scholarly journals Persistence of Phytophthora ramorum in Soil Mix and Roots of Nursery Ornamentals

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1245-1249 ◽  
Author(s):  
Nina Shishkoff
Keyword(s):  
Infected Plant ◽  
Leaf Tissue ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Taxus Baccata ◽  
Acer Macrophyllum ◽  
Umbellularia Californica ◽  
Buxus Sempervirens ◽  
Significant Difference ◽  
Soil Mix

Although most Phytophthora species have a soilborne phase that is crucial for infection of roots and for survival away from the host, the details of the soil phase of Phytophthora ramorum are not yet fully understood. As mycelium ages, it becomes resistant to sterilization by acidic electrolyzed water (AEW), a product of the electrolysis which can be used as a disinfectant. Colonies of P. ramorum could be recovered from moist potting mix or sand for many months, whether buried as infected plant leaf tissue or as mycelium bearing chlamydospores, and the buried material was also resistant to treatment by AEW. There was no significant difference in recovery over time among treatments (sand or potting mix; infected plant tissue or mycelium); after approximately a year, colonies could be recovered at 0.8 to 14.3%. When excised roots were inoculated with P. ramorum sporangia and buried in mesh bags in potting mix, the pathogen was recovered from buried roots for at least 8 to 11 months, but it was not clear whether it was surviving as mycelium or chlamydospores. The roots of living plants of Acer macrophyllum, Buxus sempervirens, Camellia oleifera, C. sinensis, C. sasanqua, Lonicera hispidula, Taxus baccata, Umbellularia californica, Vaccinium macrocarpon, Viburnum davidii, V. tinus, V. × pragense, Rhododendron ‘Gloria’, and Syringa vulgaris were drenched with a sporangial solution of P. ramorum and incubated for a month; the pathogen could be recovered from roots of all plants except those of Buxus sempervirens and Lonicera hispidula. Recovery on selective agar medium (P5ARP) was from both washed and surface-sterilized roots, suggesting that the roots were internally infected. When chlamydospores were placed near roots and observed directly, they were seen to germinate, forming sporangia. Nearby roots became infected, the tips covered with sporangia. Therefore, P. ramorum appears to have a soil phase, at least under greenhouse and nursery conditions.

scholarly journals First Report of Phytophthora hydropathica Causing Wilting and Shoot Dieback on Viburnum in Italy

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1582-1582 ◽  
Author(s):  
S. Vitale ◽  
L. Luongo ◽  
M. Galli ◽  
A. Belisario
Keyword(s):  
Natural Infection ◽  
Morphological Characteristics ◽  
Leaf Tissue ◽  
The United States ◽  
Selective Medium ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Width Ratio ◽  
Morphological Identification ◽  
First Report

The genus Viburnum comprises over 150 species of shrubs and small trees such as Laurustinus (Viburnum tinus L.), which is one of the most widely used ornamental plants in private and public gardens. Furthermore, it commonly forms stands of natural woodland in the Mediterranean area. In autumn 2012, a survey was conducted to determine the presence of Phytophthora ramorum on Viburnum in commercial nurseries in the Latium region where wilting, dieback, and death of twigs were observed on 30% of the Laurustinus plants. A Phytophthora species was consistently recovered from soil rich in feeder roots from potted Laurustinus plants showing symptoms. Soil samples were baited with rhododendron leaves. Small pieces of leaf tissue cut from the margin of lesions were plated on P5ARPH selective medium (4). Pure cultures, obtained by single-hypha transfers on potato dextrose agar (PDA), were petaloid. Sporangia formation was induced on pepper seeds (3). Sporangia were almost spherical, ovoid or obpyriform, non-papillate and non-caducous, measuring 36.6 to 71.4 × 33.4 to 48.3 μm (average 53.3 × 37.4 μm) with a length/width ratio of 1.4. Chlamydospores were terminal and 25.2 to 37.9 μm in diameter. Isolates were considered heterothallic because they did not produce gametangia in culture or on the host. All isolates examined had 30 to 35°C as optimum temperatures. Based on these morphological characteristics, the isolates were identified as Phytophthora hydropathica (2). Morphological identification was confirmed by internal transcribed spacer (ITS), and mitochondrial partial cytochrome oxidase subunit 2 (CoxII) with BLAST analysis in the NCBI database revealing 99% identity with ITS and 100% identity with CoxII. The sequences of the three isolates AB234, AB235, and AB236 were deposited in European Nucleotide Archive (ENA) with the accession nos. HG934148, HG934149, and HG934150 for ITS and HG934151, HG934152, and HG934153 for CoxII, respectively. Pathogenicity tests were conducted in the greenhouse on a total of six 1-year-old shoots cut from V. tinus plants with two inoculation points each. Mycelial plugs cut from the margins of actively growing 8-day-old cultures on PDA were inserted through the epidermis into the phloem. Controls were treated as described above except that sterile PDA plugs replaced the inoculum. Shoots were incubated in test tubes with sterile water in the dark at 24 ± 2°C. After 2 weeks, lesions were evident at the inoculation points and symptoms were similar to those caused by natural infection. P. hydropathica was consistently re-isolated from the margin of lesions, while controls remained symptomless. In the United States in 2008, P. hydropathica was described as spreading from irrigation water to Rhododendron catawbiense and Kalmia latifolia (2). This pathogen can also attack several other horticultural crops (1), but to our knowledge, this is the first report of P. hydropathica causing wilting and shoot dieback on V. tinus. References: (1) C. X. Hong et al. Plant Dis. 92:1201, 2008. (2) C. X. Hong et al. Plant Pathol. 59:913, 2010. (3) E. Ilieva et al. Eur. J. Plant Path. 101:623, 1995. (4) S. N. Jeffers and S. B. Martin. Plant Dis. 70:1038, 1986.

