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Genus Medicago belonged to family Fabaceae is one of the most important forage legumes. Annual species of this genus are indigenous to Mediterranean region and used for prevention of soil erosion, green manure and forage. In this research, genetic variability and classification of 14 annual medicago truncatula genotypes using ISSR markers was done. 9 out of 15 ISSR primers which possessed suitable polymorphism and amplification were used for fingerprinting of studied genotypes. Totally, 71 bands were amplified via ISSR primers which 11 bands were monomorphic and 60 bands were polymorphic across genotypes. Based on Jaccard similarity coefficient, minimum similarity (0.25) was seen between TN8.3 (Tunisia) and TN6.18 (Tunisia) and maximum similarity (0.82) was seen between TN8.3 (Tunisia) and SA28064 (Cyprus). Population structure analysis using STRUCTURE software subdivided them into 9 subpopulation. In this study, maximum admixture was occurred in TN1.21 (Tunisia), A10 (Australia), F83005-5 (France), SA22322 (Syria), A20 (Australia), and DZA315-16 (Algeria) genotypes. Results revealed that annual self-pollinated M. truncatula had noticeable genetic variation which Is accurately detectable using ISSR molecular markers

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Nitrate concentration of the soil, at the start of growing season, is high due to minerali-zation of soil organic N during the Fall and the addition of N fertilizers. It may be useful to exploit this N form as much as possible. Therefore, the nitrate uptake, assimilation and dry matter production of several wheat cultivars were examined in a series of experiments using a hydroponic culture system. Seedlings were grown at two rates of nitrates (0 and 1.0 mM) and the experiments lasted for 26 days. Significant genetic variation in the growth and nitrate uptake were observed. The Atila and Yavarous cultivars consistently produced large seedlings absorbing higher quantities of nitrate from the nutrient solution, compared to the Falat, Star and Seri 11 cultivars which produced smaller seedling and took up lower amounts of nitrate. However, apart from seedling vigor, there was evidence that some cultivars were more efficient physiologically in assimilating nitrate. For compa-rable amounts of nitrate taken up from solution, total dry matter production in this group of cultivars was considerably greater than others. Results of this work revealed that ge-netic differences among wheat cultivars affect nitrate uptake, which in turn indicated the influence of plant status and in particular root system on the potential of nitrate uptake.

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Retrotransposons (RTNs) constitute informative molecular markers for plant species because of their ability to integrate into a multitude of loci throughout the genome and thereby generate insertional polymorphisms between individuals. In the present study, RTN-based molecular markers, IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism), were applied to study RTN integration events and genetic diversity in 100 melon genotypes (88 genotypes from 11 populations, three inbred lines, and 9 hybrids). A total of 94 and 262 loci were amplified using 5 IRAP and 15 REMAP primers, respectively. The percentage of polymorphic loci (PPL) in populations ranged from 39% (Zivari Shahrood) to 48% (Shadegani E). The Mantel test between IRAP and REMAP cophenetic matrices evidenced no significant correlation (r= 0.29). IRAP+REMAP-based cluster analysis using UPGMA algorithm and Dice similarity coefficient depicted 6 groups among 100 melon genotypes. AMOVA revealed the higher level of genetic variation within populations (67%) compared to among populations (33%). The mean Fst values of all groups, except for group VI, were more than 0.20, demonstrating differentiation among the populations and genetic structure of the studied melon collection. 

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Designing breeding programs for winter rapeseed (Brassica napus L.) cultivars with improved seed and oil yields requires information about the genetic variability of traits. In this study, 28 winter rapeseed cultivars were evaluated for genetic variation and relationships between 11 agro-morphological characters during 2010 and 2011. Cultivars and cultivar × year interaction showed significant variation for all studied traits. Genotypic coefficients of variation indicated that yield, number of branches per plant, and plant height had the highest variation. Broad sense heritability estimates ranged from 6% to 87% for seed yield and pod length, respectively. Positive correlation was found between seed yield with number of pods per plant, number of branches per plant, days to flowering, and days to ripening. The result of factor analysis showed three independent factors that explained 71% of the total variability, which were named ‘productivity’, ‘phenology and oil’, and ‘pod length’, respectively. According to the first factor, RGS003, Opera, and Hayola were identified as high seed yielding cultivars. Based on all three factors, Lilian, Licord, and Ella were identified as the best cultivars concerning seed yield and oil content. 

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The use of diversity implies knowing characteristics and traits of interest in genetic resources. In forages, the ability to produce seeds is essential to the persistence of cultivars in livestock systems. To study the floral variability and seed yield, 17 genotypes of Chloris gayana Kunth and 14 genotypes of Cenchrus ciliaris L. were evaluated. These genotypes were characterized considering floral morphology and total seed yield parameters. A randomized complete block design with four replications was used. In C. gayana, accessions 7757, 6631, 981 and 7757 presented the highest (P< 0.05) Number of Inflorescences per Plant (NIP, 26.43), number of Spikes per Inflorescence (S/I, 10.73), Weight of Thousand Seeds (WTS, 0.52 g) and Total Seed Production (TSP, 235.69 kg ha^-1), respectively. In C. ciliaris, accessions 15687 (28.67) and 1098 (24.33) presented the highest values (P< 0.05) for NIP. Accessions 777 (151.33) and 6642 (150.67) had the highest (P< 0.05) Number of Seeds by Inflorescences (NSI) and genotypes 6652 (0.238 g), 15687 (0.207 g), 16660 (0.215 g) had the highest (P< 0.05) Weight of one Hundred Seeds (WHS). Finally, accessions 6652 (210.93) and 1098 (188.55) had the highest (P< 0.05) TSP. The genotypes of C. gayana and C. ciliaris indicated an important morphology variation. Likewise, higher seed production, which is associated with genetic variability, can be an attribute to be considered during the selection of materials in forage breeding programs, as a complement to traditional evaluation characteristics.