Effects of sand deposition on the interaction between Ammophila arenaria, plant-parasitic nematodes, and pathogenic fungi

1995 ◽  
Vol 73 (8) ◽  
pp. 1141-1150 ◽  
Author(s):  
P. C. E. M. de Rooij – van der Goes ◽  
W. H. van der Putten ◽  
B. A. M. Peters
Keyword(s):  
Root Zone ◽  
Stem Elongation ◽  
Pathogenic Fungi ◽  
Parasitic Nematodes ◽  
Ammophila Arenaria ◽  
Soil Organisms ◽  
Sand Burial ◽  
Potted Plants ◽  
Sand Accumulation ◽  
Upward Growth

Ammophila arenaria is a dominant sand-fixing plant species of the European coastal foredunes. It remains vigorous under regular burial conditions on seaward slopes, but starts to degenerate when sand accumulation diminishes. Several hypotheses have been put forward to explain this degeneration. In this study, we test the hypothesis that upward growth of plants following sand burial enables them to escape harmful soil organisms. Plants in a degenerating field stand of A. arenaria and potted plants grown in sterilized sand (outdoor pot experiment) were buried with sterilized or nonsterilized sand. Burial in both sterilized and nonsterilized sand resulted in stem elongation, increased numbers of living shoots, and increased shoot and root biomass. However, when plants were grown in and buried with sterilized sand, the numbers of shoots were significanlty higher than those buried with nonsterilized sand. The new root zone of buried plants was colonized by pathogenic soil organisms (nematodes and fungi) during the same growing season. It is concluded that by upward growth through pathogen-free sand, the plants benefit, at least temporarily, from escaping its pathogens and parasites. Key words: clonal growth, upward growth, migration, soil-borne disease, growth reduction.

Harmful soil organisms in coastal foredunes involved in degeneration of Ammophila arenaria and Calammophila baltica

1990 ◽  
Vol 68 (7) ◽  
pp. 1560-1568 ◽  
Author(s):  
W. H. Van der Putten ◽  
S. R. Troelstra
Keyword(s):  
Root Zone ◽  
Sand Dunes ◽  
Beach Sand ◽  
Parasitic Nematodes ◽  
Ammophila Arenaria ◽  
Soil Organisms ◽  
Marram Grass ◽  
Windblown Sand ◽  
Harmful Organisms ◽  
Mobile Dunes

The presence of harmful soil organisms in the root zone of Ammophila arenaria (marram grass) was examined by biotesting. For this investigation three locations along the sandy shoreline of The Netherlands were chosen: Voorne, Texel, and Schouwen. At all three locations harmful organisms were detected in sand from stable dunes, as well as in sand from mobile dunes (degenerated and vigorous A. arenaria, respectively). In beach sand, however, no harmful organisms occurred. Since A. arenaria shows vigorous growth only when it is buried regularly by windblown sand from the beach, it is concluded that this sand deposition enables the plants to escape from harmful soil organisms. Ammophila arenaria and Calammophila baltica (purple or hybrid marram grass) from the Voorne location were grown outdoors in containers filled with sand from the beach, the mobile dunes, and the stable dunes, and sterilized sand from the stable dunes. Biomass production of both species was highest in sterilized sand from the stable dune, followed by (in descending order) beach sand, sand from the mobile dune, and unsterilized sand from the stable dune. As compared with A. arenaria, however, growth of C. baltica was reduced less and without mortality of cuttings. Degree of growth reduction by harmful soil organisms could not be related to numbers of plant parasitic nematodes. Key words: Ammophila arenaria, Calammophila baltica, coastal sand dunes, succession, harmful soil organisms.

Long-term Effects of Triazol Growth Regulators on Stem Elongation of Rhododendron and Kalmia

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 436E-436
Author(s):  
Martin P.N. Gent
Keyword(s):  
Dose Response ◽  
Growth Regulator ◽  
Stem Elongation ◽  
Spray Application ◽  
Long Term Effects ◽  
Potted Plants ◽  
Response Coefficient ◽  
Wide Range ◽  
Second Year

