Differential response of finger millet accessions to contrasting saline-water levels and irrigation regimes under desert conditions

Abidemi Talabi^1*Nhamo Nhamo^1*Sumitha Thushar¹Prashant Vikram²HIFZUR RAHMAN¹Mohammad Shahid¹Neeru Sood³Malavika Sudheer³Dheeraj Thikkamaneni³Amna Almarri⁴Fatma Alsaffar⁴Deep Galani⁵Moyeez Alam³Sonia Goel¹Rakesh Kumar Singh¹

• ¹International Center for Biosaline Agriculture, Dubai, United Arab Emirates
• ²ICAR - Indian Agricultural Research Institute, New Delhi, India
• ³BITS Pilani - Dubai Campus, Dubai, United Arab Emirates
• ⁴Zayed University, Dubai, United Arab Emirates
• ⁵Junagadh Agricultural University, Junagadh, India

Water salinity and scarcity constitute major limitations to crop production in the arid and semiarid regions. Introduction of nutritious and stress-tolerant underutilized crops is a promising approach for dietary enrichment, cropping systems diversification, remediation of marginal and degraded lands, and building climate resilience. The primary objectives of this study were to investigate the effect of water salinity and managed water-deficit stress on grain and fodder yield, identify multi-traits ideotypes, and validate the stability and genetic gain in finger millet ideotypes over a two-year period. Eighty finger millet accessions were evaluated under fresh water (0dS/m) and two saline irrigation water (6 and 10 dS/m) in Dubai, during the 2020/2021 cropping season. Validation of a selected elite subset was conducted under a combination of optimum, salinity and drought stress regimes (0 dS/m, 6 dS/m, 10 dS/m, and 50% irrigation) during the 2021/2022 cropping season. Initial analysis showed a Grain Yield (GYLD) reduction of 87 % under 10 dS/m saline irrigation water compared with the control and the Genotype-by-Treatment (G × T) interaction revealed highly significant effects for GYLD. Using multi-traits genotype-ideotype distance index (MGIDI), 20 elite accessions were identified demonstrating a remarkable increase in mean GYLD under high saline irrigation water, corresponding to a genetic gain of 167 % over the reference population mean. Validation trials confirmed the success of the selection by showing a non-significant G × T for GYLD and dry fodder yield (DFYLD) across the four validation treatments, alongside a significant increase in heritability (H2) for GYLD from 0.60 to 0.78. Comparative analysis revealed that managed water-deficit stress was the most limiting factor for GYLD in the elite subset, causing an average loss of 42.7 % compared to 20.4 % under high saline water irrigation. However, DFYLD displayed exceptional stability across both saline water and water-deficit stress types. The comparative analysis presented in Venn diagrams, ultimately identified a core group of stable, broadly adapted accessions, including IE 4028 and IE 4570, which are recommended as high-impact parental lines for combined stress tolerance. These findings establish a reliable selection framework for enhancing the climate-resilience of underutilized crops in marginal environments.