scholarly journals Characterization and phylogenetic analysis of the complete plastome of Amaranthus retroflexus L. (Amaranthaceae), an annual weeds

2021 ◽  
Vol 6 (10) ◽  
pp. 2847-2848
Author(s):  
Ben-Xia Lou ◽  
Shou-Jin Fan
Keyword(s):  
Phylogenetic Analysis ◽  
Amaranthus Retroflexus ◽  
Annual Weeds

Interference of Annual Weeds in Seedling Alfalfa (Medicago sativa)

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 583-588 ◽  
Author(s):  
Albert J. Fischer ◽  
Jean H. Dawson ◽  
Arnold P. Appleby
Keyword(s):  
Medicago Sativa ◽  
Bromus Tectorum ◽  
Early Spring ◽  
Amaranthus Retroflexus ◽  
Downy Brome ◽  
Weed Interference ◽  
Alfalfa Hay ◽  
Winter Annual ◽  
Annual Weeds

Barnyardgrass [Echinochloa crus-galli(L.) Beauv. #4ECHCG] and pigweeds (mixture ofAmaranthus retroflexusL. # AMARE andA. powelliiS. Wats. # AMAPO) seeded separately with alfalfa (Medicago sativaL.) in mid-August suppressed alfalfa severely before frost killed them in October and November. Some alfalfa was killed, and yield of alfalfa forage was reduced in each of three harvests the following year. These weeds did not harm alfalfa seeded in mid-September. Downy brome (Bromus tectorumL. # BROTE) and tumble mustard (Sisymbrium altissimumL. # SSYAL) suppressed alfalfa seeded in August and September. They reduced alfalfa stands and reduced yield of alfalfa forage in each of three harvests the following year. Alfalfa seeded August 27 and allowed to compete with a mixture of these species for various periods was injured most by weeds that emerged with the alfalfa and remained uncontrolled until forage harvest in May. These weeds did not reduce alfalfa yields if removed by 36 days after alfalfa emergence. Thereafter, yield decreased as the period of weed interference increased. Interference was most damaging in early spring, when growth of winter annual weeds was rapid and vigorous. Weeds seeded 65 or more days after alfalfa emergence did not reduce alfalfa yields but sometimes produced enough biomass to reduce the quality of the first-cutting alfalfa hay.

THE BIOLOGY OF CANADIAN WEEDS.: 44. Amaranthus retroflexus L., A. powellii S. Wats. and A. hybridus L.

1980 ◽  
Vol 60 (4) ◽  
pp. 1215-1234 ◽  
Author(s):  
SUSAN E. WEAVER ◽  
EDWARD L. McWILLIAMS
Keyword(s):  
British Columbia ◽  
Amaranthus Retroflexus ◽  
Biological Information ◽  
Southern Ontario ◽  
Annual Weeds ◽  
Disturbed Habitats

A summary of biological information is provided on Amaranthus retroflexus L., A. powellii S. Wats. and A. hybridus L. These three pigweed species are annual weeds of cultivated fields and other open, disturbed habitats. A. retroflexus is found in all provinces of Canada except Newfoundland. A. powellii is found in British Columbia and in southern Ontario. A. hybridus occurs in southwestern Ontario.

Effect of Early Competition on Growth of Common Milkweed

Weed Science ◽  
1975 ◽  
Vol 23 (1) ◽  
pp. 1-3 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside
Keyword(s):  
Sorghum Bicolor ◽  
Amaranthus Retroflexus ◽  
Setaria Viridis ◽  
Light Competition ◽  
Asclepias Syriaca ◽  
Redroot Pigweed ◽  
Light Soil ◽  
Green Foxtail ◽  
Shoot Weight ◽  
Annual Weeds

Four modes of competition were studied in relation to early development of common milkweed (Asclepias syriacaL.) alone and in competition with green foxtail [Setaria viridis(L.) Beauv], redroot pigweed (Amaranthus retroflexusL.), and sorghum [Sorghum bicolor(L.) Moench ‘RS-626’]. The three species were used to study the effect of no competition, light competition, soil competition, and light and soil (full) competition on common milkweed. Common milkweed height was significantly reduced by soil and full competition with the three species, while only green foxtail caused a significant reduction in height due to light competition. Shoot weight of common milkweed was significantly reduced by light, soil, and full competition by the three species. Reproduction percentage of common milkweed roots was most severely reduced by light and full competition from green foxtail and redroot pigweed. An environment conducive to the establishment of the perennial common milkweed from seed exists when annual weeds are removed by herbicides.