The persistence of effects of paclobutrazol or uniconazol on stem elongation was determined for several years after large-leaf Rhododendron and Kalmia latifolia were treated with a single-spray application of these triazol growth-regulator chemicals. Potted plants were treated in the second year from propagation, and transplanted into the field in the following spring. The elongation of stems was measured in the year of application and in the following 2 to 4 years. Treatments with a wide range of doses were applied in 1991, 1992, or 1995. For all except the most-dilute applications, stem elongation was retarded in the year following application. At the highest doses, stem growth was inhibited 2 years following application. The results could be explained by a model of growth regulator action that assumed stem elongation was inversely related to amount of growth regulator applied. The dose response coefficient for paclobutrazol was less than that for uniconazol. The dose that inhibited stem elongation one-half as much as a saturating dose was about 0.5 and 0.05 mg/plant, for paclobutrazol and uniconazol, respectively. The dose response coefficient decreased exponentially with time after application, with an exponential time constant of about 2/year. The model predicted a dose of growth regulator that inhibited 0.9 of stem elongation immediately after application would continue to inhibit 0.5 of stem elongation in the following year.

scholarly journals Nematocidial activity of aqueous solutions of plants of the families Cupressaceae, Rosaceae, Asteraceae, Fabaceae, Cannabaceae and Apiaceae

2019 ◽  
Vol 27 (3) ◽  
pp. 227-232 ◽  
Author(s):  
O. O. Boyko ◽  
V. V. Brygadyrenko
Keyword(s):  
Aqueous Solutions ◽  
Cannabis Sativa ◽  
Root Zone ◽  
Taraxacum Officinale ◽  
Ambrosia Artemisiifolia ◽  
Biologically Active ◽  
Parasitic Nematodes ◽  
Foeniculum Vulgare ◽  
Conium Maculatum ◽  
Nematode Larvae

In natural ecosystems of animals, introduction of larvae of parasitic nematodes into the litter layer from excrement facilitates their migration and search of new host vertebrate animals. In such conditions they are constantly affected by biologically active substances of the abundant species of plants which grow in pastures. Currently, the influence of substances present in the above-ground part of plants on the vitality of larvae of helminths in the environment remains unstudied. In this article, we present the results of our research on the nematocidial activity in vitro in the aqueous solutions of 21 species of plants distributed in the territory of Steppe Ukraine: Sanguisorba officinalis L., Rosa canina L., Crataegus sanguinea Pall., Crataegus pentagyna Waldst. & Kit. ex Willd., Armeniaca vulgaris Lam., Taraxacum officinale F. H. Wigg., Iva xanthiifolia Nutt., Artemisia campestris L., Arctium minus (Hill) Bernh., Ambrosia artemisiifolia L., Cannabis sativa L., Humulus lupulus L., Melilotus officinalis (L.) Pall., Vicia cracca L., Lotus ucrainicus Klok., Onobrychis arenaria (Kit.) DC., Foeniculum vulgare Mill., Eryngium planum L., Conium maculatum L., Juniperus communis L., Thuja occidentalis L. The level of vitality of nematode larvae of the Strongylida (Haemonchus contortus (Rudolphi, 1803)) and Rhabditida (Strongyloides papillosus (Wedl, 1856)) orders varied depending on the species of plant, and also five experimental concentrations in aqueous solutions tested in seven replications. The most notable nematocidial effect was exerted by Taraxacum officinale F. H. Wigg. – we observed death of larvae of third stage development L3 H. contortus and larvae of first-third stages L1–3 S. papillosus at 24 h exposure to 3% aqueous solution. Three percent aqueous solutions of S. officinalis and A. artemisiifolia displayed nematocidial properties only against S. papillosus: death of L1–3 S. papillosus was observed. Aqueous solutions of R. canina, A. vulgaris, A. minus, H. lupulus, V. cracca, L. ucrainicus, O. arenaria, E. planum, C. maculatum, J. communis, Th. occidentalis had lethal effect only on non-invasive larvae (larvae of the first and second stage L1–2) of S. papillosus. They displayed no nematocidial properties towards invasive larvae of H. contortus and S. papillosus. At exposure to aqueous solutions of the rest of the studied species of plants, over 50% of L3 H. contortus and L1–3 S. papillosus larvae remained alive. The determined patterns allow us to state that while living in the litter and soil in the root zone of plants nematode larvae undergoa negative influence caused by some plant species.

