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David R Huff - One of the best experts on this subject based on the ideXlab platform.
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Instability of the Greens‐Type Phenotype in Poa Annua L.
Crop Science, 2011Co-Authors: Jonathan M. La Mantia, David R HuffAbstract:The turfgrass species Poa Annua L. is most prevalent as an invasive, Annual weed in managed turfs. Conversely, the dwarf perennial greens-type biotype produces a high turf quality with great utility to the golf-course industry. In the past 60 yr, several attempts have been made to breed a commercial cultivar of the greens-type biotype with little sustained success. Here, we characterize the morphological traits of the greens-type phenotype and investigate its inheritance and stability through genetic crosses. The results indicate that the greens-type phenotype links single-branching inflorescences with reductions in culm length, tiller length, leaf length, and panicle length to a single genetic mechanism. However, in advanced-generation progeny, the segregation of the greens-type phenotype does not conform to the disomic single-gene inheritance model. Tetrasomic inheritance, gene complementation, and quantitative inheritance models are also presented. These results, along with the observation of somatic reversions, suggest that the greens-type phenotype is unstable and may be regulated by an epigenetic mechanism.
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instability of the greens type phenotype in Poa Annua l
Crop Science, 2011Co-Authors: Jonathan M. La Mantia, David R HuffAbstract:The turfgrass species Poa Annua L. is most prevalent as an invasive, Annual weed in managed turfs. Conversely, the dwarf perennial greens-type biotype produces a high turf quality with great utility to the golf-course industry. In the past 60 yr, several attempts have been made to breed a commercial cultivar of the greens-type biotype with little sustained success. Here, we characterize the morphological traits of the greens-type phenotype and investigate its inheritance and stability through genetic crosses. The results indicate that the greens-type phenotype links single-branching inflorescences with reductions in culm length, tiller length, leaf length, and panicle length to a single genetic mechanism. However, in advanced-generation progeny, the segregation of the greens-type phenotype does not conform to the disomic single-gene inheritance model. Tetrasomic inheritance, gene complementation, and quantitative inheritance models are also presented. These results, along with the observation of somatic reversions, suggest that the greens-type phenotype is unstable and may be regulated by an epigenetic mechanism.
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Tolerance to simulated ice encasement and Microdochium nivale in USA selections of greens-type Poa Annua
Acta Agriculturae Scandinavica Section B - Plant Soil Science, 2009Co-Authors: T. S. Aamlid, Peter J. Landschoot, David R HuffAbstract:Abstract Lack of winter hardiness is a limitation to the use of Annual meadowgrass (Poa Annua f. reptans) on golf course putting greens in northern climates. Our objectives were 1) to assess the tolerance of 13 selections of Annual meadowgrass to simulated ice encasement (SIE) and pink snow mould (PSM, Microdochium nivale); 2) to determine if these tolerances were interrelated or related to plant concentrations of water soluble carbohydrates (WSC); and 3) to determine if tolerance to SIE can be associated with accumulation of toxic substances. Samples of the Annual meadowgrass selections were taken from an experimental green at University Park, Pennsylvania, on four dates from 23 Nov. 2005 until 27 Mar. 2006. Samples of creeping bentgrass (Agrostis stolonifera L.) ‘Penn A-4’ were included for comparison in studies on SIE and WSC. Samples were vacuum-sealed in plastic bags at 1°C for SIE and inoculated with three isolates of M. nivale for PSM tolerance. Small, but significant, differences were found among ...
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salinity tolerance of 33 greens type Poa Annua experimental lines
Crop Science, 2008Co-Authors: Jing Dai, Maxim J Schlossberg, David R HuffAbstract:Current literature suggests Poa Annua L. (Annual bluegrass) is intolerant to salinity stress. Response of greens-type Poa Annua to chronic salinity stress (12 wk at 8.0 dS m -1 ) was evaluated over two greenhouse experiments. Vegetative samples of 33 greens-type P. Annua experimental lines were maintained at a 6.4-mm mowing height and irrigated daily with modified Hoagland's solutions possessing salinity levels of 0.7 dS m -1 (nonsaline control) or 8.0 dS m -1 (NaCI treatment, approaching 0.25 strength sea water, approx. 13.5 dS m -1 ). Clipping yield dry weight (CYD) and leaf water content (LWC) were measured weekly. Digital images were collected at the end of weeks 1, 4, 8, and 12 to determine percentage cover (PC) and dark green color index (DGCI). Across all lines, all sample dates, and both experiments, salinity stress significantly reduced PC (30.8%), DGCI (9.3%), CYD (33.9%), and LWC (3.3%) compared with nonsaline controls (a = 0.05), suggesting chronic salinity stress is detrimental to greens-type P. Annua quality. However, significant differences in relative PC and relative CYD were observed among lines, indicating that substantial variation in salinity tolerance exists in greens-type P. Annua. Numerous greens-types P. Annua experimental lines, such as PSU 99-9-21, PSU 01-1-46, and PSU 05-1-14, possess moderate-to-good salinity tolerance and are potentially suitable for use on golf courses with moderate salt problems.
