abstract recent interest in describing the spatial distribution patterns of weeds through using interpolation methods has increased to estimate weed seedling density from spatially refferenced data and evaluation of applicable to site-specific weed management. in this research, a multi layer perceptron neural network (mlpnn) model was developed to predict the spatial distribution of h. glaucum ...

Numerous hybrid and polypoid species are found within the Triticeae. It has been suggested that the H subgenome of allopolyploid Elymus (wheatgrass) species originated from diploid Hordeum (barley) species, but the role of hybridization between polyploid Elymus and Hordeum has not been studied. It is not clear whether gene flow across polyploid Hordeum and Elymus species has occurred following ...

Molecular karyotypes of Hordeum bogdanii Wilensky, 1918 (2n = 14), and Hordeum brevisubulatum Link, 1844 ssp. brevisubulatum (2n = 28), were characterized by physical mapping of several repetitive sequences. A total of 18 repeats, including all possible di- or trinucleotide SSR (simple sequence repeat) motifs and satellite DNAs, such as pAs1, 5S rDNA, 45S rDNA, and pSc119.2, were used as probes...

The phylogenetic position of hexaploid Elymus repens within the tribe Triticeae (Poaceae) was examined using cloned sequences from the low-copy nuclear genes encoding phosphoenolpyruvate carboxylase (pepC) and beta-amylase. A previous analysis of E. repens using data from the nuclear granule-bound starch synthase I (GBSSI) gene had yielded five phylogenetically distinct gene copies, two more th...

Eight wild Hordeum species: H. bogdanii, H. intercedens, H. jubatum, H. lechleri, H. marinum, H. murinum, H. patagonicum, and H. secalinum, and cultivated barley (H. vulgare) were grown in nutrient solution containing 0.2 (control), 150, 300, or 450 mol m(-3) NaCl. In saline conditions, the wild Hordeum species (except H. murinum) had better Na+ and Cl- 'exclusion', and maintained higher leaf K...

The barley grasses (Hordeum glaucum Steud. and Hordeum leporinum Link.) are important weeds of crops and pastures in South Australia. Populations of both species have evolved resistance to paraquat, primarily following intensive use of paraquat for winter weed control in lucerne (Medicago sativa L.) crops. In the past few years, agricultural consultants have been reporting an increase in proble...

Four accessions of hexaploid Elymus repens from its native Central European distribution area were analyzed using sequencing of multicopy (internal transcribed spacer, ITS) and single-copy (granule-bound starch synthase I, GBSSI) DNA in concert with genomic and fluorescent in situ hybridization (GISH and FISH) to disentangle its allopolyploid origin. Despite extensive ITS homogenization, nrDNA ...

Hordeum, distributed worldwide in temperate zones, is the second largest genus in the tribe Triticeae and includes diploid, tetraploid, and hexaploid species. We determined, by DAPI staining and flow cytometry, the nuclear DNA content for 35 accessions of the genus Hordeum, from a total of 19 species, including specimens of 2 cultivars and 2 landraces of Hordeum vulgare ssp. vulgare as well as ...