الفهرس 
The economic importance of sunflowerOnly 14 pages are availabe for public view
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Abstract
The present study was carried out at the experimental farms and laboratories of Genetics Department, Faculty of Agriculture, Ain Shams University and Department of Plant Genetic Resource (PGR), Environment Division and the Crops Dry Areas (EDCDA), Baloza Station, North Sinai, Desert Research Center (DRC), from 2014 to 2018.
The main findings of this study could be summarized in the following:
1. Eight morphological and yield–related traits were studied in 14 sunflower genotypes. Analysis of variance and Duncan’s new multiple range test revealed significant differences among all the studied traits (p≤ 0.01).
2. Mean values showed significant differences among all studied genotypes, S8 were the tallest plant (193.3 cm), while the genotype S3 recorded the shortest genotype (131.1 cm). S1 and S8 were the highest genotypes in number of leaves/ plant 25.8 and 25.3, while S10 genotype was the lowest one (15.1). The genotype S7 recorded the largest head diameter (14.9 cm), while two genotypes recorded the lowest values S9 and S3 (9.6 and 8.9 cm). The S5 and S7 scored the highest values of stem diameter (6.6 and 6.4 cm), while three genotypes S9, S12 and S14 recorded the lowest value (4.7 cm). S1 genotype was recorded the highest value of head weighted (255.6 g), while S3 genotype was recorded the lowest value (58.3 g). S1 genotype recorded the highest value of seeds weight (116.7 g), while S3 genotype recorded the lowest value (23.3 g). S1 genotype recorded the highest number of seeds/head (532.2), while the S3 and S10 were recorded the lowest values (270.3 and 271.7). S8 genotype recorded the highest 1000 seeds weight (267.6 g), while S12 genotype recorded the lowest value (82.9 g).
3. Six combinations of F-AFLP succeeded in generation of fragments across the 14 genotypes of sunflower with a total of 1007 amplicons. The number of markers generated was 981 amplicons across the 14 genotypes and their polymorphism was 97.42%. The lowest numbers of amplicons generated through six combination of F-AFLP were produced by C3 was 208 fragments with polymorphism percentage 93.96%, while the combination C1 generated 126 fragments and their polymorphism was 100%. Together, the six combinations of F-AFLP developed 178 molecular markers across the 14 genotypes of sunflower. Out of these, 73 molecular markers were associated with morphological and yield-related traits plant height, 1000 seeds weight, number of leaves/ plant and head diameter (19, 16, 11 and 11, respectively), while the lowest number of molecular markers related to morphological and yield component traits were head weight, number of seeds/ head and seeds weight/ plant g (2, 4 and 4, respectively).
4. The AFLP generated bands were analysed using in-silico PCR to verify amplicons produced across the 14 genotypes of sunflower. Out of the total number of 11671amplicons, the combination C1 recorded the highest number of fragments (2882), while the combination C4 recorded the lowest number (601).The combination C6 successfully determined 473315bp in the genome size, while C4 succeeded in covering 94821bp of the genome, meanwhile, C5 revealed 322 genes and C4 identified 100 gene. All genes were distributed over the 17 chromosomes with chromosome 13 recording the highest number of molecular markers related to traits, whereas chromosome 7 recorded the lowest one. 1865440 bp was identified across the six in-silico combination primers with the percentage of the total chromosomal size, being 0.05122%. The percentage of individual chromosome coverage across the whole six combinations in this study were chromosomes number 1, 5, 16 and 9 that recorded the highest percentage of chromosome coverage with the percentage of 10%,8%, 8% and 8%, respectively. Whereas, chromosomes number 11 and 15 showed the minimum percentage (1%).
5. An AMOVA test was based on the AFLP all datasets and the 73 AFLP loci dataset. The percentage of variation due to differences within population slightly decreased from 92 % in AFLP neutral loci to 92 % in AFLP 73 outlier loci. In AFLP-73 loci, the percentage of variation increased among population to10% in comparison with (8%) AFLP all dataset, indicated that the selected outlier’s loci reflect that the genetic variation within the population was more significant than the variation among populations.
6. Four morphological traits number of leaves/plant, plant height, root length, plant dry weight were studied under salt tolerance under greenhouse conditions between control and two salt stress treatment at 4000 and 6000 ppm. The results of reduction ratio revealed that S10 was the most salt sensitive genotype while, S3 genotype was recorded the most salt tolerant according to the results of reduction ration and overall reduction ration.
7. The results of gene expression by Real-Time PCR (qRT PCR) for two genes (CDPKs and P5CS) showed differential regulation between the two contrasting genotypes S3 and S10, indicated that the ability and efficiency of S3 genotype to tolerate salt.
8. The results of KEGG analysis of pathway for these genes indicated their involvement in salinity tolerance of sunflower.