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Salinity Tolerance of 33 Greens‐Type Poa Annua Experimental Lines
Crop Science, 2008Co-Authors: Jing Dai, Maxim J Schlossberg, David R HuffAbstract:Current literature suggests Poa Annua L. (Annual bluegrass) is intolerant to salinity stress. Response of greens-type Poa Annua to chronic salinity stress (12 wk at 8.0 dS m -1 ) was evaluated over two greenhouse experiments. Vegetative samples of 33 greens-type P. Annua experimental lines were maintained at a 6.4-mm mowing height and irrigated daily with modified Hoagland's solutions possessing salinity levels of 0.7 dS m -1 (nonsaline control) or 8.0 dS m -1 (NaCI treatment, approaching 0.25 strength sea water, approx. 13.5 dS m -1 ). Clipping yield dry weight (CYD) and leaf water content (LWC) were measured weekly. Digital images were collected at the end of weeks 1, 4, 8, and 12 to determine percentage cover (PC) and dark green color index (DGCI). Across all lines, all sample dates, and both experiments, salinity stress significantly reduced PC (30.8%), DGCI (9.3%), CYD (33.9%), and LWC (3.3%) compared with nonsaline controls (a = 0.05), suggesting chronic salinity stress is detrimental to greens-type P. Annua quality. However, significant differences in relative PC and relative CYD were observed among lines, indicating that substantial variation in salinity tolerance exists in greens-type P. Annua. Numerous greens-types P. Annua experimental lines, such as PSU 99-9-21, PSU 01-1-46, and PSU 05-1-14, possess moderate-to-good salinity tolerance and are potentially suitable for use on golf courses with moderate salt problems.
Halina Galera - One of the best experts on this subject based on the ideXlab platform.
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Seed germination and invasion success of Poa Annua L. in Antarctica
Acta Societatis Botanicorum Poloniae, 2018Co-Authors: Agnieszka Rudak, Katarzyna J Chwedorzewska, Halina Galera, Anna Znój, Maciej WodkiewiczAbstract:One of the first steps to successful invasion of plant species that reproduce sexually is seed germination, which may be highly influenced by climatic conditions. We studied Poa Annua , a cosmopolitan species found across all climatic zones and the only alien species that has successfully colonized the Antarctic. Our research questions were: (i) if harsh polar conditions restrict seed germination of P. Annua and (ii) if the germination capacity of the Antarctic population of the species is due to high germination aptitude in the source population. We compared germination of seeds collected from eight populations around the world (maritime Antarctica, S Chile, W Argentina and E Argentina, NE USA, SW Croatia, C Poland and S Poland). We followed germination of seeds collected in the field and acquired from plants cultivated under unified optimal conditions. We found significant differences between populations in germination characteristics of seeds collected in the field. These could be associated with seed ripening in different locations. Seeds obtained under favorable conditions differed in stratification requirements. The germination potential of the Antarctic population is lowered by unfavorable polar conditions impacting seed maturation. Thus, the species’ invasion in the Antarctic seems highly restricted by the harsh environment. Environmental unsuitability may restrict invasions of other species in the same way potentially. However, this environmental barrier protecting Antarctica from invasions may be broken under a climate warming scenario.
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How much of the invader's genetic variability can slip between our fingers? A case study of secondary dispersal of Poa Annua on King George Island (Antarctica).
Ecology and evolution, 2017Co-Authors: Maciej Wodkiewicz, Katarzyna J Chwedorzewska, Piotr T. Bednarek, Anna Znój, Piotr Androsiuk, Halina GaleraAbstract:We studied an invasion of Poa Annua on King George Island (Maritime Antarctic). The remoteness of this location, its geographic isolation, and its limited human traffic provided an opportunity to trace the history of an invasion of the species. Poa Annua was recorded for the first time at H. Arctowski Polish Antarctic Station in the austral summer of 1985/6. In 2008/9, the species was observed in a new locality at the Ecology Glacier Forefield (1.5 km from "Arctowski"). We used AFLP to analyze the genetic differences among three populations of P. Annua: the two mentioned above (Station and Forefield) and the putative origin of the introduction, Warsaw (Poland). There was 38% genetic variance among the populations. Pairwise ФPT was 0.498 between the Forefield and Warsaw populations and 0.283 between Warsaw and Station. There were 15 unique bands in the Warsaw population (frequency from 6% to 100%) and one in the Station/Forefield populations (which appears in all analyzed individuals from both populations). The Δ(K) parameter indicated two groups of samples: Warsaw/Station and Forefield. As indicated by Fu's Fs statistics and an analysis of mismatch distribution, the Forefield population underwent a bottleneck and/or founder effect. The Forefield population was likely introduced by secondary dispersal from the Station population.
