Allelopathic potential of western coneflower (Rudbeckia occidentalis)

1991 ◽  
Vol 69 (12) ◽  
pp. 2806-2808 ◽  
Author(s):  
Dennis E. Ferguson
Keyword(s):  
Great Lakes ◽  
Lactuca Sativa ◽  
Pinus Contorta ◽  
Picea Engelmannii ◽  
Test Species ◽  
Allelopathic Potential ◽  
Water Extracts ◽  
Engelmann Spruce ◽  
And Control ◽  
Control Water

Water extracts and volatiles from western coneflower (Rudbeckia occidentalis Nutt.) were tested for allelopathic potential under controlled laboratory conditions. Test species were lettuce (Lactuca sativa, Lilly Miller Great Lakes), lodgepole pine (Pinus contorta Dougl. ex Loud.), and Engelmann spruce (Picea engelmannii Parry ex Engelm.) using four treatments (leaves–stems, solid caudex, rotting caudex, and control). Water extracts reduced radicle lengths of seeds but had little effect on germination. Volatiles reduced or delayed germination but had little effect on radicle lengths of germinants. Key words: phytotoxin, Pinus contorta, Picea engelmannii.

On the allelopathic potential of certain terpenoids, phenolics, and their mixtures, and their recovery from soil

1997 ◽  
Vol 75 (6) ◽  
pp. 888-891 ◽  
Author(s):  
Inderjit ◽  
Michiyasu Muramatsu ◽  
Hiroyuki Nishimura
Keyword(s):  
Root Growth ◽  
Lactuca Sativa ◽  
Shoot Growth ◽  
Hydroxybenzoic Acid ◽  
Agar Gel ◽  
Test Species ◽  
Allelopathic Potential ◽  
Lactuca Sativa L ◽  
Root And Shoot Growth ◽  
Lower Recovery

A study was conducted to understand the effects of certain phenolics, terpenoids, and their equimolar mixture through agar gel and soil growth bioassays and their recovery from soils. The eight compounds selected for this study were p-hydroxybenzoic acid, ferulic acid, umbelliferone, catechin, emodin, 1,8-cineole, carvone, and betulin. Lettuce (Lactuca sativa L.) was used as test species for agar gel and soil growth bioassays. Root and shoot growth of lettuce was inhibited for all the above except emodin and catechin. However, in soils treated with different phenolics and terpenoids, only root growth of lettuce was inhibited, whereas shoot growth was promoted. Recovery of p-hydroxybenzoic acid and umbelliferone was higher in unautoclaved soils, while that of catechin was lower. Recovery in relation to degradation of compounds and the significance of additive activities of compounds are discussed. Key words: phenolics, allelopathy, terpenoids, soil, Lactuca sativa.

scholarly journals Seed Stratification of Engelmann Spruce and Lodgepole Pine: The Effect of Stratification Duration and Timing of Surface-drying

1986 ◽  
Vol 62 (3) ◽  
pp. 147-151 ◽  
Author(s):  
Yasuomi Tanaka ◽  
L. M. Harper ◽  
N. J. Kleyn
Keyword(s):  
Key Words ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Early Spring ◽  
Picea Engelmannii ◽  
Cool Temperature ◽  
Standard Temperature ◽  
Engelmann Spruce ◽  
Surface Drying ◽  
Picea Engelmanni

Based on the speed and completeness of laboratory germination and nursery bed emergence, the present study showed that for both Engelmann spruce (Picea engelmannii [Parry] Engelmann) and lodgepole pine (Pinus contorta Dougl.): (1) longer stratification generally improved the rate, and in some cases completeness, of germination more so under a cool temperature (15 °C/5 °C) regime than under a warm, standard temperature (30 °C/20 °C) regime emphasizing its importance for early spring outdoor sowing under suboptimal germination temperatures, (2) for a given stratification period, surface-drying at the end of stratification was at least as effective as surface-drying prior to or during stratification, and (3) stratification periods of 6 weeks or longer were generally the most effective. A 6- to 8-week stratification with seeds surface-dried at the end of stratification is recommended for nursery sowing of both species. Key Words: stratification, pinus contorta, Picea engelmanni, laboratory germination, nursery bed emergence.

