Srivastava, PujaRushali2022-08-282022-08-282021Rushali (2021). Exploiting the Indian dwarf wheat (Triticum sphaerococcum) as an alternate height reducing system (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810186782The present investigation entitled as “Exploiting the Indian dwarf wheat (Triticum sphaerococcum) as an alternate height reducing system” was conducted with the overall goal to exploit the dwarfing genes available in T. sphaerococcum genotypes. The current study involved the morpho-physiological and molecular characterisation of the 31 T. sphaerococcum genotypes along with Sugar-free, Sonamoti and Nanhe Samrat and 11 other standard genotypes/cultivars from diverse eco-geographic regions. All the genotypes were evaluated for plant height and yield related traits. To study the effect of gibberellic acid (GA3) on seedling growth, all the genotypes were grown using cigar roll method in half MS media enriched with four different concentrations of GA3 0.1 μM, 1 μM, and 10 μM and data on 12 different seedling traits was recorded. Most of genotypes showed increase in seedling growth at 10 μM GA3. Based on response indexes for different sets of traits such as roots, shoots and coleoptile lengths, different sets of genotypes giving differential responses to GA3 were selected. Genotypes that showed maximum increase in seedling length may contain GA3 sensitive dwarfing gene and the genotypes which showed no or minimum response to GA3 may contain GA3 insensitive dwarfing gene or absence of dwarfing gene. Based on SSRs molecular diversity analysis among all the genotypes, 45 out of 76 primers showed high polymorphism giving a total of 167 alleles. Clustering analysis was performed on the basis of molecular analysis by preparing a dendrogram using UPGMA method of DARwin version 6.0.16. All the genotypes were clustered into two major clusters and one independent genotype (TS14). First major cluster was divided into three sub-clusters and one independent genotype (TS21). Second major cluster involved 8 genotypes. Based on the plant height data, genotypes of T. sphaerococcum (TS10, TS13, TS16, TS24 and Nanhe Samrat) were selected for genetic segregation study. Genetic inheritance studies were then conducted using F2 populations derived from 10 different crosses which showed different phenotypic ratios including 1:4:6:4:1 and 1:2:1 inferring the segregation of different sets of genes regulating plant height in the genotypes studied. Further genetic studies can be planned to identify the novel dwarfing genes (both sensitive and insensitive to GA3) present in these genotypes.EnglishThesis