study Design: Completely randomized design for root system architectural traits and Randomized block design with two replications for morphometric traits.

Place and Duration of Study: Department of Millets, Tamil Nadu Agricultural University, Coimbatore during Summer 2022.

Methodology: The 33 elite genotypes were raised in polybags with two factors, one is genotype and other is treatment for observing root system architectural traits in completely randomized design. Also these genotypes were raised in the field in randomized block design with two treatments, irrigated and drought at early stage of the crop for observing morphometric traits.

Results: Based on root system architectural traits, the significant traits were network perimeter, network surface area, network length and network volume. Under irrigated and drought condition, high phenotypic coefficient of variation and high genotypic coefficient of variation were observed for single plant yield, high heritability and high genetic advance for days to 50 per cent flowering, plant height, leaf blade length, spike length, 1000 seed weight and single plant yield. Correlation study revealed that all the characters except number of tillers and days to 50 per cent flowering had positive significant correlation with single plant yield. Path analysis showed that spike length had positive direct effect on single plant yield.

Conclusion: The identified traits for drought tolerance were network perimeter, network surface area, network length, network volume, days to 50 per cent flowering, plant height, leaf blade length, spike length, 1000 seed weight and single plant yield. The identified drought tolerant genotypes were Nattu cumbu, ICMB 10444, 86M38 and PT 6752.