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ThesisItem Open Access Evaluation of Elymus semicostatus germplasm from lahaul valley as potential donor for wheat improvement(Punjab Agricultural University, Ludhiana, 2020) Antul Kumar; Sharma, RajniThe present investigation entitled “Evaluation of Elymus semicostatus germplasm from Lahaul valley as potential donor for wheat improvement’’ was carried out to evaluate the in depth botanical characterization, their physiological responses in different water environments and hybridization attempts to mobilize the useful traits into wheat. The plant material was collected from Lahaul valley (Lahaul-Spiti, HP) and its adjoining regions. The field experiments were conducted at the research farm of Wheat section, Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana. The E. semicostatus showed morphological resemblance with three other members of the genus Elymus viz: E. longiaristatus, E. repens and E. dahuricus. Forty distinguishing characters were marked for each species. The E. semicostatus showed morphological adaptation for drought tolerance such as dense pubescence, awn length and colour, leaf waxiness and pigmentation on other plant parts. The germplasm set was narrowed down to 34 accessions on the basis of their intra-specific variation during field evaluation. Selected 34 accessions set was evaluated for drought tolerance traits under field conditions. Vernalization treatment for 4-6 weeks at 4-8˚C and 8hr photoperiod was provided to germinated seedlings in December and January for about 6-7 hours to synchronize flowering with hexaploid wheats. The drought conditions were created by withholding irrigation (rainfed), regular recommended irrigation and restricted irrigation (1-2 times after transplantation). The morpho-physiological traits such as plant height, flowering days, spike length, leaf area, tiller numbers, chlorophyll contents at different stages and relative water content were observed at anthesis. For morpho-physiological parameters, the NBPAU28 showed maximum plant height (133cm), spike length (25.67 cm), tiller number (33.17) and leaf area (30.32cm). The accessions NBPAU7, NBPAU13, NBPAU14 and NBPAU28 were best for plant height, spike length, leaf area, whereas NBPAU1, NBPAU6, NBPAU15 and NBPAU27 performed well under drought conditions. The chlorophyll content was significantly increased during anthesis in all accessions and then declined, but it maintains low chlorophyll content upto harvesting stage. In an attempt to cross the species with hexaploid wheat, embryo rescue was attempted. A total of 991 caryopses were obtained from the crosses of three consecutive seasons from 2017 to 2018. Only 20 hybrid plants could be established on account of the desiccating conditions at PAU, which probably contributed to low survival rate. The surviving hybrid plants never reached booting stage at PAU, Ludhiana. The E. semicostatus can be a potential donor for the drought tolerance traits and more detailed studies on overcoming pre and post fertilization barriers need to be done for introgressing useful traits into wheat cultivars for wheat improvement.