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Poa Annua l in the maritime antarctic an overview
Polar Record, 2015Co-Authors: Katarzyna J Chwedorzewska, Maciej Wodkiewicz, Irena Gielwanowska, Maria Olech, Marco A Molinamontenegro, Halina GaleraAbstract:Poa Annua is the only flowering plant species that has established a breeding population in the maritime Antarctic, through repeated anthropogenic introduction. The first appearance of this species in the Antarctic was observed in 1953. Annual bluegrass inhabits mainly anthropogenic sites, but recently has entered tundra communities. The functioning of P. Annua in the Antarctic could not have been possible without adaptations that enable the plants to persist in the specific climatic conditions typical for this zone. Poa Annua is highly adaptable to environmental stress and unstable habitats: huge phenotypic and genotypic variability, small size, plastic life cycle (life-history types ranging from Annual to perennial forms). The spreading of P. Annua in the Antarctic Peninsula region is a classic example of the expansion process following anthropogenic introduction of an invasive species, and illustrates the dangers to Antarctic terrestrial ecosystems that are associated with increasing human traffic.
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diaspores of the introduced species Poa Annua l in soil samples from king george island south shetlands antarctica
Arctic Antarctic and Alpine Research, 2013Co-Authors: Maciej Wodkiewicz, Halina Galera, Katarzyna J Chwedorzewska, Irena Gielwanowska, Maria OlechAbstract:Abstract The soil seed bank and seed germination capacity of Poa Annua in the vicinity of the Polish Antarctic Station (South Shetlands, Antarctica) were investigated. It was documented that Annual bluegrass can reproduce sexually and produce a functional seed bank of close to 5000 seeds/m2 under maritime Antarctic conditions. Comparison of germination between Poa Annua and two native plant species revealed that Poa Annua seeds can germinate as fast or even faster than native species, and are more vigorous. Our studies show that in the Antarctic Poa Annua can successfully reproduce sexually and produce fully developed, viable caryopses that are able to survive the maritime Antarctic winter, not only in a soil bank, but also directly in the previous year's inflorescences.
Jamie B. Kirkpatrick - One of the best experts on this subject based on the ideXlab platform.
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changes in subantarctic heard island vegetation at sites occupied by Poa Annua 1987 2000
Arctic Antarctic and Alpine Research, 2005Co-Authors: Jj Scott, Jamie B. KirkpatrickAbstract:Abstract Poa Annua, the only alien plant species recorded on subantarctic Heard Island, considerably expanded its range and abundance along three transects in tundra-like vegetation on the island in the period 1987–2000. This expansion was strongly associated with increased seal disturbance, which also favored Callitriche antarctica and damaged Pringlea antiscorbutica, leading to a decrease in mean vegetation height. Expansions of Azorella selago and Poa cookii were independent of the expansion of P. Annua, relating to colonization of moraines. There was no evidence of displacement of other taxa by Poa Annua in areas undisturbed by seals.
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Changes in Subantarctic Heard Island Vegetation at Sites Occupied by Poa Annua, 1987–2000
Arctic Antarctic and Alpine Research, 2005Co-Authors: Jj Scott, Jamie B. KirkpatrickAbstract:Abstract Poa Annua, the only alien plant species recorded on subantarctic Heard Island, considerably expanded its range and abundance along three transects in tundra-like vegetation on the island in the period 1987–2000. This expansion was strongly associated with increased seal disturbance, which also favored Callitriche antarctica and damaged Pringlea antiscorbutica, leading to a decrease in mean vegetation height. Expansions of Azorella selago and Poa cookii were independent of the expansion of P. Annua, relating to colonization of moraines. There was no evidence of displacement of other taxa by Poa Annua in areas undisturbed by seals.
Jj Scott - One of the best experts on this subject based on the ideXlab platform.
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changes in subantarctic heard island vegetation at sites occupied by Poa Annua 1987 2000
Arctic Antarctic and Alpine Research, 2005Co-Authors: Jj Scott, Jamie B. KirkpatrickAbstract:Abstract Poa Annua, the only alien plant species recorded on subantarctic Heard Island, considerably expanded its range and abundance along three transects in tundra-like vegetation on the island in the period 1987–2000. This expansion was strongly associated with increased seal disturbance, which also favored Callitriche antarctica and damaged Pringlea antiscorbutica, leading to a decrease in mean vegetation height. Expansions of Azorella selago and Poa cookii were independent of the expansion of P. Annua, relating to colonization of moraines. There was no evidence of displacement of other taxa by Poa Annua in areas undisturbed by seals.