scholarly journals Phytophthora ramorum and Phytophthora gonapodyides Differently Colonize and Contribute to the Decomposition of Green and Senesced Umbellularia californica Leaves in a Simulated Stream Environment

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 434
Author(s):  
Kamyar Aram ◽  
David M. Rizzo
Keyword(s):  
Surface Waters ◽  
Aquatic Ecosystems ◽  
Litter Quality ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Controlled Environment ◽  
Green Leaves ◽  
Umbellularia Californica ◽  
And Function ◽  
Forest Streams

Plant pathogenic as well as saprotrophic Phytophthora species are now known to inhabit forest streams and other surface waters. How they survive and function in aquatic ecosystems, however, remains largely uninvestigated. Phytophthora ramorum, an invasive pathogen in California forests, regularly occurs in forest streams, where it can colonize green leaves shed in the stream but is quickly and largely succeeded by saprotrophically competent clade 6 Phytophthora species, such as Phytophthora gonapodyides. We investigated, using controlled environment experiments, whether leaf litter quality, based on senescence, affects how P. ramorum and P. gonapodyides compete in leaf colonization and to what extent each species can contribute to leaf decomposition. We found that both Phytophthora species effectively colonized and persisted on green or yellow (senescing) bay leaves, but only P. gonapodyides could also colonize and persist on brown (fully senesced and dried) leaves. Both Phytophthora species similarly accelerated the decomposition of green leaves and yellow leaves compared with non-inoculated controls, but colonization of brown leaves by P. gonapodyides did not affect their decomposition rate.

scholarly journals First Report of Phytophthora ramorum on Rhododendron in Greece

Plant Disease ◽  
2011 ◽  
Vol 95 (2) ◽  
pp. 223-223 ◽  
Author(s):  
P. Tsopelas ◽  
E. J. Paplomatas ◽  
S. E. Tjamos ◽  
N. Soulioti ◽  
K. Elena
Keyword(s):  
Plant Species ◽  
Infected Plant ◽  
Weather Conditions ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Maximum Temperature ◽  
Width Ratio ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Adverse Weather