The occurrence of root-infecting fungi and parasitic nematodes in annual Medicago spp. in Western Australian pastures

2000 ◽  
Vol 51 (4) ◽  
pp. 435 ◽  
Author(s):  
M. P. You ◽  
K. Sivasithamparam ◽  
I. T. Riley ◽  
M. J. Barbetti
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
Pathogenic Fungi ◽  
Parasitic Nematodes ◽  
Fungal Isolates ◽  
As Species ◽  
Significant Damage ◽  
Pathogenicity Tests ◽  
Annual Medicago

Asurvey of 30 medic pastures for root-rots was undertaken in Western Australia and pathogenicity tests of representative fungal isolates from roots sampled were conducted to determine the main factors contributing to medic decline and the association between those factors. In particular, the contribution of pathogenic fungi and nematodes to medic root-rot in Western Australia was studied. From a total of 30 000 pieces of root plated, 3836 fungal isolates were obtained and identified at least to genus level. Four hundred and seventy-two representative isolates were tested for in vitro pathogenicity in Medicago sphaerocarpos cv. Orion. Of these, 32 were further tested in the glasshouse. The pathogenicity tests indicated that 56% of isolates were capable of causing significant damage to the root system and it is likely that pathogenic fungi are largely responsible for medic root-rot in the field. In contrast, the number of Pratylenchus spp. in the roots was not found to relate to disease symptoms. It is concluded that soil-borne pathogenic fungi such as species of Pythium, Fusarium, and Phoma contribute significantly to medic pasture decline in Western Australia.

Soil abiotic factors associated with Meloidogyne spp. and Pratylenchus spp. populations in sugarcane

Nematology ◽  
2020 ◽  
pp. 1-13
Author(s):  
Marissônia de A. Noronha ◽  
Marcelo F. Fernandes ◽  
Maria de Fatima S. Muniz ◽  
Elvira Maria R. Pedrosa ◽  
Mayara C. Assunção ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Root Zone ◽  
Abiotic Factors ◽  
Regression Tree ◽  
Parasitic Nematodes ◽  
Population Densities ◽  
Multivariate Regression Tree ◽  
Soil Variables ◽  
Meloidogyne Spp

Summary Meloidogyne spp. and Pratylenchus spp. are the most damaging plant-parasitic nematodes to sugarcane and the knowledge of soil characteristics that influence the occurrence of these pathogens can be useful in their management. With the objective to investigate the relationships between soil variables and populations of Meloidogyne spp. and Pratylenchus spp. in sugarcane fields, root-zone soil and root samples were collected from 20 farms located in 16 municipalities in Alagoas state, Brazil. The multivariate regression tree technique was used to model the population density’s response variables for Meloidogyne spp. and Pratylenchus spp. in the root-zone soil and the roots according to sugarcane cultivars, soil organic matter, and soil chemical and physical variables. The results showed the existence of associations between soil factors, sugarcane cultivars and populations of nematodes. Root samples from soils with K > 37.79 mmolc dm−3, Al < 5.93 mmolc dm−3 and sugarcane ‘RB92579’, ‘SP753046’, ‘SP813250’ and ‘SP921631’ showed the lowest Pratylenchus spp. population densities. However, the lowest densities in the root-zone were found in soils with sum of bases > 1.91 mmolc dm−3, Ca:Mg ratio < 1:2 and soil organic matter < 10.7 g dm−3. The lowest population densities of Meloidogyne spp. in roots were associated with sugarcane ‘RB92579’, ‘RB93509’, ‘RB98710’, ‘SP791011’ and ‘SP921631’ and soil aggregate mean diam. > 0.48 mm, while root-zone densities were minimum in soils with P > 28.59 mg dm−3. This information should support further studies to investigate the effect of each variable on populations of Pratylenchus and Meloidogyne.

scholarly journals The effect of psychrotrophic bacteria isolated from the root zone of winter wheat on selected biotic and abiotic factors

2014 ◽  
Vol 54 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Sebastian Wojciech Przemieniecki ◽  
Tomasz Paweł Kurowski ◽  
Karol Korzekwa ◽  
Anna Karwowska
Keyword(s):  
Polymerase Chain Reaction ◽  
Winter Wheat ◽  
Root Zone ◽  
Abiotic Factors ◽  
Pathogenic Fungi ◽  
Growth And Yield ◽  
Chain Reaction ◽  
Psychrotrophic Bacteria ◽  
Rapd Pcr ◽  
Polymerase Chain

