RAJA RAJESWARI, VPRANUSHA, P2019-05-022019-05-022018http://krishikosh.egranth.ac.in/handle/1/5810101656D5704The present investigation was carried out in the Indian Institute of Millet Research, Hyderabad to evaluate “Physiological, Biochemical and Molecular Characterization of Finger millet (Eleusine coracana L. Gaertn.) Genotypes for Drought Tolerance”. A field study was conducted with thirty finger millet genotypes, evaluated for drought tolerance in terms of higher physiological efficiency, drought tolerance capabilities and yield along with grain quality traits. The field experiment was conducted during Kharif, 2015 and Kharif, 2016. Field experiment was laid out in Randomized Block Design, replicated thrice and imposed moisture stress from panicle initiation to grain filling stage under rainout shelter during both years of experimentation. During this period morphological characters like plant height, leaf area, total dry matter, physiological parameters, SCMR, relative water content (RWC), chlorophyll stability index (CSI), gas exchange parameters were recorded periodically and yield related parameters were recorded at harvest. Under imposed moisture stress conditions morpho-physiological traits are significantly reduced compared to control, whereas proline (osmoregulant), super oxide dismutase and catalase (antioxidant enzymes) were increased. xvii The genotypes, GE-1013, GE-224, GE-1034 and GE-1028 maintained optimum leaf area, high dry matter, CGR, LAI and LAD compared to other entries and these genotypes also recorded high photosynthetic rate and WUE traits i.e moderate SLA and high SCMR, CSI, high proline accumulation and SOD enzyme activity and higher grain yield, which denotes the efficiency of these genotypes in conserving water as well as maintaining osmoregulation and better performance under moisture stress condition. Whereas GE-5112 and GE 156, GE-4004 and GE-390 recorded lower physiological attributes along with lower yield attributes denoting their susceptibility for drought. Genetic diversity studies with a set of 25 SSR markers revealed presence of variability among 30 finger millet genotypes. The number of alleles ranged from 1 to 7 with an average of 1.64 alleles. The mean values of observed heterozygosity and expected heterozygosity were 0.04 and 0.55. The average polymorphism information content was 0.07 in the present study. The 30 genotypes of finger millet were grouped into 6 clusters by UPGMA method, irrespective of geographical diversity, indicating no parallelism between geographic and genetic diversity. Clusters I, III and V formed solitary clusters revealed that presence of diversity for various characters among these genotypes. The genetic divergence analysis based on physiological attributes helps in providing valuable information in choosing the parents for hybridization for achieving higher yield. The variability existing in the finger millet genotypes provide opportunities for breeders to select specific donors for genetic improvement. The present study revealed that there is a sufficient genotypic variability among thirty finger millet genotypes for growth, drought tolerance, yield and its attributes. The genotypes GE-1034, GE-639 and GE-224, GE-1013 and GE-1028 were identified to be moisture stress tolerant genotypes in terms of physiological efficiency, osmotic regulation, yield and yield components. These genotypes can be used as donor source for crop improvement of drought tolerant finger millet genotypes through conventional or molecular breeding.en-USnullThesis