Evaluation of finger millet (eleusine coracana l.) Genotypes for drought tolerance using morpho-physiological and root traits

Abstract

Water one of the most limiting factor of crop production under drought endemic environments. Water stress affects the morphology and the physiological metabolism of the plant. Finger millet (Eleusine coracana L.) is one of the crop species with resilience to various adverse climate change effects and with high nutritional value. However, its production and yield over the years have declined due to its low preference in favour of modern cereals, drought stress and limited availability of improved varieties. This study was conducted to evaluate in finger millet genotypes for drought tolerance based on morpho-physiological traits. In the first experiment, twenty-four finger millet lines were evaluated alongside a check P224 under field conditions. The experiment was laid in a 5 × 5 triple Lattice design in three replications at two locations for one season. In the second experiment, twenty-four finger millet lines and one commercial check P224 were screened for root-shoot morphological features in polyvinyl chloride pipes under rain out shelter (ROS) conditions in randomized complete block design (RCBD) with three replications. In the third experiment, nine elite finger millet lines including a check P224 selected from first and second experiments based on good root-shoot features, morpho-physiological traits and high yield were evaluated. A split plot design in RCBD was used with water regime as the main plot and the lines as the sub-plot under ROS. Results from experiment one revealed significant (P<0.05) difference among the genotypes, locations and genotype-by-location interactions for morphological, physiological and agronomic traits evaluated. Advanced lines ICFX1420314-2-1-1-1, KNE 814 × Ex Alupe (P) P8-1-1-1-1 and ICFX1420415-3-1-1-2 were outstanding for drought tolerance as they displayed low evapotranspiration rate, high water use efficiency, increased root growth and high grain yield. In experiment two, three lines, ICFX1420431-3-3-1, ICFX1420314-2-1-1-1 and ICFX1420396-5-5-1-1 were identified to have deep rooting system, increased number of root hairs, high root density and root to shoot ratio. Experiment 3 further confirmed the performance of the top nine ranked finger millet lines from experiments 1 and 2 based on agronomic, morpho-physiological and root traits, and high grain yield. In this experiment, morpho-physiological and root traits such as increased root growth, shoot dry weight, root dry weight and grain were identified as parameters that are associated with water use efficiency among finger millet lines studied. In summary, this study identified two elite lines ICFX1420314-2-1-1-1 and ICFX1420431-3-3-1, which can serve as promising parental stock for breeding programmes aimed at improvement of drought tolerance for increased finger millet production in semiarid areas. These lines are also potential candidates for formal release to farmers for commercialization.