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Africa 
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Genomics and Bionanotechnology
Published in Anil Kumar Anal, Bionanotechnology, 2018
Genome mapping is the process of locating the order of gene and their relative distance on the genome. It provides guidelines for the reconstruction of genome sequence after sequencing. DNA sequencing is a complex process due to which the genome needs to be fragmented before sequencing. The fragmented genome sequences are rearranged in original order using recognizable features. As genome map carries information about genome organization in terms of genes, restriction enzyme sites, and others, genome map is utilized to reconstruct the original genome after sequencing. There are two types of genome mapping that includes genetic mapping and physical mapping. For genetic mapping, commonly used markers are genes with visible phenotype and molecular markers, which is DNA sequence that shows polymorphism. Physical mapping involves direct location of DNA sequence on the chromosome using genome-wide unique DNA sequences, sequence-tagged site (STS), and expressed sequence tag (EST) as markers. Different physical mapping techniques include cytogenetic mapping, fluorescent in situ hybridization (FISH), restriction mapping, STS content mapping, and radiation hybrid mapping (Saraswathy and Ramalingam 2011).
Molecular and phytochemical assessment for some seedy strains of Alamar apricot rootstock under salinity stress
Published in Egyptian Journal of Basic and Applied Sciences, 2019
M. H. Abd El-Aziz, S. Y. Mohamed, Hadeer E. Magwaid
Molecular markers are premium tools for assessing genetic diversity, which help breeders to select important traits support the improving productivity of economic plants. It was shown that molecular marker data are very important for any breeding program to select promising varieties with traits of interest [9]. Markers such as ISSR and SCoT are used efficiently for genetic diversity assessment of plants [10]. Inter-simple sequence repeats (ISSRs), a class of molecular markers involves the use of microsatellite sequences as primers in a polymerase chain reaction to generate multilocus markers, were first described by Zietkiewicz et al. [11], and Kantety et al. [12]. These markers targets genome regions flanked by the simple sequence repeats (SSR or microsatellite sequences). So, they offer great potential for assessing genetic diversity compared to other arbitrary markers like RAPD, since they reveal variation within unique regions of the genome at several loci simultaneously. They exhibit specificity of sequence-tagged-site markers but need no sequence information for primer synthesis featuring the random markers advantages. ISSR-primers can be based on any of the SSR motifs (di-, tri-, tetra- or penta-nucleotides) found at microsatellite loci, giving a wide array of possible amplification products [11]. Having single primer, ISSR sequences can be amplified using Polymerase Chain Reaction (PCR) provided that within the amplifiable size domain. This reaction yields multiple amplification products (Amplicons) that can be used as a dominant multi-locus marker system for genetic diversity study in various organisms. Start Codon Targeted polymorphism (SCoT) is a new molecular marker technique, and not yet used in the apricot diversity studies except for study on native apricots in Southern Xinjiang of China [13]. It is a novel, simple, and reliable gene-targeted marker technique based on the short-conserved region flanking the ATG start codon (initiation codon) in plant genes. This technique uses single 18-mer primers designed to anneal with surrounding regions of the start codon on both DNA strands [14,15]. This technique was described by Collard and Mackill [16], it uses a single primer as a forward and reverse primer, like the RAPD or ISSR technique. Also, SCoT can generate dominant markers caused by sequence variations and co-dominant markers caused by insertions and deletions [17]. SCoT is superior over other dominant DNA marker systems like RAPD and ISSR in higher polymorphism and better marker resolvability [18].