scholarly journals Recolonization of Substrates Burned in the 1988 Yellowstone Park Fires by Cryptogams (Lichens, Mosses, Fungi)

2001 ◽  
Vol 25 ◽  
pp. 113-118 ◽  
Author(s):  
Sharon Eversman
Keyword(s):  
Vascular Plants ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Picea Engelmannii ◽  
Engelmann Spruce ◽  
Seed Sources ◽  
Initial Return ◽  
Forested Areas ◽  
Study Sites ◽  
One Year

The fires of 1988 in Yellowstone National Park burned 1.1 million acres (1719.4 square miles) within the park boundaries, about 44.5% of the park. Six per cent of the area burned was meadow­grassland and 94% was forests. Most of the forested areas that burned were dominated by lodgepole pine (Pinus contorta Dougl. ex Loud), with smaller tracts of Douglas fir (Pseudotsuga menziesii (Mirbel) Franco)), Engelmann spruce (Picea engelmannii Parry) and whitebark pine (Pinus albicaulis Engelm.). The burns were mosaic in nature, leaving different sizes of areas severely burned, moderately burned and unburned, and adjacent patches of mostly ground fires, mostly canopy fires, both ground and canopy fires or unburned stands (Rothermel et al., 1994). Many park projects have documented recovery of vascular plants, especially lodgepole pine and the understory perennials (Anderson & Romme, 1991; Baskin, 1999; Foster, et al, 1999; Reed, et al ,1999; Tomback, et al, 2001; Turner et al, 1994, 1997). The conclusions were that lodgepole pine has regenerated itself, as expected, from seed sources in adjacent unburned patches. Herbaceous and shrubby understory regeneration has depended primarily on the plants that were present at the study sites before the fires, with regrowth from surviving underground parts as well as from nearby seed sources. This study investigates the initial return of non-vascular vegetation, lichens and mosses, all of which were presumably destroyed when their substrates were burned. None of the other Yellowstone studies included cryptogam observations. Studies concentrating on recolonizing cryptogamic crusts, including mosses, algae and lichens, on dryland soil after fires, have occurred in Utah (Johansen, et al, 1984) and Australia (Eldridge & Bradstock, 1994). Algae tended to return before lichens and mosses, especially during wet years, and after five years the lichens and mosses were recovering but not yet to pre-burn cover. Researchers have found that, on limestone, two lichen species colonized after four years. Thomas, et al. (1994) found that Ceratodon purpureus appeared to be insensitive to pH differences of burned peat surfaces and readily colonized ashed surfaces within one year after fire; Polytrichum piliferum was dominant after three years.

Experimental Study of the Impact of Alisma plantago-aquatica Secretions on Pathogenic Bacteria

2014 ◽  
Vol 1 (3) ◽  
pp. 3-7
Author(s):  
O. Zhukorskyy ◽  
O. Hulay
Keyword(s):  
Pathogenic Bacteria ◽  
Initial Density ◽  
Biologically Active ◽  
Erysipelothrix Rhusiopathiae ◽  
Natural Focus ◽  
Test Species ◽  
Popula Tions ◽  
And Control ◽  
The Impact

