Browsing by Author "S Adawy, Sami"

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    CONSTRUCTION OF GENETIC LINKAGE MAP AND QTL ANALYSIS OF NET BLOTCH RESISTANCE IN BARLEY
    (IJABR, 2013) S Adawy, Sami; Diab, Ayman A; Sayed, AI; D Ibrahim, Shafik; I El-Morsy, Shafik; M Saker, Mahmod
    Net blotch, caused by Pyrenophora teres f. teres, is one of the most devastating diseases causing significant losses in barley yield and quality. In the present investigation, two barley verities “AT4” (net blotch resistant) and “Femina” (net blotch susceptible) were used to develop a segregating F2 population. Linkage analysis and map construction were performed using Map Manager. The constructed genetic linkage map consisted of 85 markers including 45 AFLP , 11 SSR, 6 CAPS, 5 SCoT, 3 STS and 6 NBL. Linkage groups were assigned to individual barley chromosomes using the published map locations of the SSR markers as reference point. The produced map showed 7 linkage groups with 85 markers covered a total length of 1644.8 cM. The average length of linkage groups ranged from 77.7 to 739.4. Single point analysis was used to identify the genomic regions associated with net blotch resistance in barley. A total of 14 QTL with a significance ranging from 0.01% to 5% were identified on 4 linkage groups (2, 4, 5 and 6). The most significant QTL was found on chromosome 6H. This QTL presents a promising opportunity for the strategic improvement of barley resistance to net blotch using marker assisted selection.
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    Construction of Genetic Linkage Map Showing Chromosomal Regions Associated with Some Agronomic Traits in Cotton
    (ournal of Applied Sciences Research, 2008) S Adawy, Sami; Diab, Ayman A p; AM Atia, Mohamed; HA Hussein, Ebtissam
    Cotton is the world’s leading natural fiber and second most important oilseed crop and has been a focus of genetic, systematic and breeding research. The genetic and physiological bases of some important agronomic traits in cotton were investigated by QTL mapping through constructing of genetic map with chromosomal assignment. A segregating F2 population derived from an interspecific cross (G. barbadense x G. hirsutum) between two genotypes, cvs. “Giza 83” and “Deltapine” was used in this study. Different molecular markers including SSR, EST, EST-SSR, AFLP and RAPD were employed to identify markers that reveal differences between the parents. In total 42 new markers were merged with 140 previously mapped markers to produce a new map with 182 loci covering a total length of 2370.5 cM. Among these new markers, some of them were used to assign chromosomes to the produced 26 linkage groups. The LG2, LG3, LG11 and LG26 were assigned to chromosomes 1, 6, 5 and 20 respectively. Single point analysis was used to identify genomic regions controlling traits for plant height, number of nodes at flowering time, bolling date, days to flowering and number of bolls. In total 40 significant QTL were identified for the five traits on 11 linkage groups (1, 2, 3, 4, 5, 10, 11, 12, 18, 19 and 23). This work represents an improvement of the previously constructed genetic map in addition to chromosomal assignment and detection of new significant QTL for the five traits in Egyptian cotton. The Significant QTLs detected in this study can be employed in marker assisted selection for molecular breeding programs aiming at developing cotton cultivars with improved agronomic traits