Thumbnail Image

Thesis

Browse

20151
Reset filters
Subject: Biotechnology × Author: Jindal, Suruchi × Thesis Type: Ph.D ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Physical and Genetic Mapping of chromosome 2AL of wheat (Triticum aestivum L.)
    (PAU, 2015) Jindal, Suruchi; Singh, Kuldeep
    Among crop plants, hexaploid wheat has one of the largest genome, being 17000 Mbp. The largest genome coupled with polyploidy nature and very high level of repeat sequence makes sequencing of hexaploid wheat very complex. Several studies, coordinated by IWGSC (International Wheat Genome Sequencing Consortium) are in progress with the aim of obtaining and characterizing the wheat genome. The IWGSC has produced a draft sequence of hexaploid wheat genome by sequencing chromosome arms that were isolated from double ditelosomic stocks of Chinese Spring by flow sorting. Under IWGSC, India has the mandate for generating Bacterial Artificial Chromosome based physical map and whole genome sequencing of chromosome 2A and and PAU has been given the responsibility for physical mapping and sample sequencing of chromosome 2AL. BAC library comprising 76,800 clones for the long arm of 2A with an average insert size of 120kb and 16X coverage was generated from DNA of chromosome arms purified by flow cytometry. Using HICF (High Information Content Fingerprinting) we have fingerprinted 76,800 clones in total as group, out of which 20,000 clones were fingerprinted for this thesis. Automated assembly of high quality fingerprints was performed to generate physical map for 2AL using FPC (Fingerprinting Contig) and LTC (Linear Topolgy Contig) software for the generation of Minimum tiling Path (MTP). FPC and LTC generated 2450 comprising 5804 clones and 1204 contigs comprising 7854 clones respectively. Whole genome shotgun sequence for the chromosome 2AL was also generated using Illumina GAII, Hiseq2000 (paired end) and 454 Roche platform. Both the platforms generated combined reads of 4, 50,120,605 for the long arm. De novo hybrid assembly resulted into 425,821 contigs for 2AL covering 63% of arm. Size based markers were generated from assembled chromosome data. SSR mining was done on the assembled data which resulted in identification of more than 3000 usable SSRs for 2AL using MISA tool. About 501 di-, tri-, and tetra- nucleotide SSR markers were identified, with one marker from each contig for genetic mapping. Insertion Site Based Polymorphism markers (ISBPs) were also predicted from the assembled data using ISBPFINDER.pl. A total of 2, 16,414 ISBPs have been predicted out of which 12,706 can be used as markers and 50 ISBPs were selected randomly for mapping. Parental polymorphism was done on Triticum monococcum and Triticum boeoticum using ABI 3730XL genotyping system and agarose gel system for SSRs and ISBPs respectively. 225 SSR markers and 6 ISBP markers were found to be polymorphic, out of which 95 loci (including SSR and ISBP markers) were used to enrich the genetic map of 2A using the RIL population derived from the cross between Triticum monococcum and Triticum boeoticum and 39 markers were mapped on 2AL while remaining markers mapped on other linkage groups.