Physiological Screening of Foxtail Millet Genotypes for Water-Use Efficiency and Yield under Rainfed Conditions
Abstract
Afield experiment was conducted during kharif 2015 to assess water-use efficiency (WUE) traits and yield potential of foxtail millet (Setaria italica L.) varieties under rainfed conditions. The trial followed a randomized block design with three replications and included nine genotypes Krishnadevaraya, Narasimharaya, Prasad, Sri Lakshmi, SiA 3085, SiA 3156, Suryanandi, SiA 3221 and SiA 3223. Significant genotypic differences were recorded for growth attributes such as plant height, leaf area and dry-matter accumulation at successive growth stages. SiA 3156 attained the greatest plant height, leaf area and leaf-area index at 30 and 60 days after sowing (DAS), while Suryanandi produced the highest dry matter across stages. Water-use efficiency–related traits also varied widely: SiA 3221 expressed the highest specific leaf area (161.2 cm²) and SPAD chlorophyll meter reading (49.4), whereas Narasimharaya maintained the highest relative water content at 30 and 45 DAS. Yield components differed significantly among varieties—Krishnadevaraya produced the maximum tillers per plant (5.44), SiA 3085 registered the greatest test weight (3.20 g)and Suryanandi achieved the highest grain yield (3111 kg ha⁻¹), followed by SiA 3085 (2874 kg ha⁻¹) and Krishnadevaraya (2824 kg ha⁻¹). The lowest grain yield occurred in SiA 3221 (353 kg ha⁻¹). Krishnadevaraya recorded the highest straw yield (6395 kg ha⁻¹), while SiA 3156 showed the greatest harvest index (64.67 %). These findings demonstrate substantial genetic variability for WUE traits and yield, highlighting the potential to identify superior foxtail millet genotypes for rainfed cultivation.
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Introduction
Foxtail millet (Setaria italica L.),one of the world’soldest domesticated cereals, is an important small millet cultivated in semi-arid regions for food and fodder. It is valued for its short duration, nutritional quality, and resilience to environmental stress (Zhao et al., 2023). Despite these advantages, yields remain low in rainfed ecosystems due to erratic rainfall and limited availability of drought-adapted varieties. Improving yield stability under moisture-limited conditions requires understanding genotypic differences ingrowth and physiological traits. Traits such as chlorophyll content, relative water content (RWC), and specific leaf area (SLA) influence photosynthetic efficiency and water-use dynamics (Zhang et al., 2022; Gao et al., 2023). Likewise, dry matter production and harvest index (HI) are important determinants of yield stability under stress (Srivastava et al., 2022).
Identifying varieties with superior combinations of these traits is crucial for breeding drought-tolerant cultivars. This study aimed to evaluate growth, physiological traits, and yield parameters of foxtail millet varieties under rainfed conditions and to identify superior genotypes for cultivation and breeding programs.
Conclusion
The present study under rainfed conditions successfully revealed significant genetic variability among nine foxtail millet genotypes for key growth, physiological, and yield attributes. The findings clearly demonstrate that superior yield performance under moisture stress is not a function of a single trait but a complex interplay of efficient physiological mechanisms and optimal biomass partitioning.
Genotypes such as Suryanandi, SiA 3156, and Krishnadevaraya emerged as top performers, combining high grain yield with desirable physiological traits. Suryanandi excelled in sustained dry matter production, while SiA 3156 achieved the highest harvest index, indicating superior partitioning of assimilates to the grain. Krishnadevaraya maintained high chlorophyll content (SCMR) and tiller production. Crucially, the high yields of these genotypes were associated with physiological adaptations to water stress, including higher relative water content (RWC) and lower specific leaf area (SLA), suggesting better water retention and potentially thicker leaves.
Conversely, genotypes with luxuriant vegetative growth, such as SiA 3223 and SiA 3221, recorded poor grain yield, highlighting the risk of excessive canopy development under water-limited conditions. The progressive decline in soil moisture during the reproductive stage further underscores the importance of selecting for traits that confer resilience during critical growth phases.
In conclusion, this research identifies Suryanandi, SiA 3156, and Krishnadevaraya as promising, drought-adapted genotypes suitable for direct cultivation in rainfed agro-ecosystems. Furthermore, it provides a robust physiological framework for future breeding programs. A selection index focusing on moderate plant stature, high SCMR and RWC, lower SLA, and a high harvest index is recommended to develop high-yielding, water-use efficient foxtail millet varieties for sustainable production in moisture-stress environments.