Aim. To estimate the impact of in vivo secretions of water plantain (Alisma plantago-aquatica) on the popula- tions of pathogenic bacteria Erysipelothrix rhusiopathiae. Methods. The plants were isolated from their natural conditions, the roots were washed from the substrate residues and cultivated in laboratory conditions for 10 days to heal the damage. Then the water was changed; seven days later the selected samples were sterilized using fi lters with 0.2 μm pore diameter. The dilution of water plantain root diffusates in the experimental samples was 1:10–1:10,000. The initial density of E. rhusiopathiae bacteria populations was the same for both experimental and control samples. The estimation of the results was conducted 48 hours later. Results. When the dilution of root diffusates was 1:10, the density of erysipelothrixes in the experimental samples was 11.26 times higher than that of the control, on average, the dilution of 1:100 − 6.16 times higher, 1:1000 – 3.22 times higher, 1:10,000 – 1.81 times higher, respectively. Conclusions. The plants of A. plantago-aquatica species are capable of affecting the populations of E. rhusiopathiae pathogenic bacteria via the secretion of biologically active substances into the environment. The consequences of this interaction are positive for the abovementioned bacteria, which is demon- strated by the increase in the density of their populations in the experiment compared to the control. The intensity of the stimulating effect on the populations of E. rhusiopathiae in the root diffusates of A. plantago-aquatica is re- ciprocally dependent on the degree of their dilution. The investigated impact of water plantain on erysipelothrixes should be related to the topical type of biocenotic connections, the formation of which between the test species in the ecosystems might promote maintaining the potential of natural focus of rabies. Keywords: Alisma plantago-aquatica, in vivo secretions, Erysipelothrix rhusiopathiae, population density, topical type of connections.

Characterization of the bacterial flora associated with root systems of Pinus contorta var. latifolia

1978 ◽  
Vol 24 (12) ◽  
pp. 1520-1525 ◽  
Author(s):  
J. A. Dangerfield ◽  
D. W. S. Westlake ◽  
F. D. Cook
Keyword(s):  
Amino Acid ◽  
Pinus Contorta ◽  
Bacterial Flora ◽  
Root Systems ◽  
Growth Media ◽  
Agricultural Crops ◽  
Control Soil ◽  
Mature Tree ◽  
And Control

Root systems of young and mature lodgepole pine (Pinus contorta Dougl. var. latifolia Englem.) were removed from forest stands and the associated aerobic bacterial flora isolated. Characterization of rhizoplane and control soil isolates from these tree root systems demonstrated differences from that reported for agricultural crops. Ammonifying, proteolytic, and amylolytic organisms were proportionately reduced within the rhizoplane. The rhizoplane organisms grew more slowly than the control soil isolates, although they responded in greater numbers to the addition of an amino acid supplement to the growth media. The rhizoplane organisms also showed an increased ability to solubilize phosphate. The chitinolytic organisms were suppressed within the rhizoplane of the mature tree but were stimulated by the young trees. With this exception, the rhizoplane microflora of older and younger trees were similar.

Comparison of Terpene Composition in Engelmann Spruce (Picea engelmannii) Using Hydrodistillation, SPME and PLE

2004 ◽  
Vol 59 (9-10) ◽  
pp. 641-648 ◽  
Author(s):  
Marek Mardarowicz ◽  
Dorota Wianowska ◽  
Andrzej L. Dawidowicz ◽  
Ryszard Sawicki
Keyword(s):  
Essential Oils ◽  
Steam Distillation ◽  
Solid Phase ◽  
Picea Engelmannii ◽  
Enzymatic Reactions ◽  
Plant Materials ◽  
Engelmann Spruce ◽  
Pressurised Liquid Extraction ◽  
Conifer Trees ◽  
Spruce Needles

Abstract Terpenes emitted by conifer trees are generally determined by analysing plant extracts or essential oils, prepared from foliage and cones using steam distillation. The application of these procedures limits experiments to cut plant materials. Recently headspace techniques have been adopted to examine terpene emission by living plants. This paper deals with the application of solid-phase micro-extraction (SPME) for the analysis of terpenes emitted by conifers foliage of Engelmann spruce (Picea engelmannii), including its seedlings. The compositions of SPME extracts obtained for destroyed and non-destroyed old and juvenile spruce needles were compared with the compositions of essential oils and pressurised liquid extraction (PLE) extracts corresponding to the same plant materials. No substantial differences have been found in the qualitative terpene composition estimated by analysing essential oil and PLE and SPME extracts from non-destroyed old and juvenile foliage. The disintegration of spruce needles results in the formation of a significant amount of myrcene in the case of the old conifer foliage and non-terpenoic compounds in the case of juvenile conifer foliage. This phenomenon can be attributed to enzymatic reactions occurring in the destroyed plant cells.

