Multi-trait based index selection for drought stress in foxtail millet genotypes

Foxtail millet is recognized as the second among the small millets after finger millet. It has been documented that foxtail millet exhibits a notable degree of tolerance to drought conditions. Nonetheless, the extent of drought tolerance displayed by foxtail millet varies across different genotypes. Consequently, the selection of genotypes with superior drought tolerance is imperative for prospective breeding initiatives. Hence, the current investigation was conducted to evaluate the response of foxtail millet genotypes for drought stress based on morpho-physiological and root related traits with the aim of identifying drought-tolerant genotypes. A total of twenty-three foxtail millet genotypes were examined at the Pandit Jawaharlal Nehru College of Agriculture and Research Institute (PAJANCOA & RI) located in Karaikal during the Kharif season of 2024. The experimental design included RBD (Randomized Block Design) with two distinct treatments (control and drought condition), each replicated three times. A comprehensive array of morphological, physiological and root-related characteristics was recorded and analysed statistically. Apart from four traits- Canopy Temperature (CTP), Leaf Temperature (LTP), Root Length (RLT) and Root Shoot Ratio (RSR) all the remaining traits exhibited a statistically significant decline in mean performance when subjected to reproductive drought stress in comparison to optimal growth conditions. The Multi-Trait Genotype-Ideotype Distance Index (MGIDI) was employed to assess and identify the genotypes that exhibited optimal performance across twenty traits. The findings indicated that genotype GPUF 18 (G5) emerged as the highest performer across both treatment conditions, showcasing its adaptability and potential for further breeding applications. Additionally, the genotypes were evaluated utilizing nine plant abiotic stress indices, which revealed significant correlations that could facilitate the selection of tolerant genotypes under varying stress scenarios. Genotype IIMR FxM 12 (G3), characterized by a low Average Sum of Rank (ASR), was identified as a drought-tolerant foxtail millet genotype predicated on single-plant yield. This study identified drought-tolerant genotypes to develop drought-resistant foxtail millet.