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Changes in Subantarctic Heard Island Vegetation at Sites Occupied by Poa Annua, 1987–2000
Arctic Antarctic and Alpine Research, 2005Co-Authors: Jj Scott, Jamie B. KirkpatrickAbstract:Abstract Poa Annua, the only alien plant species recorded on subantarctic Heard Island, considerably expanded its range and abundance along three transects in tundra-like vegetation on the island in the period 1987–2000. This expansion was strongly associated with increased seal disturbance, which also favored Callitriche antarctica and damaged Pringlea antiscorbutica, leading to a decrease in mean vegetation height. Expansions of Azorella selago and Poa cookii were independent of the expansion of P. Annua, relating to colonization of moraines. There was no evidence of displacement of other taxa by Poa Annua in areas undisturbed by seals.
Bradley D Hanson - One of the best experts on this subject based on the ideXlab platform.
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epsps duplication and mutation involved in glyphosate resistance in the allotetraploid weed species Poa Annua l
Pest Management Science, 2019Co-Authors: Caio Augusto De Castro Grossi Brunharo, Sarah Morran, Katie Martin, Marcelo L Moretti, Bradley D HansonAbstract:BACKGROUND Poa Annua is a widespread winter Annual weed species in California. Recently, poor control of this species with glyphosate was reported by growers in an almond orchard in California with a history of repetitive glyphosate use. The objectives of this research were to evaluate the level of glyphosate resistance in a developed S4 P. Annua line (R) and identify the mechanisms of resistance involved. RESULTS Whole-plant dose-response experiments confirmed glyphosate resistance in R, which required 18-fold more glyphosate to achieve a 50% growth reduction compared with a susceptible line (S), results that were supported by the lower shikimate accumulation observed in R compared with S. No differences in glyphosate absorption, translocation, or metabolism were observed, suggesting that non-target-site mechanisms of resistance are not involved in the resistance phenotype. A missense single nucleotide polymorphism was observed in EPSPS coding position 106 in R, resulting in a leucine to proline substitution. This polymorphism was observed exclusively in P. supina EPSPS homeologs. A seven-fold increase in the number of copies of EPSPS alleles was observed in R compared with S. CONCLUSIONS We report the first case of glyphosate resistance associated with both EPSPS duplication and target-site mutation at position 106, leading to high levels of glyphosate resistance in the allotetraploid weed species Poa Annua L. Data obtained in this research will be useful for the development of diagnostic tools for rapid glyphosate resistance identification, monitoring and containment. © 2018 Society of Chemical Industry.
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rapid publicationdiuron resistant Poa Annua is resistant to norflurazon
Weed Science, 2009Co-Authors: Bradley D Hanson, Carol A MallorysmithAbstract:Abstract Poa Annua control with norflurazon was different between two field trials in 1999. At the field site with suspected diuron-resistant P. Annua, control was less than at the site with known diuron-susceptible P. Annua. Diuron-resistant and -susceptible biotypes of P. Annua were subjected to a range of norflurazon rates in the greenhouse. The diuron-resistant P. Annua biotype (R/S : of 2.5) was collected in 1995 from a Lolium perenne L. seed production field near Tangent, OR. The R/S : for norflurazon in these experiments was 4.8; thus, confirming that diuron-resistant P. Annua is resistant to norflurazon. Nomenclature: Diuron; norflurazon; Poa Annua L. PoaAN, Annual bluegrass; Lolium perenne L. LOLPE, perennial ryegrass.
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diuron resistant Poa Annua is resistant to norflurazon
Weed Science, 2000Co-Authors: Bradley D Hanson, Carol A MallorysmithAbstract:Carol A. Mallory-Smith Department of Crop and Soil Science, Oregon State University, Corvallis, OR 97331-3002 Poa Annua control with norflurazon was different between two field trials in 1999. At the field site with suspected diuron-resistant 1? Annua, control was less than at the site with known diuron-susceptible 1? Annua. Diuron-resistant and -susceptible biotypes of P? Annua were subjected to a range of norflurazon rates in the greenhouse. The diuron-resistant P Annua biotype (R/S ratio of 2.5) was collected in 1995 from a Lolium perenne L. seed production field near Tangent, OR. The R/S ratio for norflurazon in these experiments was 4.8; thus, confirming that diuron-resistant P Annua is resistant to norflurazon.