Factors influencing understory seedling establishment of Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in southeast Wyoming

1982 ◽  
Vol 60 (12) ◽  
pp. 2753-2761 ◽  
Author(s):  
Alan K. Knapp ◽  
William K. Smith
Keyword(s):  
Seedling Establishment ◽  
Rocky Mountain ◽  
Field Measurements ◽  
Incident Radiation ◽  
Picea Engelmannii ◽  
Abies Lasiocarpa ◽  
Northern Rocky Mountains ◽  
Medicine Bow Mountains ◽  
Engelmann Spruce ◽  
Surface Drying

Although seedlings of Abies lasiocarpa are generally more abundant than those of Picea engelmannii in the understory of mature spruce–fir forests throughout the central and northern Rocky Mountains, little information exists concerning environmental or plant factors that may influence the establishment of these two conifers. Field measurements in the Medicine Bow Mountains of southeast Wyoming showed that seedlings of A. lasiocarpa had greater photosynthetic rates at low understory light levels and required lower levels of incident radiation for saturation of photosynthesis compared with those of P. engelmannii. However, both conifers occurred in understory locations where total daily solar radiation was equally low (<2 MJ∙m−2∙day−1) and thus, a lack of light did not appear to be responsible for the low number of P. engelmannii seedlings in the understory. In contrast, seedlings of P. engelmannii were substantially more abundant at locations with thinner litter layers compared with those of A. lasiocarpa. Also, laboratory studies showed that the smaller seeds of P. engelmannii germinated more rapidly and at lower temperatures than seeds of A. lasiocarpa although growth of tap roots on A. lasiocarpa seedlings was greater initially ([Formula: see text] longer in 2-week-old seedlings) as well as for 10-week-old seedlings (50% longer). The deeper penetrating tap root of A. lasiocarpa seedlings may enable this conifer to establish more abundantly on thick, rapidly drying litter layers that are characteristic of mature spruce–fir forests. In contrast, establishment of P. engelmannii seedlings may be limited to microsites without a thick litter layer such as disturbed areas or decomposing wood, where surface drying may occur more gradually throughout the summer. These results are discussed in terms of the potential effects of seedling establishment on the observed patterns in climax vegetation of central and northern Rocky Mountain subalpine forests.

Allelopathic potential of Artemisia campestris ssp. caudata on Lake Huron sand dunes

1997 ◽  
Vol 75 (11) ◽  
pp. 1903-1912 ◽  
Author(s):  
Kyeong W. Yun ◽  
M. A. Maun
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Mycorrhizal Fungi ◽  
Sand Dune ◽  
Sand Dunes ◽  
Dry Weight ◽  
Fungal Colonization ◽  
Test Species ◽  
Allelopathic Potential ◽  
Artemisia Campestris

Greenhouse studies were conducted to test allelopathic effects of Artemisia campestris ssp. caudata on seed germination and seedling growth of several sand-dune species and colonization by mycorrhizal fungi. The aqueous extracts of A. campestris showed no inhibitory effect on seed germination, seedling elongation, or dry-weight growth of plants at lower concentrations (10 and 50%), but 100% concentration of the extracts caused varying degrees of inhibition depending on the test species. The mixing of dry leaves of seedlings of A. campestris to the sand showed severe inhibition of Elymus canadensis seedlings. The percent germination of test species in soil from the rhizosphere of A. campestris was significantly lower than that of the control. The leaf area and dry weight were also lower but the differences were not significant. The aqueous extract inhibited mycorrhizal fungal colonization in roots of three sand-dune grasses. Key words: allelopathy, Artemisia campestris ssp. caudata, seed germination, seedling growth, mycorrhizal fungi.

