The knowledge of the genetic diversity of barley (Hordeum vulgare) genotypes based on protein polymorphism is very important for breeding programs. The purpose of the current study was to determine the genetic diversity and relationships among ten barley genotypes by using Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) for protein profiles. A total number of 30 bands with molecular weights ranging from 12 to 148 KD were detected. Out of these, five bands were observed monomorphic. Rest of the bands had shown polymorphism to the extent of 83.3% among the test genotypes. The genetic similarity of the ten genotypes tested varied from 0.26 to 1.00 with an average of 0.51. Cluster analysis divided the ten genotypes into two major clusters comprising four subclusters, which was consistent with the systematic classification of barley done in previous studies. The results of this study indicated that the genotypes of barley could effectively be differentiated based on polymorphism, detected between protein patterns. SDS-PAGE presented a higher differentiation power and better repeatability; thus, could be used as a rapid and reliable method for genetic diversity analysis and laid a solid foundation for future barley breeding.

The present study was carried out to conduct drought tolerance in three wheat cultivars including susceptible (Gemmiza7) and tolerant (Sakha93 and Sahel1). Molecular characterization was done by 26 SSR markers located on chromosome7 which was associated with drought tolerance in many previous studies. 26 SSR markers were polymorphic and thus showed 100% polymorphism. The number of alleles per locus varied from 2 to 3 alleles with an average (2.62). The polymorphism information content (PIC) value ranged from 0.34 to 0.59, with a mean of 0.51. The discrimination power (Dp) value ranged between 0.67 and 0.78 with an average of 0.71 per locus and Heterozygosity (He) value varied from 0.44 to 0.67 with an average of 0.59. The genetic relationships estimated by the polymorphism of SSR markers revealed a greater level of genetic variability in wheat cultivars of wide adaptability and applicability. Whereas an average of combined probability value for the SSR markers was 6.15 x 10-16, suggests the capability of the marker system to distinguish identity and purity of wheat cultivars. In addition to the SSR markers revealed various bands that were either absent or present within tolerant cultivars (Sakha93 and Sahel1) which were altogether absent in susceptible cultivar (Gemmiza7). Also, SSRs of diagnostic and curatorial importance were discerned as ‘stand-alone’ molecular descriptors for barcoding the application of DNA sequences of standardized genetic markers for the identification of wheat cultivars. However, the genetic information in this study could provide useful information to address breeding programs and germplasm resource management.

Introduction Bread wheat (Triticum aestivum L.) is annual crop, self-pollinator and contains Genome Hexoploid (AABBDD). Wheat, ranking second among cereals, supplies nutrients to more than one billion of population (Mergoum et al., 2009 and Braun et al., 2010). The demand of wheat is anticipated to increase by 40% in next ten years (FAO, 2015). Arid and semiarid areas adversely affected by drought environment that suffered from reducing more than 50% of yield crops (Jalilvandy & Mehdi, 2013). Plant breeders detected intensively for reliable and rapid method to combat drought problems. So, the researches on wheat to develop or introduce new superior genotypes or varieties that are very valuable (Subhani et al., 2012; Khan et al., 2013; Mahmood et al., 2013 and Aktas, 2016). These genotypes can tolerate serious drought stress without considerable reduction in grain yield. However, Talebi et al. (2009), Pireivatlou et al. (2010) and Koleva & Dimitrova E STIMATION of nine yield-based drought tolerance indices was studied in ten wheat genotypes and identification of best index and best drought tolerant genotype. Nine drought tolerance indices comprising stress tolerance index (STI), tolerance index (TOL), stress susceptibility index (SSI), geometric mean productivity (GMP), mean productivity (MP), harmonic mean (HAM), yield index (YI), yield stability index (YSI) and drought resistance index (DRI) were each estimated based on yield under non-stress (Yp) and stress condition (Ys). The results of the genetic analysis for all drought tolerance indices studied demonstrated that GMP, MP and HAM had less variation between phenotypic coefficients of variability and genotypic coefficient of variability corresponded to high heritability. GMP, MP and HAM were nominated as the best useful indices that looking for drought tolerant genotypes. Also, they had positive correlation with Yp and Ys. The genotypes 1, 6 and 10 were considered drought tolerant while genotypes 3, 4, 5, 7 and 9 as drought susceptible. Genotype 8 was identified as highly drought susceptible. The studied genotypes showed considerable variation in performance and tolerated various drought conditions that could be exploited in further investigation.

The genetic variability and relationships among 5 Egyptian wheat genotypes representing Sakha8, Sakha69, Sakha93, Sids1 and Gemmiza7 were analyzed using 8 random amplified polymorphic DNA (RAPD). A total of 77 loci (73 % polymorphic) in all 5 wheat genotypes was amplified and discriminated all the wheat genotypes. PIC, RP, MI, DP values were evaluated and revealed degree of genetic divergence among the cultivars used. A cluster based on UPGMA (Un-weighted Pair-Group Method with Arithmetic Mean) analysis was used to determine genetic similarities. The five wheat genotypes were divided into two main clusters. Cluster 1 was divided into two groups. In subgroup 1 were included genotype 1 and genotype 2. They seemed very close which might depict sharing of the genetic background among the genotypes. In consequence, the close genetic relationships are entirely alarming and may hinder further plant improvement. Genotype 5 was in subgroup 2. The second cluster was included genotype 3 and genotype 4. The same genotypes were also assessed in field conditions for structural analyses, which were carried out based on six yield components. The dendrogram created was comparatively analyzed with the RAPD dendrogram. This study additionally indicates that RAPD markers are useful for distinguishing and characterizing wheat cultivars. The genetic relatedness among these genotypes could provide useful information for conservation and selection of cross parents in breeding.

The Date Palm (Phoenix dactylifera L), germplasm commonly cultivated in Egypt, shows a wide range of repining periods and fruit quality and is an unexploited resource for breeding programs. The main purpose of this study was to fingerprint 45 date palm genotypes and accessions and to construct a molecular database including the cultivars commonly grown in Egypt. An analysis of thirty three microsatellite simple sequence repeat (SSR) loci out of thirty five markers was performed to define distinct specific alleles across all loci, genetic similarity within cultivars in each region of five different locations and possibility of linking morphological traits with molecular data. In general, the results indicated the possible use of SSR analysis to detect cultivar-specific markers for forty five Date palm cultivars and accessions under investigation that can be used to discriminate among the cultivars and genotypes. The genetic distance among populations compared to each other (Hayani, Samany and Zagholol) which presented at different locations in this study, may or may not correlate with the geographical distance between them in some species, depending on natural and artificial factors involved in shaping the population genetic structure of the species. Based on our findings, it is clear that there is some discordance between the data corresponding to molecular variability and those related to the variability available for breeding purposes (phenotypic variability). However, the use of 33 polymorphic microsatellite markers to study Egyptian date palm germplasm suggested that this is reliable, efficient and effective marker system that can be used for diversity analysis, and subsequently in crop improvement programs.