In April 2010, during a survey conducted in Fthiotis Prefecture of central Greece, symptoms of stem necrosis and leaf lesions were observed on two container-grown plants of Rhododendron, hybrid ‘Kate Waterer' in a nursery. From symptomatic leaves, a Phytophthora species was isolated on PARPH-V8 selective agar medium (2) with typical morphological characters of Phytophthora ramorum S. Werres & A.W.A.M. de Cock (4). The whole block of plants was under probation until molecular verification of the pathogen was completed. The nursery was reexamined 6 weeks after the first encounter, whereas spread of the pathogen was noticed to neighboring plants in the same block; five more Rhododendron plants with similar symptoms were recorded while one of the originally infected plants was dead. Isolates of Phytophthora with similar morphology were obtained from symptomatic leaves of three new plants as well as from the potting mix of a severely infected plant that was baited in a Rhododendron leaf assay (2). All Rhododendron plants in the block belonged to the same consignment imported from Belgium and covered by a phytosanitary plant passport. Colonies on 10% clarified V8 juice agar appeared with coralloid, coenocytic mycelium with radial growth at 1.7 mm per day at 20°C and maximum temperature 26 to 27°C. Propagules characteristic of P. ramorum, including semipapillate, caducous, sporangia measuring 35 to 55 × 15 to 30 μm (1.9 length/width ratio) and large chlamydospores (45 to 80 μm), were observed on V8 agar. One isolate was confirmed as P. ramorum by sequence analysis of the internal transcribed spacer region of rDNA and was deposited in the culture collection of the University of Athens (ATHUM 6522). Comparison of amplicon sequences (using ITS4/5 primer pair) of approximately 875 bp long was carried out using MEGABLAST search for highly similar sequences. Alignment data revealed the highest and most significant homology to P. ramorum (GenBank Accession No. AY594198.1) at 99%. Pathogenicity tests were carried out using detached leaves of Rhododendron hybrid ‘Red Jack’ and Arbutus unedo L., which were slightly wounded and inoculated with mycelium agar plugs (3). Necrotic lesions appeared on the inoculated leaves of both plant species 10 days after incubation at 20°C, while no symptoms developed on control leaves inoculated with sterile agar plugs. P. ramorum was consistently reisolated from artificially infected leaves of both plant species. Following confirmation of pathogen presence, eradication measures were applied in the nursery. The adverse weather conditions encountered in summer, with temperatures very often above 35°C, are expected to favor pathogen eradication. However, not all plants of the same consignment imported from Belgium were traced and it is possible that other infected plants have been sold in other areas of Greece. So far, P. ramorum had been reported in 21 other European countries; Serbia is the nearest country where the pathogen was detected (1). To our knowledge, this is the first report of P. ramorum in Greece. References: (1) A. Bulajić et al. Plant Dis. 94:703, 2010. (2) E. J. Fichtner et al. Phytopathology 97:1366, 2007. (3) R. G. Linderman et al Online publication. doi:10.1094/PHP-2007-0917-01-RS. Plant Health Progress, 2007. (4) S. Werres et al. Mycol. Res. 105:1155, 2001.

scholarly journals Phytophthora Leaf Spot and Foliar Blight of Pieris japonica Caused by Phytophthora citricola in California

Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 1013-1013 ◽  
Author(s):  
S. T. Koike ◽  
G. T. Browne ◽  
R. G. Bhat ◽  
R. C. M. Lee ◽  
S. A. Tjosvold ◽  
...  
Keyword(s):  
Leaf Tissue ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Foliar Disease ◽  
Leaf Petiole ◽  
Foliar Blight ◽  
Leaf Spots ◽  
Agar Plug ◽  
Advanced Stages ◽  
Symptomatic Leaf

During 2004, containerized nursery stock of lily-of-the-valley-bush (Pieris japonica ‘Flamingo’, family Ericaceae) in Santa Cruz County was affected by a foliar disease. Symptoms consisted of large leaf spots, many developing at the leaf tips that ranged in size from 1 to greater than 4 cm in diameter. Spots were dark brown to almost black, generally oval to round, visible from both sides of the leaf, and did not exhibit signs of any pathogen. Lesions typically expanded and affected the entire leaf, leaf petiole, and stems, resulting in blight-like symptoms. Severely affected leaves abscised from the plant. In advanced stages of the disease, the foliage of the plant was killed. These symptoms resembled those caused by the sudden oak death (SOD) pathogen, Phytophthora ramorum (3). A Phytophthora sp. was isolated consistently from symptomatic leaf tissue. However, the species was identified as P. citricola based on morphological traits that included the following: production of semipapillate, noncaducous sporangia that were irregular in shape and occasionally had more than one apex; presence of oospores with paragynous antheridia in single culture; and radiate to slightly petaloid colony morphology (1). P. ramorum and other fungi were not recovered. Pathogenicity of four representative isolates was confirmed by gently abrading the adaxial surfaces of attached leaves with a sterile wire brush, placing a colonized agar plug (5 mm in diameter) on the surface, misting the leaf with sterile water, and then covering the plug with a plastic cap that was secured with a wire clip. Control leaves were treated in the same manner but received sterile agar plugs. Plants were maintained in a greenhouse at 23 to 25°C. After 2 days, all leaves inoculated with the isolates exhibited dark brown lesions and by day 6, lesions measured 3 cm in diameter. P. citricola was reisolated from symptomatic lesions. Sterile plug control leaves developed no symptoms. The test was repeated and the results were similar. To our knowledge, this is the first report of P. citricola causing a foliar disease of Pieris japonica in California. P. citricola has been reported as a pathogen on Pieris spp. in Ohio (2). Our finding is important because P. ramorum causes very similar symptoms on this same host (3). The occurrence of these two foliar Phytophthora spp. on this ornamental plant may complicate P. ramorum field detection during inspections and laboratory confirmations as established by quarantine regulations. References: (1) D. C. Erwin and O. K. Ribeiro. Morphology and Identification of Phytophthora Species. Pages 96–144 in: Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) W. W. P. Gerlach et al. Phytopathology 64:1368, 1974. (3) P. W. Tooley et al. Plant Dis. 88:993, 2004.

