scholarly journals GENETIC DIFFERENTIATION IN TEMPERATURE-ENFORCED SEED DORMANCY AMONG GOLF COURSE POPULATIONS OF POA ANNUA L.

1987 ◽  
Vol 107 (3) ◽  
pp. 623-631 ◽  
Author(s):  
LIN WU ◽  
IRENE TILL-BOTTRAUD ◽  
ARMANDO TORRES
Plant Disease ◽  
2007 ◽  
Vol 91 (7) ◽  
pp. 905-905 ◽  
Author(s):  
N. A. Mitkowski

In the fall of 2006, a golf course in Snoqualmie, WA renovated five putting greens with commercially produced Poa annua L. sod from British Columbia, Canada. Prior to the renovation, the greens had been planted with Agrostis stolonifera L. cv. Providence, which was removed during the renovation. In February of 2007, chlorotic patches were observed on the newly established P. annua greens. When the roots were examined, extensive galling was observed throughout plant roots. Galls were slender and twisted in appearance and less than one millimeter long. Upon dissection of washed galls, hundreds of eggs were exuded into the surrounding water droplet and both mature male and female nematodes were observed. Further morphometric examination of males, females, and juvenile nematodes demonstrated that they were Subanguina radicicola (Greef 1872) Paramanov 1967 (1). Amplification of nematode 18S, ITS1, and 5.8S regions, using previously published primers (2), resulted in a 100% sequence match with the publicly available sequence for S. radicicola, GenBank Accession No. AF396366. Each P. annua plant had an average of six galls (with a range of 1 to 8), primarily located within the top 2 cm of the soil. All five new P. annua putting greens at the golf course were infested with the nematode. Additionally, P. annua from two A. stolonifera cv. Providence greens that had not been renovated was infected, suggesting that the population occurred onsite and was not imported from the Canadian sod. S. radicicola has been identified as causing severe damage in New Brunswick, Canada on P. annua putting greens and in wild P. annua in the northwestern United States, but to our knowledge, this is the first report of the nematode affecting P. annua on a golf course in the United States. References: (1) E. L. Krall. Wheat and grass nematodes: Anguina, Subanguina, and related genera. Pages 721–760 in: Manual of Agricultural Nematology. Marcel Dekker, New York, 1991. (2) N. A. Mitkowski et al. Plant Dis. 86:840, 2002.


Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 875-875 ◽  
Author(s):  
P. Titone ◽  
M. Mocioni ◽  
A. Garibaldi ◽  
M. L. Gullino

During January 2002, Agrostis stolonifera and Poa annua turfgrasses on a golf course in Avigliana (northern Italy) exhibited 10- to 45-cm-diameter circular patches when the snow melted from the greens, tees, and fairways. Many patches coalesced to form large areas of strawcolored blighted turfgrass. At the patch margin, infected plants were covered with white-to-gray mycelium. Plants within patches were matted and appeared slimy with mycelium and sclerotia that were light pink, irregularly shaped, and less than 5 mm in diameter. Isolation from infected leaves on potato dextrose agar, supplemented with 100 mg/l of streptomycin sulfate, consistently yielded a fungus with mycelial, sclerotia, and cultural characteristics of Typhula incarnata (1). Pathogenicity tests were performed by spraying a suspension of mycelium and sclerotia, prepared by chopping mycelium and sclerotia produced in potato dextrose broth, onto 8-week-old A. stolonifera plants grown in plastic trays (45 × 30 cm). Trays were maintained at 0°C for 8 weeks in the dark. Blight symptoms developed on inoculated plants after 6 weeks. Non-inoculated plants remained healthy. The pathogen was reisolated from inoculated plants, and the pathogenicity test was repeated once. Typhula blight incited by T. incarnata was reported in Scandinavian countries and in several European countries including Holland, Germany, Austria, and Switzerland (1). To our knowledge, this is the first report of Typhula blight on turfgrass in Italy. Reference: (1) J. D. Smith et al. 1989. Fungal Diseases of Amenity Turf Grasses. E & FN Spong Ltd, London.


HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 457-459
Author(s):  
Eric D. Miltner ◽  
Gwen K. Stahnke ◽  
Geoffrey J. Rinehart ◽  
Paul A. Backman

The recent release of `True-Putt' (previously `DW-184') creeping bluegrass [Poa annua L. f. reptans (Hauskins) T. Koyama] gives turfgrass managers a new option for seeding into annual bluegrass (Poa annua L.) greens. Because little is known about the culture and management of this newly available seeded cultivar, effective methods for seedling establishment into existing turfgrass canopies, both living and dead, were studied. Four surface cultivation treatments were compared for seedbed preparation before seeding into an existing turfgrass canopy. When seeding into dead turf, two passes with vertical mowing units were more effective than hollow-tine cultivation (HTC), solid-tine cultivation (STC), one pass with the vertical mower plus STC, and the uncultivated control during the first year. Differences were not significant during the second year, most likely because of shallower depth of the vertical mower. Plots averaged about 75% cover by 4 weeks after planting during both years, illustrating the rapid establishment potential for `True-Putt'. After seeding into a live turf canopy, seedlings were indistinguishable from the existing turf, making it impossible to evaluate establishment success.


Weed Science ◽  
1989 ◽  
Vol 37 (1) ◽  
pp. 54-59 ◽  
Author(s):  
W. Mary Lush

Morphological and physiological variation among annual bluegrass populations from the green, fairway, and rough were measured to determine the role annual bluegrass infestations outside the green play in maintaining the population in the green. Annual bluegrass populations from the fairway and the rough were similar to each other but differed from that of the green in habit, dry mass production, flowering, seed size, and germination. Seeds from each population established best in the type of turf from which they originated. It is concluded that, since few genotypes were common to the green and its surroundings, the populations in the fairway and rough played little or no role in maintaining the population of the green. The same is likely to be true wherever the management of greens and their surroundings differs sufficiently for marked population differentiation to occur. This finding does not preclude the possibility that some genotypes adapted to the green persist in the surroundings, and that these genotypes serve as sources of seeds for the colonization or reinfestation of annual bluegrass-free greens.


Plant Disease ◽  
2010 ◽  
Vol 94 (11) ◽  
pp. 1379-1379
Author(s):  
S. J. McDonald ◽  
R. M. Averell ◽  
M. E. Glass ◽  
H. M. Young ◽  
T. H. Mysliwiec ◽  
...  

In mid-November 2009, thin, yellow, and irregular-shaped scalloped rings 10 to 25 cm in diameter were observed on 5 to 10% of a golf course putting green in Charles Town, WV. The 20-year-old USGA-specification sand-based green was mowed at 3.1-mm height and consisted of 60% annual bluegrass (Poa annua L.) and 40% creeping bentgrass (Agrostis stoloniferous L. ‘Putter’). Minimum and maximum daily air temperature ranged from 2 to 22°C, respectively, with 38 mm of rainfall during the appearance of rings symptoms. Only affected annual bluegrass plants exhibited a peculiar yellow chlorosis of the upper and lower leaves. A single fungal isolate was obtained from active mycelium found within symptomatic annual bluegrass leaves and grown on potato dextrose agar (PDA) amended with chloramphenicol (0.1 g/liter). Fungal colony morphology (i.e., light yellow with irregular-shaped 2- to 4-mm-diameter sclerotia first appearing off-white but progressing to brown by 21 to 28 days in culture) and sequencing of the internal transcribed spacer (ITS) 5.8S rDNA region with primers ITS1 and ITS4 confirmed the isolate as Waitea circinata var. circinata (Warcup & Talbot) with ≥99% sequence identity with GenBank Accession No. FJ755889 (1,2,4). To confirm pathogenicity, a 6-mm-diameter plug of the isolate was removed from the expanding edge of a 4-day-old culture grown on PDA and placed in contact with the lower leaves of 12-week-old annual bluegrass (0.001 g of surface-sterilized seed per cm2) grown in 5- × 5-cm plastic pots of autoclaved 85% sand and 15% potting soil. Six pots were inoculated with the isolate and six pots were inoculated with an isolate-free agar plug and then placed in a moist chamber at 28°C. Leaf chlorosis and aerial mycelium was observed in all six inoculated pots 8 to 10 days after inoculation, and symptoms were similar to those expressed in the field. All noninoculated plants remained healthy and asymptomatic. W. circinata var. circinata was reisolated from symptomatic leaves and again confirmed by colony traits and sequencing of the ITS-5.8S rDNA region and submitted as GenBank Accession No. HM807582. To our knowledge, this is the first report of brown ring patch in West Virginia and could be economically important because of intensive fungicide practices used to maintain high-quality putting greens on golf courses (3). References: (1) C. Chen et al. Plant Dis. 91:1687, 2007. (2) K. de la Cerda et al. Plant Dis. 91:791, 2007. (3) J. Kaminski and F. Wong. Golf Course Manage. 75:98, 2007. (4) T. Toda et al. Plant Dis. 89:536, 2005.


Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Patrick E. McCullough ◽  
Jialin Yu ◽  
Mark A. Czarnota

A biotype of annual bluegrass with suspected resistance to pronamide was collected from a golf course in Georgia. The objectives of this research were to determine the level of resistance to pronamide and the mechanisms associated with resistance. From POST applications, the pronamide rate that reduced shoot biomass 50% from the nontreated bluegrass measured>10 times higher for the resistant (R) biotype as compared with susceptible (S) biotypes. The R biotype was not controlled by PRE applications of dithiopyr or prodiamine, but was controlled >92% by PRE applications of pronamide at 0.56 and 1.68 kg ha−1. Mature plants (3- to 5-tiller) of the R biotype absorbed 32% less [14C]pronamide than the S biotype after 72 h in hydroponic culture and accumulated 39% less radioactivity per gram basis of dry shoot mass. The R biotype metabolized [14C]pronamide similar to the S biotype, averaging 16% of the extracted radioactivity. The resistance to POST pronamide applications in the R biotype is associated with reduced absorption and translocation compared with the S biotype.


2006 ◽  
Vol 20 (3) ◽  
pp. 722-727 ◽  
Author(s):  
Darren W. Lycan ◽  
Stephen E. Hart

Studies were conducted in 2002 and 2003 on a golf course fairway in New Jersey to compare spring, summer, and fall treatments of bispyribac-sodium for annual bluegrass control and creeping bentgrass tolerance. Single applications at 74, 111, or 148 g ai/ha were applied in May, August, or October. Split applications of 37 followed by (fb) 37 or 74 fb 74 g/ha applied 3 wk apart were also evaluated. Summer-applied bispyribac-sodium did not reduce bentgrass quality, whereas spring and fall treatments reduced turf quality at 3 wk after treatment and fall treatments in 2002 substantially reduced bentgrass quality. Summer treatments were more effective than spring or fall treatments in reducing annual bluegrass cover. Final evaluations revealed 36, 31, 21, and 26% annual bluegrass cover averaged across nontreated, spring-treated, summer-treated, and fall-treated plots, respectively. This study demonstrates that two split applications of bispyribac-sodium at 74 g/ha in summer can effectively reduce annual bluegrass cover while minimizing creeping bentgrass injury.


Weed Science ◽  
2013 ◽  
Vol 61 (1) ◽  
pp. 21-25 ◽  
Author(s):  
J. Scott McElroy ◽  
Michael L. Flessner ◽  
Zhuoyu Wang ◽  
Fenny Dane ◽  
Robert H. Walker ◽  
...  

Annual bluegrass is commonly controlled by acetolactate synthase (ALS)-inhibiting herbicides in managed turfgrass. An annual bluegrass population with suspected resistance to ALS-inhibiting herbicides was collected from Grand National Golf Course in Opelika, AL (GN population). Subsequent testing confirmed resistance of the GN population to foramsulfuron, trifloxysulfuron, bispyribac-sodium (bispyribac), and imazaquin when compared to a susceptible population collected locally at Auburn University (AU population). Sequencing of the ALS gene revealed a point mutation resulting in an amino acid substitution at Trp574. Cloning of the ALS gene surrounding the Trp574 region yielded two distinct ALS gene sequences: one producing Trp574 and one producing Leu574. Trp574 to Leu has been previously correlated with resistance to ALS-inhibiting herbicides. Both AU and GN gene sequences contained other similar silent and missense mutations. This research confirms resistance of annual bluegrass to ALS-inhibiting herbicides with Trp574 to Leu amino acid substitution being the most likely mode of resistance based on past literature.


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