107 research outputs found
Supplemental Material - Spousal Cognitive Status and Risk for Declining Cognitive Function and Dementia: The Atherosclerosis Risk in Communities Study
No full textSupplemental Material for Spousal Cognitive Status and Risk for Declining Cognitive Function and Dementia: The Atherosclerosis Risk in Communities Study by Mark Lee, Ryan T. Demmer, Anna Kucharska-Newton, B. Gwen Windham, Priya Palta, Tetyana Shippee, Pamela L. Lutsey in Journal of Aging and Health.</p
Effect of delivery method and population size of <i>Trichoderma harzianum</i> on growth response of unrooted chrysanthemum cuttings
No full text In a previous study, addition of Trichoderma harzianum Rifai isolate T-12 to a propagative medium resulted in improved performance of chrysanthemum cuttings. However, root and shoot growth of one cultivar, 'Dark Bronze Charm', were more responsive to a lower (5 g T-12/kg medium) than higher (25 g T-12/kg medium) rate of fungal propagules, suggesting potential phytotoxicity at higher concentrations. The objectives of this study were to investigate higher rates of T-12 medium amendment for phytotoxicity, and to examine an alternative method of delivering the fungus to the propagative medium in order to obtain a more uniform response from cuttings. Isolate T-12 was added to the propagative medium as either a powdered peat-bran amendment (0, 5, or 50 g T-12 /kg medium) or as alginate prills (80 or 800 g T-12/kg medium). There were no differences among treatments on day seven, but by day 21, shoot fresh weight and heights were significantly greater for plants treated with prills at 800 g T-12/kg medium. Both prill treatments resulted in greater shoot height on day 14 and 21 than all other treatments, which were similar to controls. Amendment with T-12 powder at 50 g/kg increased root length, but 80 g/kg medium added as prills decreased root dry weight compared to the control. The highest rate of T-12 (800 g prills/kg medium) had no effect on root growth. This suggests that moderate, rather than high rates of T-12 are more effective in promoting rooting of unrooted chrysanthemum, and that there is a potential for phytotoxic effects on root growth with higher rates.Key words: Dendranthema X grandiflorum, plant growth promotion, plant propagation. </jats:p
Trichoderma spp. in innovative substrates for ornamental plants
No full textTrichoderma spp. are free-living fungi commonly widespread in soil and root ecosystems. Recent discoveries show them as opportunistic, avirulent plant symbionts as well as parasites of other fungi. Some strains establish robust and long-lasting colonization of roots by entering into the first epidermal layers. Root colonization frequently results in enhancing of growth and development, crop productivity or induction of resistance to abiotic and biotic factors.
Peat, mainly imported from the northern and eastern European regions, is the basic constituent of organic substrates commonly utilized in the cultivation of ornamental plants in pots or in benches. During the past few years, the supply of the peat is hampered by environmental and economical constraints. Recently, the European Commission decided to exclude all substrates containing peat from the release of the Community Eco-Label Mark. In this optic the need to reduce peat in ornamental substrates devised great attention and resulted in pressing and increasing research activity to set up new and innovative substrates for ornamental market.
The aim of the present PhD thesis is to select beneficial fungi belonging to Trichoderma genus, to be add as soil inoculants, in order to develop an innovative, economical and suitable substrate alternative to peat for cultivation of seed plants (Limonium sinuatum and Cupressus sempervirens) and of acidophilus species (Camellia japonica) of ornamental interest. The activity involved the selection of Trichoderma spp. isolates for their ability to grow in the roots, as endophytes, or in the rhizosphere, to protect plants against plant pathogens or to act as plant growth promoters. The preliminary screening for endophytism resulted in 10 interesting isolates (out of 162) for Limonium sinuatum, 9 (out of 162) for Cupressus sempervirens and 8 (out of 202) for Camellia japonica. From following rounds of screening, three Trichoderma isolates, among which T. asperellum 2046 in common for all the species, confirmed the best endophytic performance and improved growth.
The antagonistic activity of these selected strains, against fungal plant pathogens as Sclerotinia sclerotiorum, S. minor, Colletotrichum gleospoiroides and Rhizoctonia solani, has been evaluated in order to analyse if these isolates could be considered good beneficial fungi. In addition. T2046 was evaluated in biocontrol experiments on Limonium, against S. sclerotiorum and S. minor with mycoparasistim investigated as principal mechanisms.