The effect of applied salinity and water stress on chemical suppression of Phytophthora ramorum from soilborne inoculum in Rhododendron

Plant Disease ◽  
2021 ◽  
Author(s):  
Richard M. Bostock ◽  
Tatiana V Roubtsova
Keyword(s):  
Water Stress ◽  
Abiotic Stresses ◽  
Root Colonization ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Plant Interactions ◽  
Foliar Symptoms ◽  
Series Of Experiments ◽  
Pathogen Colonization ◽  
Soil Mix

A serious concern for nurseries is the potential for Phytophthora ramorum and other Phytophthora species to colonize roots without inducing aboveground symptoms in plants that then serve as cryptic reservoirs of inoculum. Episodic abiotic stresses that reduce plant water potential can compromise host resistance to trigger disease development from root and crown infections in many Phytophthora-plant interactions. We conducted a series of experiments with root-inoculated Rhododendron plants in a potting soil mix to assess influence of excess salt or water deficit on ramorum blight development and the potential for these abiotic stresses to affect efficacy of oomycete-suppressive chemical soil treatments. In growth chamber trials, P. ramorum colonized roots in both non-salted and salt-treated plants. However, salt treatment offset the benefit realized from soil treatment with mefanoxam (Subdue Maxx) or mandipropamid (Micora), as evidenced by enhanced pathogen colonization of roots. A three-week episode of water stress imposed after chemical treatment but prior to inoculation eliminated protection against P. ramorum root colonization conferred by fosetyl-Al (Aliette). In an outdoor experimental nursery, foliar symptoms were apparent in 23% of root-inoculated plants in two trials and absent in one trial. However, the majority of inoculated plants in all trials had colonized roots with little or no aboveground symptoms. A single application of Subdue Maxx or Aliette reduced root colonization by P. ramorum in Rhododendron plants. Although salt stress did not enhance ramorum blight symptom expression in the nursery, salt partially offset protection from P. ramorum root colonization obtained by Subdue Maxx.

scholarly journals First Detection of Phytophthora ramorum Mating Type A2 in Europe

Plant Disease ◽  
2003 ◽  
Vol 87 (10) ◽  
pp. 1266-1266 ◽  
Author(s):  
Sabine Werres ◽  
Daphné De Merlier
Keyword(s):  
United States ◽  
The Netherlands ◽  
Mating Type ◽  
The United States ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Taxus Baccata ◽  
Camellia Japonica ◽  
Wide Range

Since its original isolation in 1993, Phytophthora ramorum has become an important pathogen. Initially, it was determined to be the causal agent of a twig blight of Rhododendron spp. in Germany and the Netherlands (3). Around the same period, symptoms and mortality on oak (Quercus spp.) and tanoak (Lithocarpus densiflorus) were associated with P. ramorum in California (2), where the disease was named sudden oak death. Subsequently, P. ramorum has been detected on a wide range of forest trees and shrub species in the United States. In Europe, the pathogen has spread to many countries, primarily on nursery plants of Rhododendron and Viburnum spp., and recently, on Camellia japonica, Kalmia latifolia, Pieris formosa var. forrestii, P. japonica, Leucothoe sp., Syringa vulgaris, and Taxus baccata. P. ramorum has not been observed in European forests. P. ramorum is heterothallic, and initial in vitro mating studies on agar media suggested that only the A1 mating type occurred in Europe, while only the A2 mating type was present in the United States (4). However, an isolate collected in 2002 in Belgium (1) appears to be the A2 mating type. This isolate (CBS 110901, Centraal Bureau voor Schimmelcultures, Baarn, the Netherlands) originated from an imported V. bodnantense plant at an ornamental nursery. A hyphal tip culture (BBA 26/02) of this isolate produced no oogonia on carrot piece agar after 6 weeks in pairing tests with other Phytophthora species of mating type A2. When paired with mating type A1 of P. cambivora, P. cinnamomi, P. cryptogea, and P. drechsleri, however, oogonia were observed in all pairings within 6 weeks. The number of oogonia was low in all pairings but was highest in pairings with P. cryptogea. No oospores were produced after 6 weeks between P. ramorum isolates BBA 26/02 and BBA 9/95 (from the holotype, mating type A1), but gametangia were observed when these isolates were paired on Rhododendron sp. twigs. Normal oogonia were produced on the outgrowing mycelium when pieces from these twigs were placed on carrot piece agar. The shape and size of the oogonia produced on carrot piece agar after pairing with P. cryptogea and on Rhododendron sp. twigs after pairing with P. ramorum BBA 9/95 were similar (24 to 34 μm, mean 29.6 μm and 25 to 33 μm, mean 30.6 μm, respectively). To our knowledge, this is the first observation of P. ramorum mating type A2 in Europe. References: (1) D. De Merlier et al. Plant Dis. 87:203, 2003. (2) D. M. Rizzo et al. Plant Dis. 86:205, 2002. (3) S. Werres et al. Mycol. Res. 105:1166, 2001. (4) S. Werres and B. Zielke. J. Plant Dis. Prot. 110:129, 2003.

