PANKAJ KUMARGILL, KOMAL JEET2023-03-162023-03-162022-11https://krishikosh.egranth.ac.in/handle/1/5810195308ABSTRACT In the present study, twenty-seven accessions of kagzi and ornamental lime were evaluated for morphological (based on IPGRI citrus descriptor), biochemical and molecular characterization (using RAPD, SCoT and SSR markers). Under morphological characterization, significant variation was recorded in all the studied parameters viz. leaf lamina attachment, leaf lamina shape, leaf lamina margins, fruit shape, shape of fruit base, shape of fruit apex and fruit texture, respectively. Likewise, minimal differences were also recorded in kagzi and ornamental lime accessions for biochemical studies i.e. total soluble solids (TSS), titratable acidity and TSS: TA ratio. These findings were further validated and confirmed using PCR-based molecular markers viz., RAPD, SCoT and SSR markers. Analysis of PCR products of 22 RAPD, 16 SCoT and 40 SSR primers showed 115, 74 and 64 amplicons. The polymorphic percentagewere ranged from 33.33% to 100% for RAPD and SCoT markers, while SSR markers showed 50% to 100% polymorphism among the studied accessions. Likewise, polymorphic information content (PIC) was ranged from 0.20 to 0.90 for RAPD markers, 0.41 to 0.99 for SCoT markers and 0.07 to 0.67 for SSR markers, respectively. The analysis of molecular variance (AMOVA) studiesamong 27 accessions of kagzi and ornamental lime proved the significant genetic differencesi.e. for RAPD (PhiPT = 0.267, P = 0.010); for SCoT (PhiPT = 0.351, P = 0.010) and for SSR (PhiPT = 0.107, P = 0.010), respectively. With the help of STRUCTURE software 2.3.4 and structure harvester ΔK was observed at k=2 indicating the genetic admixture between the two studied populations. Thus, the present study showed clear and distinct variation among kagzi and ornamental lime accessions. Therefore, it could be concluded that the use of RAPD, SCoT and SSRmolecular markers are efficient to identify diversity or closeness in genotypes which may contribute to speed up the breeding programs and aid in citrus crop improvementEnglishThesis