Competition Between Annual Weeds and Sweet Spanish Onions

Weed Science ◽  
1973 ◽  
Vol 21 (5) ◽  
pp. 436-439 ◽  
Author(s):  
G. A. Wicks ◽  
D. N. Johnston ◽  
D. S. Nuland ◽  
E. J. Kinbacher
Keyword(s):  
Allium Cepa ◽  
Amaranthus Retroflexus ◽  
Kochia Scoparia ◽  
Redroot Pigweed ◽  
Annual Weeds

The competitiveness of annual weeds in irrigated sweet Spanish onions (Allium cepaL.) was studied at North Platte, Nebraska, during 1969 and 1970. Weeds allowed to grow in the row for 2, 4, 6, and 8 weeks after onion emergence reduced onion yields 20, 20, 40, and 65%, respectively. When plots were kept weed-free until onion emergence and 2, 4, 6, 8, 10, and 12 weeks after emergence, onion yields were reduced 100, 99, 87, 75, 46, 25, and 5%, respectively. Redroot pigweed (Amaranthus retroflexusL.), kochia (Kochia scopariaL.), and grass weeds accounted for 54, 21, and 21%, respectively, of the total weed yield.

Competition of Late-Emerging Weeds with Sugarbeets

Weed Science ◽  
1977 ◽  
Vol 25 (2) ◽  
pp. 168-170 ◽  
Author(s):  
J.H. Dawson
Keyword(s):  
Beta Vulgaris ◽  
Amaranthus Retroflexus ◽  
Lower Percentage ◽  
Measurable Effect ◽  
Hairy Nightshade ◽  
Annual Weeds

Weed-free sugarbeets [Beta vulgaris(L.) Beauv.] growing at a spacing of 60 cm (1/2 stand) yielded the same weight of roots as those spaced 30 cm (full stand), and those spaced 90 cm (1/3 stand) yielded about 90% as much. Gross sucrose yield was reduced somewhat more, because the larger roots growing in partial stands contained a lower percentage of sucrose than the roots in full stands. Annual weeds that emerged after July 1 were suppressed and. killed by competition from sugarbeets of normal vigor in a full stand, but became competitive when the sugarbeets were spaced at 1/2 or 1/3 of a full stand. Competition from barnyardgrass [Echinochloa crus-galli(L.) Beauv.] and pigweed (mixture ofAmaranthus retroflexusL. andA. powelliiS. Wats.), which reached a height of 150 cm, reduced root yields 5 to 39% in 1/2 stands and 19 to 49% in 1/3 stands, as compared with weed-free sugarbeets in the same stands. Hairy nightshade (Solarium sarachoidesSendt.) was abundant but never became taller than the sugarbeets. Its competition had no measurable effect on the sugarbeets.

Effects of 2,4-D and Dalapon on Weed Seed Production and Dormancy

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 543-547 ◽  
Author(s):  
R. S. Fawcett ◽  
F. W. Slife
Keyword(s):  
Seed Production ◽  
Chenopodium Album ◽  
Datura Stramonium ◽  
Amaranthus Retroflexus ◽  
Common Lambsquarters ◽  
Setaria Faberi ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Before And After ◽  
Annual Weeds

2,4-D [(2,4-dichlorophenoxy)acetie acid] and dalapon (2,2-dichloropropionic acid) were applied to a natural stand of annual weeds at a time near flowering to determine effects on seed production and the dormancy and viability of seeds produced. At rates of 0.6 and 1.1 kg/ha, 2,4-D reduced, respectively the seed production of common lambsquarters(Chenopodium albumL.) 99 and 99%, redroot pigweed(Amaranthus retroflexusL.) 77 and 84%, and jimsonweed(Datura stramoniumL.) 64 and 100%, while giant foxtail(Setaria faberiHerrm) seed production was increased to 307 and 381% of the control, respectively. Dalapon at rates of 2.2 and 4.5 kg/ha reduced respectively seed production of giant foxtail 100 and 100%, and jimsonweed 100 and 91%. Before and after overwinter burial in the soil, common lambsquarters seeds from plants treated with 4.5 kg/ha dalapon were less dormant than control seeds. After overwintering, redroot pigweed seeds from dalapon-treated plants were less dormant than controls, and more seeds survived the winter burial. Common lambsquarters and redroot pigweed seeds from plants treated with 1.1 kg/ha 2,4-D were more dormant than control seeds before overwintering,’ while giant foxtail seeds from 2,4-D treated plants were less dormant than controls after overwintering. Viability of seeds produced by herbicide-treated plants, as determined by germination in KCN, was not greatly different from control seeds. Treatment with 2,4-D or dalapon resulted in the production of common lambsquarters seeds which produced seedlings about half as vigorous as controls. Jimsonweed seedlings grown from seeds from 2,4-D-treated plants showed phenoxy herbicide injury symptoms.