scholarly journals Microbial fertilizer from PK rocks on lettuce nutrients and soil attributes in consecutive crops

2021 ◽  
Vol 56 ◽  
Author(s):  
Wagner da Silva Oliveira ◽  
Newton Pereira Stamford ◽  
Emmanuella Vila Nova da Silva ◽  
Thatiana Stamford Arnaud ◽  
Carlos Garcia Izquierdo ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Residual Effect ◽  
Successive Cycle ◽  
Total N ◽  
Soil Attributes ◽  
Positive Effects ◽  
Plant Characteristics ◽  
And Control ◽  
Potassic Rocks ◽  
Microbial Fertilizers

Abstract: The objective of this work was to evaluate the effect of a microbial fertilizer, produced from phosphate and potassic rocks and earthworm compost, as an alternative to conventional fertilizers, on lettuce (Lactuca sativa) nutrients and soil attributes. The experiment was conducted in consecutive cycles (30 and 60 days) in a soil from the Lorca region, in the municipality of Murcia, Spain. The fertilization treatments were: conventional fertilizer, 100% of the recommended rate (RR); microbial fertilizer, 50% of the RR (5 Mg ha-1); microbial fertilizer, 100% of the RR (10 Mg ha-1); microbial fertilizer, 150% of the RR (15 Mg ha-1); and control, without N-P2O5-K2O fertilization. The microbial fertilizers applied at 100 and 150% of the RR showed significant and positive effects, as well as the best results for plant characteristics. The microbial fertilizer increased total N and available P and K compared with the conventional fertilizer. A residual effect was observed in the successive cycle. The effectiveness of the microbial fertilizer shows it is a viable alternative to conventional fertilizers, with positive effects on plant productivity and soil attributes.

scholarly journals Allelopatic effects of Waltheria indica L.: Biocontrol potential in ecological

2021 ◽  
Vol 10 (13) ◽  
pp. e235101321263
Author(s):  
Bruno Santos Francisco ◽  
Felipe Bueno Dutra ◽  
Emerson Viveiros ◽  
Raquel Passaretti ◽  
Rafael Paranhos Martins ◽  
...  
Keyword(s):  
Ecological Restoration ◽  
Aqueous Extract ◽  
Lactuca Sativa ◽  
Native Species ◽  
Initial Step ◽  
Cellular Respiration ◽  
Aqueous Extracts ◽  
Test Species ◽  
Leaves And Roots ◽  
Urochloa Brizantha

In Brazil, most degraded areas are occupied by exotic and invasive species, which require alternatives for their management. We evaluated the allelopathic effects of Waltheria indica in the laboratory from aqueous extracts of leaves and roots on the germination of the species Lactuca sativa L. (lettuce), Urochloa brizantha (Hochst. ex A.Rich.) RDWebster (brachiaria) and Handroanthus chrysotrichus (Mart. ex DC.) Mattos (yellow Ipe). We collected adult one-year-old Waltheria indica shrubs in ecological restoration areas by direct seeding. We used two treatments with aqueous extracts of leaves and roots and a control without extract, with ten repetitions of 10 seeds per treatment, totaling 600 seeds per test species. Germination and use of tetrazolium assays to evaluate the potential respiratory activity of the roots were used. The aqueous extract of W.indica leaves affected the number of germinated seeds of all test species, while the aqueous extract of roots affected only L. sativa and H. chrysotrichus. There were no significant differences between treatments (leaf and root extracts) in species germination. The aqueous extracts of Waltheria indica leaves and roots affected germination and cellular respiration of the studied species, mainly in Lactuca sativa. The identification of W. indica allelopathic compounds may be an initial step so that in the future new bioherbicides are produced from extracts of this species, or even that its seeds can be sown together with non-sensitive native species, aiming for control of exotic species in ecological restoration projects.

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