Gahukar, Dr. S. J.KHARADE, SHUTIJA, JAYDEEP2021-12-072021-12-072022-01-11KHARADE, SHUTIJA JAYDEEP. (2020). Biochemical characterization of wheat lines under water stress condition. Biotechnology Centre, Department of Agricultural Botany. Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. M. Sc. 2020. Print. xiii, 94p. (Unpublished)https://krishikosh.egranth.ac.in/handle/1/5810178762An experiment conducted during the year 2019-20 at Department of Biotechnology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Dist. Akola (Maharashtra). In this experiment the investigation was carried out to study the effect of water stress on different wheat lines. Wheat lines were subjected to and in vitro as well as in vivo experiment to analyze effect of drought. Osmotic stress and drought stress showed adverse consequences on physiological, morphological and biochemical parameters that were studied. Proline and relative water content were found to have positive correlation with yield under water stress condition.Drought is multidimensional in nature affecting plant at different level of organization. Under drought conditions, crops close their stomata to limit evaporative water loss, thus reducing carbon uptake by photosynthesis and decreasing yields. Plants sustain water deficit by drought escape, drought avoidance or drought tolerance which all contribute to resistance. Plants endure drought through osmotic alteration, stomatal resistance, improved water uptake by making changes in their metabolism. These traits can be useful in selecting drought tolerant cultivars for water stressed areas. The present study was planned assaying water stress tolerance in wheat genotypes. In this study various morphological, physiological and biochemical observations were recorded. An in vitro study was conducted in which drought stress was artificially created using various concentrations of PEG-6000 (0 %, 10 % and 15%) in a completely randomized block design. Various physiological parameters were recorded. Similarly, an in vivo study was conducted on field where wheat genotypes were grown at different irrigation levels, in control (six irrigation) and water stressed (three irrigation) condition in a randomized block design. These were then evaluated for various physiological, morphological and biochemical parameters. In the in vitro study, the physiological studies showed that germination percentage, shoot-root length, seedling vigour index, relative water content and chlorophyll content decreased with increasing osmotic stress. Osmotic stress showed negative effect on all the studied parameters. In the in vivo study, analysis showed that all the morphological parameters i.e. plant height, tillers per plant, spike length, grains per spike, 1000 grain weight, yield per plant decreased in water stressed condition, while days to 50% flowering increased in water stressed condition. In physiological analysis, relative water content and chlorophyll content decreased in water stress condition. Similarly, in biochemical analysis it was observed that protein content has inverse relation with water stress while proline content and ascorbate peroxidase activity has direct relationship with increasing water stress. Genotypes AKAW-3717, AKAW-4842 and AKAW- 4924 were observed to be superior cultivars for low rainfall areas with possibility of drought spells as they performed well in both in vitro and in vivo studies. AKAW-2862-1 and AKAW-4925 showed a consistently poor performance in both the studies and found to be drought susceptible. It is thus concluded that water stress levels had extensive effect on germination and seedling growth. Morphological, biochemical, physiological analysis discovered that adequate difference for drought tolerance existed in the tested genotypes. AKAW-3717, AKAW-4842 and AKAW- 4924 may prove a promising parent material for breeding drought tolerant wheat cultivars and can be considered better genotypes for low rainfall or drought prone areas. Correlation study showed that relative water content and proline content has significant positive association with grain yield and thus these traits can be used as a selection criterion for such drought environment for further improvement.EnglishThesis