Literatura científica selecionada sobre o tema "Persicaria perfoliata"

Abstract The introduced invasive vine mile-a-minute weed Persicaria perfoliata (formerly Polygonum perfoliatum) is continuing to spread throughout the Mid-Atlantic states and beyond, from its initial site of introduction near York, Pennsylvania. This weed frequently interferes with forest regeneration and until recently had few natural enemies attacking it in its introduced range. In 2004, a permit for field release of a host-specific Asian weevil Rhinoncomimus latipes was obtained, and the weevil has since been released in five states. The weevil has established well and is beginning to impact growth and development of the weed.

Seven species, viz., Calamagrostis stoliczkai Hook. f., Juncus bracteatus Buchen., Matthiola flavida Boiss., Parrya nudicaulis (L.) Regel, Persicaria perfoliata (L.) H. Gross, Ptilotrichum canescens (DC.) C. Meyer and Stellaria tibetica Kurz have been recorded from Pin Valley National Park, Lahaul-Spiti as new additions to the flora of Himachal Pradesh.

AbstractMile-a-minute weed or devil's tearthumb (Polygonum perfoliatum, syn. =Persicaria perfoliata) is an invasive annual vine in the Mid-Atlantic and Northeastern United States that reproduces solely through seeds. Our study aimed to identify how mile-a-minute seed viability is affected by time of year and the maturity of the fruit surrounding the achene. Full-sized immature (green) and mature (blue) fruits were collected from five field sites every 2 wk over a 3 mo period, and seed viability was assessed using a triphenyl tetrazolium chloride (TZ) assay. At the onset of seed production in mid-August, 35% of seeds from immature fruits were viable. This percentage increased steadily, peaking at 84% in late September before declining at some sites around the time of the first frost. In contrast nearly all seeds with mature fruits (96%) were viable at all collection dates. Thus land managers who apply physical or chemical control methods for mile-a-minute weed should do so before the onset of any seed production and not simply before fruit maturation. If it is necessary to apply control methods after fruit set, it should be done as early in the season as possible.

β-sitosterol (1) and β-sitosterol-D-glucoside (2) were isolated from the dichloromethane soluble fraction of a methanol extract of the leave of Persicaria perfoliata. The crude fraction was subjected to antimicrobial screening and brine shrimp lethality bioassay, where moderate antimicrobial activity was observed against most of the test organisms was seen. The hexane soluble fraction also displayed significant cytotoxic activity with LC50 0.64 μg/ml in brine shrimp lethality bioassay. This is the first report of occurrence of these compounds from this plant. Bangladesh Pharmaceutical Journal 22(2): 224-227, 2019

Mile-a-minute (Persicaria perfoliata (L.) H. Gross; family: Polygonaceae) is an exotic annual barbed vine that has invaded the northeastern USA and Oregon (2). In July of 2010, in a search for potential biological control pathogens (3), diseased P. perfoliata plants were found along the Firtina River near Ardesen, Turkey. Symptoms were irregular dark necrotic lesions along leaf margins and smaller irregular reddish lesions on the lamellae of leaves. Symptomatic leaves were sent to the quarantine facility of FDWSRU, USDA, ARS in Ft. Detrick, MD, for pathogen isolation and testing. Symptomatic leaves were excised, surface disinfested in 0.615% NaOCl, and then incubated for 2 to 3 days in sterile moist chambers at 20 to 25°C. Numerous waxy sub-epidermal acervuli with 84-μm-long (mean) black setae were observed in all of the lesions after 2 to 3 days of incubation. Conidiophores within acervuli were simple, short, and erect. Conidia were one-celled, hyaline, guttulate, subcylindrical, straight, 12.3 to 18.9 × 3.0 to 4.6 μm (mean 14.3 × 3.7 μm). Pure cultures were obtained by transferring conidia onto 20% V-8 juice agar. Appressoria, formed 24 h after placing conidia on dialysis membrane over V-8 juice agar, were smooth, clavate, aseptate, regular in outline, and 6.4 to 10.0 × 5.1 to 7.2 μm (mean 7.5 × 6.6 μm). These characters conformed to the description of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (1). A voucher specimen was deposited in the U.S. National Fungus Collections (BPI 882461). Nucleotide sequences for the internal transcribed spacers (ITS 1 and 2), directly sequenced from ITS 1 and ITS 4 standard primers (4), were deposited in GenBank (JN887693). A comparison of these sequences with ITS 1 and 2 sequences of the C. gloeosporioides epitype IMI 356878 (GenBank EU 371022) (1) using BLAST found 479 of 482 identities with no gaps. Conidia from 14-day-old cultures, in an aqueous suspension of 1.0 × 106 conidia ml–1, were spray-inoculated onto healthy stems and leaves of twenty 30-day-old P. perfoliata plants. Another 10 plants were not inoculated. All plants were placed in a dew chamber at 25°C for 16 h with no lighting. They were then placed in a 20 to 25°C greenhouse with a 14-h photoperiod. Light was generated using 400W sodium vapor lights. Lesions developed on leaves and stems of all inoculated plants after 7 days, and symptoms were the same as observed in the field. Each plant was rated weekly for disease severity on a 0 to 10 rating scale where 0 = no disease symptoms and 10 = 100% symptomatic tissue. After 28 days, the average disease rating of inoculated plants was 3.95 ± 0.94. No disease developed on noninoculated plants. C. gloeosporioides was reisolated from all inoculated plants. Host range tests will determine the potential of this isolate as a biological control agent for P. perfoliata. To our knowledge, this is the first report of anthracnose caused by C. gloeosporioides on P. perfoliata. References: (1) P. F. Cannon et al. Mycotaxon 104:189, 2008. (2) J. T. Kartesz and C. A. Meacham. Synthesis of the North American Flora, Version 1.0., North Carolina Botanical Garden, Chapel Hill, N.C. 1999. (3) D. L. Price et al. Environ. Entomol. 32:229, 2003. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, Inc., San Diego, CA, 1990.