John Keat’s journey to an understanding of the poet’s place in society

M.A. University of Kansas, English 196

Cross-tolerance to abiotic stresses in halophytes: Application for phytoremediation of organic pollutants

International audienceHalopytes are plants able to tolerate high salt concentrations but no clear definition was retained for them. In literature, there are more studies that showed salt-enhanced tolerance to other abiotic stresses compared to investigations that found enhanced salt tolerance by other abiotic stresses in halophytes. The phenomenon by which a plant resistance to a stress induces resistance to another is referred to as cross-tolerance. In this work, we reviewed cross-tolerance in halophytes at the physiological, biochemical, and molecular levels. A special attention was accorded to the cross-tolerance between salinity and organic pollutants that could allow halophytes a higher potential of xenobiotic phytoremediation in comparison with glycophytes

Facilitation of American Chestnut ( Castanea dentata

This study evaluated the influence of planting sites on the establishment and ectomycorrhizal (ECM) colonization of American chestnut (Castanea denetata (Marsh.) Borkh.) on an abandoned coal mine in an Appalachian region of the United States. Root morphotyping and sequencing of the fungal internal transcribed spacer (ITS) region were used to identify the ECM species associated with the chestnut seedlings. Germination, survival, ECM root colonization, and growth were assessed in three habitats: forest edge, center (plots without vegetation), and pine plots (a 10-year-old planting of Pinus virginiana). Seedlings in pine plots had higher survival (38%) than the other plot types (center 9% and forest edge 5%; P=0.007). Chestnuts found colonized by ECM within the pine plots were larger (P=0.02), contributed by a larger root system (P=0.03). Forest edge and pine plots had more ECM roots than seedlings in center plots (P=0.04). ITS fungal sequences and morphotypes found among chestnut and pine matched Scleroderma, Thelephora, and Pisolithus suggesting these two plant species shared ECM symbionts. Results indicated that the presence of P. virginiana had a greater facilitative effect on growth and survival of chestnut seedlings

Soil Metals and Ectomycorrhizal Fungi Associated with American Chestnut Hybrids as Reclamation Trees on Formerly Coal Mined Land

Hybrid chestnut (Castanea dentata × C. mollissima) has the potential to provide a valuable agroforestry crop on formerly coal mined landscapes. However, the soil interactions of mycorrhizal fungi and buried metals associated with mining are not known. This study examined soil, plant tissue, and ectomycorrhizal (ECM) root colonization on eight-year-old hybrid (BC1F3 and BC2F3) and American chestnuts on a reclaimed coal mine in Ohio, USA. Chestnut trees were measured and ECM colonization on roots was quantified. Leaves, flowers, and soil were analyzed for heavy metals. Differences were not detected among tree types regarding metal accumulation in plant tissue or ECM colonization. BC2F3 hybrids had greater survival and less cankers than American chestnuts (P = 0.006 and <0.0001). Taller trees were associated with greater ECM root colonization and correlated with an increase in Al uptake (P = 0.02 and 0.01). When comparing tissue, manganese and aluminum were in higher concentrations in leaves than flowers, where copper and selenium were significantly higher in floral tissue (P < 0.05). All trees were flowering at this time meriting further examination in nut tissue. Block effects for selenium and zinc indicate the variability in reclaimed soils requiring further monitoring for possible elemental transfer to nut and wood tissue

Carefully timed burning can control barb goatgrass

Barb goatgrass is a noxious annual grass that is rapidly invading California's grassland ecosystems. No effective control strategies for managing barb goatgrass have been available that do not simultaneously injure other more desirable grass and broadleaf species. In our study at the UC Hopland Research and Extension Center, we conducted prescribed burning in late spring or early summer before barb goatgrass seeds had reached maturation. One year of prescribed burning was not sufficient to control re-establishment the following year. However, 2 years of complete burning gave effective control of barb goatgrass while increasing native perennial grass cover and native species richness, particularly legumes. The success of the goatgrass control was directly proportional to the completeness of the second-year burn