Bromus setifolius var. pictus (Hook) Skottsb., B. setifolius var. setifolius Presl. and B.setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius ...

M any natural landscapes have undergone dramatic permanent alterations as a result of human activities, including conversion to cultural landscapes; such changes are readily observed and understood. However, extensive ecological change can also occur in regional landscapes that are maintained in a seminatural state, changes that go largely unrecognized because the regional landscape retains an ...

Throughout the western United States, the invasive annual grass, medusahead (Taeniatherum caputmedusae L. Nevski), is rapidly invading grasslands once dominated by native perennial grasses, such as bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A). It is also invading grasslands dominated by less undesirable invasive annual grasses, especially cheatgrass (Bromus tectorum L.). Understandi...

historical records of cheatgrass Bromus tectorum invasion in North American sagebrush-steppe Sumanta Bagchi*, David D. Briske, Brandon T. Bestelmeyer and X. Ben Wu Department of Ecosystem Science and Management, Texas A&M University, 2138 TAMU, College Station, TX 77843, USA; USDA-ARS, Jornada Experimental Range and Jornada Basin LTER, New Mexico State University, MSC 3JER, Box 30003, Las Cruce...

We investigated the effects of chemical variation in thyme (Thymus vulgaris L.) on its interactions with competitors, herbivores, and herbivore predators. Four different thyme monoterpene phenotypes (chemotypes) were grown in a 4x2x2 factorial of chemotype, caging (sham half-cages vs. full cages), and competition (control vs. the grass Bromus madritensis L.). Cages reduced numbers of arthropod ...

nomic relationships among species (Vosa, 1975; Cai and Chinnappa, 1987; Fominaya et al., 1988; Gill and Sears, Previous cytogenetic studies of the genus Bromus L. were limited 1988; Tayyar et al., 1994; Falistocco et al., 1995). The to chromosome counts and construction of karyotypes on the basis of Feulgen staining. Since the chromosomes of Bromus are similar in C-banding procedure has not bee...

Rhynchosporium consists of two species, R. secalis and R. orthosporum. Both are pathogens of grasses with R. secalis infecting a variety of Poaceae hosts and R. orthosporum infecting Dactylis glomerata. Phylogenetic analyses of multilocus DNA sequence data on R. secalis isolates originating from cultivated barley, rye, triticale and other grasses, including Agropyron spp., Bromus diandrus and H...

negatively affected by disturbance. meadow barley (Hordeum brachyantherum Nevski) (Hickman 1993). Purple needlegrass, blue wildrye, bluegrass and California melic are droughttolerant species that typically occupy well-drained upland sites. In contrast, creeping wildrye and meadow barley are less drought-tolerant and typically grow in the moist soils of seeps, streams and wetland margins (Walker...

Finch H., Allen P., Meyer S. (2013): Exposure to low water potentials and seed dormancy favour the fungus in the Pyrenophora semeniperda–Bromus tectorum pathosystem. Plant Protect. Sci., 49 (Special Issue): S15–S20. In semi-arid regions of the United States, Pyrenophora semeniperda kills seeds of the winter annual Bromus tectorum. We report on pathosystem outcomes under manipulated water potent...