Encouraging results herewith obtained, suggest that T. asperellum 2046 could be taken into account as bioactive ingredient of new biopesticide and/or biofertilizer to be used as inoculant for innovative substrates for ornamental plants
‘Appalachian Joy’ is a Supernumerary, White-bracted Cultivar of Flowering Dogwood (Cornus florida) Resistant to Powdery Mildew (Erysiphe pulchra)
No full textIncidence of Arthropods Infested with Conidia of the Dogwood Anthracnose Fungus, Discula destructiva Redlin, on Flowering Dogwoods in the Natural Environment
No full textArthropods were collected from flowering dogwoods infected with Discula destructiva Redlin, causal agent of dogwood anthracnose, to evaluate their ability to transport viable conidia. During 1994, 7.2% of all arthropods collected (n = 375) from diseased trees at three sites in the Great Smoky Mountains National Park were carrying viable conidia of D. destructiva. Most [92.6% (25/27)] of the conidia-infested arthropods were collected during June when sporulation and spread of dogwood anthracnose were increasing. From July through September, the expansion of disease severity and incidence of sporulation diminished and the frequency of conidia-infested arthropods decreased. Several species of arthropods with viable conidia of D. destructiva were collected lending support to the hypothesis that insects and other arthropods may play a role in the spread of dogwood anthracnose.</jats:p
Improved wetland soil organic carbon stocks of the conterminous U.S. through data harmonization
No full text© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Uhran, B., Windham-Myers, L., Bliss, N., Nahlik, A. M., Sundquist, E., & Stagg, C. L. Improved wetland soil organic carbon stocks of the conterminous U.S. through data harmonization. Frontiers in Soil Science, 1, (2021): 706701, https://doi.org/10.3389/fsoil.2021.706701.Wetland soil stocks are important global repositories of carbon (C) but are difficult to quantify and model due to varying sampling protocols, and geomorphic/spatio-temporal discontinuity. Merging scales of soil-survey spatial extents with wetland-specific point-based data offers an explicit, empirical and updatable improvement for regional and continental scale soil C stock assessments. Agency-collected and community-contributed soil datasets were compared for representativeness and bias, with the goal of producing a harmonized national map of wetland soil C stocks with error quantification for wetland areas of the conterminous United States (CONUS) identified by the USGS National Landcover Change Dataset. This allowed an empirical predictive model of SOC density to be applied across the entire CONUS using relational %OC distribution alone. A broken-stick quantile-regression model identified %OC with its relatively high analytical confidence as a key predictor of SOC density in soil segments; soils 6% OC (organic wetland soils, 15% of the dataset) had virtually no predictive relationship of %OC to SOC density (RMSE = 0.0348 g C cm−3, ~56% mean RMSE). Disaggregation by vegetation type or region did not alter the breakpoint significantly (6% OC) and did not improve model accuracies for inland and tidal wetlands. Similarly, SOC stocks in tidal wetlands were related to %OC, but without a mappable product for disaggregation to improve accuracy by soil class, region or depth. Our layered harmonized CONUS wetland soil maps revised wetland SOC stock estimates downward by 24% (9.5 vs. 12.5Pg C) with the overestimation being entirely an issue of inland organic wetland soils (35% lower than SSURGO-derived SOC stocks). Further, SSURGO underestimated soil carbon stocks at depth, as modeled wetland SOC stocks for organic-rich soils showed significant preservation downcore in the NWCA dataset (<3% loss between 0 and 30 cm and 30 and 100 cm depths) in contrast to mineral-rich soils (37% downcore stock loss). Future CONUS wetland soil C assessments will benefit from focused attention on improved organic wetland soil measurements, land history, and spatial representativeness.This project was funded through the U.S. Geological Survey's Land Carbon Program and a grant to ES through the U.S. Geological Survey's Community for Data Integration Program for generating cross-agency assessments
Enhanced Root and Shoot Growth of Chrysanthemum Cuttings Propagated with the Fungus Trichoderma harzianum
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