Botany - Mphil Thesis

Permanent URI for this collectionhttps://kr.cup.edu.in/handle/32116/30

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    Development and characterization of genomic microsatellite markers in Melia azedarach
    (Central University of Punjab, 2014) Thakur, Sapna; Bhardwaj, Pankaj
    Melia azedarach is ecologically imperative species known for its innumerable biological benefits such as antiviral, anthelminthic, antibacterial, etc. In this study, we developed 43 genomic microsatellite markers from (AG)n enriched library and subsequently employed 23 of them for genetic diversity and population structure analysis of Melia azedarach growing in Indian Thar desert. Fourteen populations encompassing 95 genotypes were selected for analysis and we found a moderate level of diversity (Na = 3.211, Ho = 0.558, He = 0.549, P = 94.41%) in them. Gene diversity (h) among population pairs varied from 0.566 to 0.714 with very low overall genetic differentiation (F = 0.021). The highest value of ΔK estimated using STRUCTURE indicated 2 subpopulations (K=2) and admixed cluster occupied maximum area (75.79%) under Bar plot. Genetic distance based UPGMA dendrogram also identified 2 major clusters among 14 Melia azedarach populations. UNJ tree based on genetic dissimilarity clustered genotypes from different population together. No significant correlation between geographical and genetic distance was found in present study (Rxy = 0.261, P = 0.18). Allele frequency distribution under “mode-shift” indicator was normal L-shaped, suggesting populations under study are not experiencing any recent bottleneck. This study laid the foundation for more precise inference about the biogeography and management of M. azedarach in the Indian Thar Desert
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    Development and chacterization of genomic microsatellite markers in rhdodendron arboreum
    (Central University of Punjab, 2014) Choudhary, Shruti; Bhardwaj, Pankaj
    Rhododendron arboreum, a key species inhabiting Indian Himalayas, has ecological and economic importance. Global climate change and anthropogenic activities can pose a threat to the biodiversity richness. Population genetics characteristics are the fundamentals of conservation and management practices. However, no genetic background for the species is presently available. To provide an insight into the population structure of the species, an effective marker resource was developed. A genomic library enriched for microsatellites was constructed using biotin- streptavidin hybridization technique, followed by sequencing of positive clones. With 54% enrichment rate, 41 primers were designed from SSR clones, consisting of perfect or interrupted repeats of AG/CT, AC/GT motifs. 38 loci showed successful amplification on genotypes of three populations with number of alleles ranging from 2 to 14, observed and expected heterozygosity of 0.167 to 0.933 and 0.422 to 0.917, respectively and average polymorphic information content of 0.104 to 0.811. A high gene flow (Nm= 5.436) demonstrated high genetic diversity within the populations. 19 loci displayed significant deviations from Hardy Weinberg equilibrium. Overall no linkage disequilibrium and bottleneck was detected among sampled populations. DARwin and STRUCTURE analysis grouped the populations into two original clusters and admixed genetic stock irrespective of their geographical locations. These novel loci will support further genotyping studies in R. arboreum.