Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted ...Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted 70% on wheat variety Mexipak in Syria, and recurrent infection in 2010, caused by a virulent race called Yr27, caused a considerable loss in the production of bread wheat cultivars （Cham 8, Cham 6 particularly） amounted 90%. Recently, 15 races of yellow rust had been addressed in Syria for seasons 2010-2014; 159E256, 166E254, 166E256, 255 E112, 0 E0, 64 E 6, 230 El50, 0 E 18, 198 El30, 166 El50, 102 El60, 128 E0, 126 El50, 214E150, and 6E16. The race 6E16 was the most frequent during the two seasons, while the race 255El12 was the most virulent, followed by the race 230E222 and the race 0E0 was the weakest one. This study revealed the presence of fourteen newly observed races in Syria. Molecular Variance Analysis of Molecular Variance （AMOVA） of 55 yellow rust Puccinia striiformis f.sp tritici isolates examined by Amplify Fragment Length Polymorphism （AFLP） revealed high genetic variation within population, and the dimensional scale analysis （MSD） and tree diagram showed that the Syrian yellow rust isolates were clustered in three groups： the first group contained isolates derived from durum wheat, the second one contained bread wheat isolates, but the third was made of isolates derived from both durum and bread wheat species.展开更多
Acacia species are found at various arid and semiarid regions. Among the tree genera of family, Fabaceae, Acacia contains the highest number of species. We have collected different species of Acacia from various place...Acacia species are found at various arid and semiarid regions. Among the tree genera of family, Fabaceae, Acacia contains the highest number of species. We have collected different species of Acacia from various places of Saudi Arabia and reconstructed phylogeny for evaluation of genetic relationship among them. Internal transcribed spacer sequence of nrDNA (nrDNA-ITS) locus was used for the reconstruction of phylogeny among these species. Based on phylogenetic tree, Acacia etbaica and A. johnwoodii were close to each other. Similarly, A. ehrenbergiana and A. tortilis were close to each other. Thus, this gene locus was helpful in evaluating the genetic relationship among these species.展开更多
文摘Yellow Rust （stripe） rust （Puccinia striiformis West. f. sp. tritici） is one of the most epidemic diseases infect wheat in cold and wet regions. In 1988, this disease caused a loss of seasonal production amounted 70% on wheat variety Mexipak in Syria, and recurrent infection in 2010, caused by a virulent race called Yr27, caused a considerable loss in the production of bread wheat cultivars （Cham 8, Cham 6 particularly） amounted 90%. Recently, 15 races of yellow rust had been addressed in Syria for seasons 2010-2014; 159E256, 166E254, 166E256, 255 E112, 0 E0, 64 E 6, 230 El50, 0 E 18, 198 El30, 166 El50, 102 El60, 128 E0, 126 El50, 214E150, and 6E16. The race 6E16 was the most frequent during the two seasons, while the race 255El12 was the most virulent, followed by the race 230E222 and the race 0E0 was the weakest one. This study revealed the presence of fourteen newly observed races in Syria. Molecular Variance Analysis of Molecular Variance （AMOVA） of 55 yellow rust Puccinia striiformis f.sp tritici isolates examined by Amplify Fragment Length Polymorphism （AFLP） revealed high genetic variation within population, and the dimensional scale analysis （MSD） and tree diagram showed that the Syrian yellow rust isolates were clustered in three groups： the first group contained isolates derived from durum wheat, the second one contained bread wheat isolates, but the third was made of isolates derived from both durum and bread wheat species.
文摘Acacia species are found at various arid and semiarid regions. Among the tree genera of family, Fabaceae, Acacia contains the highest number of species. We have collected different species of Acacia from various places of Saudi Arabia and reconstructed phylogeny for evaluation of genetic relationship among them. Internal transcribed spacer sequence of nrDNA (nrDNA-ITS) locus was used for the reconstruction of phylogeny among these species. Based on phylogenetic tree, Acacia etbaica and A. johnwoodii were close to each other. Similarly, A. ehrenbergiana and A. tortilis were close to each other. Thus, this gene locus was helpful in evaluating the genetic relationship among these species.