Abstract The roots of winter wheat plants, cv. Mikon, grown in 45-year monoculture, were analysed in the study. Twenty-two bacterial isolates obtained from the rhizosphere, rhizoplane, and endorhizosphere that were capable of growth at 8°C and at 28°C, were selected for further analysis. The isolated psychrotrophs accounted for 25% of all bacteria present in the wheat rhizosphere and capable of growth at 8°C. Psychrotrophic bacteria were analysed at a temperature of 10°C and 28°C to determine their ability to inhibit the growth of pathogenic fungi, solubilise mineral phosphates, and to determine their ability to degrade chitin and cellulose. Similarity between the isolates was determined by Enterobacterial Repetitive Intergenic Consensus – Polymerase Chain Reaction (ERIC-PCR) and Random Amplification of Polymorphic DNA – Polymerase Chain Reaction (RAPD-PCR). The majority of isolated psychrotrophs inhibited the growth of pathogenic fungi and solubilised mineral phosphates at both incubation temperatures. Psychrotrophic bacteria exerted a two-fold stronger inhibitory effect on mycelial growth at 10°C than at 28°C. The growth of Fusarium culmorum and F. oxysporum was inhibited to the highest extent at 10°C and at 28°C, respectively. Phosphate solubilisation rates were higher at 28°C, particularly in the rhizosphere. Regardless of temperature, the bacteria exhibited low chitin-degrading potential, and none of the isolates was capable of degrading cellulose. A high similarity between the selected psychrotrophs was revealed by ERIC-PCR and RAPD- -PCR analyses. Based on RAPD-PCR, the analysed population was divided into a group of isolates obtained from the rhizosphere, and two groups comprising representatives of both the rhizoplane and the endorhizosphere. Due to their ability to grow over a wide temperature range and increase phosphorus availability to plants, and their antagonism against pathogens, psychrotrophic bacteria can be used to improve the growth and yield of cereal crops.

scholarly journals First Report of Diaporthe australafricana Associated with Stem Canker on Blueberry in Chile

Plant Disease ◽  
2012 ◽  
Vol 96 (5) ◽  
pp. 768-768 ◽  
Author(s):  
B. A. Latorre ◽  
K. Elfar ◽  
J. G. Espinoza ◽  
R. Torres ◽  
G. A. Díaz
Keyword(s):  
Vitis Vinifera ◽  
Vascular Tissue ◽  
Its Region ◽  
Pathogenic Fungi ◽  
Stem Canker ◽  
Vaccinium Corymbosum ◽  
Academic Press ◽  
First Report ◽  
Potted Plants ◽  
Blastn Analysis

Stem cankers of blueberry (Vaccinium corymbosum L.) have been observed on as much as 15% of the plants in plantations in central and southern Chile since 2006. Symptoms consisted of apical necrosis of the shoots and brown-to-reddish necrotic lesions on the stems. Internally, a brown-to-reddish discoloration of the vascular tissue can be observed. Twenty, single-plant samples were collected in 12 blueberry plantings (approximately 33°27′ to 40°53′S). Isolations from the margins of the necrotic lesions on the stems were made by plating small pieces (5 mm) on potato dextrose agar acidified with 0.5 μl/ml of 92% lactic acid (APDA). The plates were incubated at 20°C for 5 to 7 days, and hyphal tips of white colonies with septate and hyaline mycelium were transferred to APDA. Colonies were then transferred to autoclaved Pinus radiata needles on 2% water agar and incubated for 20 days at 20°C. Twelve isolates producing black pycnidia and alpha conidia were tentatively identified as a Phomopsis sp. (teleomoph Diaporthe Nitschke). Other fungi, including Botryosphaeriaceae spp. and Pestalotiopsis spp., were also isolated. Alpha conidia were smooth, unicellular, hyaline, fusoid, biguttulate, and 6.4 to 7.9 × 2.3 to 3.3 μm (n = 20). Beta conidia were not observed. The internal transcribed spacer (ITS) region of the rDNA was amplified using primers ITS1 and ITS2 (4) and sequenced. BLASTn analysis of the 473-bp fragment (GenBank Accession No. JQ045712) showed 100% identity to Diaporthe australafricana Crous & J.M. van Niekerk from Vitis vinifera (3). The pathogenicity of D. australafricana was studied on blueberry cv. O'Neal using detached stems (n = 4) in the laboratory, on 2-year-old potted plants (n = 4) in a greenhouse, and on attached stems of mature plants (n = 4) established in the ground. Inoculations were done by placing mycelial plugs taken from 7-day-old APDA cultures in a 7-mm long incision made on the stems. Inoculations with sterile mycelium plugs served as negative controls. Inoculation sites were wrapped with Parafilm to avoid rapid dehydration. Dark brown, necrotic lesions on the internal tissues were obtained on all inoculated stems 15 days after inoculation. Mean lesion lengths were 18.0 ± 7.4 mm on detached stems, 7.8 ± 6.9 mm on stems of 2-year-old plants, and 7.3 ± 2.5 mm on mature plants in the field. No symptoms developed on control stems. Reisolations were successful in 100% of the inoculated stems and D. australafricana was confirmed by the presence of pycnidia and alpha conidia. To our knowledge, this is the first report of D. australafricana causing stem canker in V. corymbosum. Previously, this pathogen has been reported to be affecting Vitis vinifera in Australia and South Africa (3). These results do not exclude that other plant-pathogenic fungi may be involved in this syndrome (1,2). References: (1) J. G. Espinoza et al. Plant Dis 92:1407, 2008. (2) J. G. Espinoza et al. Plant Dis. 93:1187, 2009. (3) J. M. van Niekerk et al. Australas. Plant Pathol. 34:27, 2005. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, NY, 1990.