COMPETITIVE INTERACTIONS OF ALFALFA AND ANNUAL WEEDS AS AFFECTED BY ALFALFA WEEVIL (COLEOPTERA: CURCULIONIDAE) STUBBLE DEFOLIATION

1989 ◽  
Vol 24 (1) ◽  
pp. 78-83 ◽  
Author(s):  
G. David Buntin
Keyword(s):  
Dry Matter ◽  
Chenopodium Album ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Dry Matter Accumulation ◽  
Weed Species ◽  
Alfalfa Weevil ◽  
Matter Production ◽  
Annual Weeds ◽  
The Impact

The impact of stubble defoliation by alfalfa weevil, Hypera postica (Gyllenhal), larvae on the establishment and growth of selected annual weeds in alfalfa was examined under controlled conditions in the greenhouse. Weed species were large crabgrass, Digitaria sanguinalis (L.) Scop., yellow foxtail grass, Setaria lutescens (Weig.) Hubb., redroot pigweed, Amaranthus retroflexus L. and common lambsquarters, Chenopodium album L. Stubble defoliation increased the survival of all weed species except foxtail grass. Dry matter production of aerial portions of crabgrass, foxtail grass, pigweed and lambsquarters was 28.4, 7.2, 23.7, and 7.3 times greater, respectively, when growing with defoliated than undefoliated alfalfa. Stubble defoliation also enhanced plant height and leaf number of most weed species. Stubble defoliation reduced dry matter accumulation and delayed development of alfalfa regrowth. Alfalfa root dry weight was more adversely affected than top dry weight by stubble defoliation. The presence of weeds did not significantly (P > 0.05) affect the growth and development of defoliated and undefoliated alfalfa. This result suggests that stubble defoliation by alfalfa weevil larvae reduced the competitive ability of alfalfa which allowed weeds to grow and occupy gaps within the alfalfa canopy.

Morphological, histological and molecular characterization of Myxidium cf. rhodei infecting the kidney of Rutilus rutilus

2020 ◽  
Vol 141 ◽  
pp. 39-46
Author(s):  
MD Dorjievna Batueva ◽  
X Pan ◽  
J Zhang ◽  
X Liu ◽  
W Wei ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Molecular Characterization ◽  
Rutilus Rutilus ◽  
Longitudinal Axis ◽  
Suture Line ◽  
Present Species ◽  
Supplementary Data

In the present study, we provide supplementary data for Myxidium cf. rhodei Léger, 1905 based on morphological, histological and molecular characterization. M. cf. rhodei was observed in the kidneys of 918 out of 942 (97%) roach Rutilus rutilus (Linnaeus, 1758). Myxospores of M. cf. rhodei were fusiform with pointed ends, measuring 12.7 ± 0.1 SD (11.8-13.4) µm in length and 4.6 ± 0.1 (3.8-5.4) µm in width. Two similar pear-shaped polar capsules were positioned at either ends of the longitudinal axis of the myxospore: each of these capsules measured 4.0 ± 0.1 (3.1-4.7) µm in length and 2.8 ± 0.1 (2.0-4.0) µm in width. Polar filaments were coiled into 4 to 5 turns. Approximately 18-20 longitudinal straight ridges were observed on the myxospore surface. The suture line was straight and distinctive, running near the middle of the valves. Histologically, the plasmodia of the present species were found in the Bowman’s capsules, and rarely in the interstitium of the host. Phylogenetic analysis revealed that M. cf. rhodei was sister to M. anatidum in the Myxidium clade including most Myxidium species from freshwater hosts.

16S rDNA Sequence based Phylogenetic Analysis of Some Bacterial Phytoplasma

2012 ◽  
Vol 3 (3) ◽  
pp. 302-304
Author(s):  
G. D.Sharma G. D.Sharma ◽  
◽  
* Dhritiman Chanda ◽  
D.K. Jha D.K. Jha
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rdna ◽  
Rdna Sequence ◽  
16S Rdna Sequence
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