scholarly journals Efficient Propagation Technique of Euphorbia ×lomi Thai Hybrids

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 495-498 ◽  
Author(s):  
Giancarlo Fascella ◽  
Giovanvito Zizzo
Keyword(s):  
Acetic Acid ◽  
Root Zone ◽  
Naphthalene Acetic Acid ◽  
Rooted Cuttings ◽  
Potted Plants ◽  
Coir Dust ◽  
Mother Plants ◽  
Propagation Technique ◽  
Rooting Capacity

A simple and efficient in vivo propagation protocol of two cultivars of Euphorbia ×lomi Rauh is described. Mother plants of ‘Nguen Muang’ and ‘Porn Ying Yai’ were soilless grown in 1 coconut coir dust:1 perlite (by volume) and 2 sphagnum peat:1 perlite (by volume) to produce cuttings. Plants cultured in peat-based substrate showed thicker stems (36.0 versus 30.5 mm, respectively), higher production of cuttings (10.4 versus 5.6 per plant), higher water absorption (265.7 versus 153.5 mL/plant/d), and higher content of nutrients in the root zone as compared with those cultivated in coir dust mixture. Cuttings harvested from 1-year-old mother plants of both cultivars were treated with 4000 ppm of α-naphthalene acetic acid (NAA) powder and inserted into bottom-heated benches filled with different substrates [perlite, 1 perlite:1 coir dust (by volume), coir dust] for rooting. Cuttings in pure perlite evidenced higher rooting percentage (86.2%) and longer roots (6.2 cm) than those in other media. Application of NAA resulted in higher rooting capacity (78.8 versus 68.3%, respectively) and higher amount of roots per cutting (13.4 versus 10.2) than treatment without auxin. Rooted cuttings grown in 1 peat:1 perlite medium (by volume) produced higher marketable potted plants than in 2 peat:1 perlite medium.

scholarly journals Sürdürülebilir Bir Çevre İçin Biyopestisit Olarak Neem

2019 ◽  
Vol 7 (9) ◽  
pp. 1415
Author(s):  
Sadettin Ünsal
Keyword(s):  
Insect Pests ◽  
Pathogenic Fungi ◽  
Parasitic Nematodes ◽  
Botanical Pesticides ◽  
Living Things ◽  
Vector Management ◽  
Potential Applications ◽  
Regulatory Effects ◽  
Bacteria And Fungi ◽  
Neem Products

Pesticides have both acute and chronic effects on humans and all other warm blooded living things. In pesticide applications, few of the amount used reaches the target organisms, whereas the rest mixes into the ecosystem and leads to the deterioration of the ongoing natural balance. Therefore, growing attention has been given toward the development of alternate environmentally friendly pesticides/insecticides that would aid an efficient pest management system and also prevent chronic exposures leading to diseases. In this context, plant-derived natural products are considered valuable candidates to reverse this negative trend. Botanical pesticides are relatively safe, degradable, and are readily available sources of biopesticides. Neem is an ideal alternative candidate as a natural non-synthetic plant pesticide. The neem products have been obtained from several species of neem trees in the family Meliaceae. Array of more than 300 bioactive compounds in the neem tree makes it a unique plant with potential applications in pest and vector management. Botanical pesticides, such as neem, have limited persistence in the environment, and ultraviolet light, temperature, rainfall and other environmental factors can degrade neem. Unlike toxic synthetic insecticides, neem materials do not kill the pest, but incapacitate or neutralize it via cumulative behavioural, physiological, and cytological effects. In spite of high selectivity, neem materials affect more than 400 harmful species including insect pests, phytophagous mites, mites, and ticks affecting man and animals, parasitic protozoans, noxious molluscs, plant parasitic nematodes, pathogenic fungi, and harmful bacteria and fungi. Neem ingredients affect insects in various ways such as repellent, antifeedant, toxic, fecundity and growth regulatory effects. This review presents an overview of recent advances in research on the environmental impact of neem products and their use and effectiveness as a biopesticide.

Sign in / Sign up

Export Citation Format

Share Document