scholarly journals First Report of Phytophthora ramorum on Viburnum bodnantense in Belgium

Plant Disease ◽  
2003 ◽  
Vol 87 (2) ◽  
pp. 203-203 ◽  
Author(s):  
D. De Merlier ◽  
A. Chandelier ◽  
M. Cavelier
Keyword(s):  
The Netherlands ◽  
Plant Protection ◽  
Morphological Characteristics ◽  
Pcr Primers ◽  
Selective Medium ◽  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Pathogenicity Test ◽  
First Report ◽  
Root Necrosis

In the past decade, a new Phytophthora species inducing shoot canker on Rhododendron and dieback of Viburnum has been observed in Europe, mainly in Germany and the Netherlands, and California. This new pathogen has been named Phytophthora ramorum (3). In May 2002, a diseased Viburnum plant (Viburnum bodnantense) from the Plant Protection Service (Ministry of Agriculture, Belgium) was submitted to our laboratory for diagnosis. Symptoms included wilting, leaves turning from green to brown, discolored vascular tissues, and root necrosis. The plant came from a Belgian ornamental nursery that obtained supplies of stock plants from the Netherlands. Pieces of necrotic root tissue were excised, surface-disinfected, and transferred aseptically to a Phytophthora selective medium. P. ramorum was identified based on morphological characteristics, including the production of numerous, thin-walled chlamydospores (25 to 70 µm in diameter, average 43 µm) and deciduous, semi-papillate sporangia arranged in clusters. Radial growth after 6 days at 20°C on V8 juice agar was 2.8 mm per day. Random amplified microsatellite markers (RAMS) (2) from the total genomic DNA of the Belgian strain (CBS 110901) were similar to those of P. ramorum reference strains (CBS 101330, CBS 101332, and CBS 101554). Using PCR primers specific for P. ramorum, the identification was confirmed by W. A. Man in't Veld (Plantenziektenkundige Dienst, Wageningen, the Netherlands) (1). A pathogenicity test was carried out on three sterile cuttings of Rhododendron catawbiense (3). Brown lesions were observed on the inoculated cuttings after 6 to 7 days. None of the three uninoculated cuttings showed symptoms of infection. P. ramorum was reisolated from lesion margins on the inoculated cuttings. To our knowledge, this is the first report of the fungus from Belgium. Since our initial observation, we have found P. ramorum in other Belgian nurseries on R. yakusimanum. References: (1) M. Garbelotto et al. US For. Ser. Gen. Tech. Rep. PSW-GRT. 184:765, 2002. (2) J. Hantula et al. Mycol. Res. 101:565, 1997. (3) S. Werres et al. Mycol. Res. 105:1155, 2001.

scholarly journals Occurrence of Phytophthora Species in Commercial Nursery Production

2016 ◽  
Vol 17 (2) ◽  
pp. 64-75 ◽  
Author(s):  
Corina Junker ◽  
Patrick Goff ◽  
Stefan Wagner ◽  
Sabine Werres
Keyword(s):  
Phytophthora Species ◽  
Phytophthora Ramorum ◽  
Water Recycling ◽  
Infection Rates ◽  
Sand Filter ◽  
Detection Rates ◽  
Water And Sediment ◽  
Nursery Production ◽  
Slow Sand Filter ◽  
Soil Substrates

Two commercial woody ornamental nurseries were sampled for the presence of Phytophthora species over a period of three years between 2011 and 2014. The samples were taken every two months at different propagation (greenhouses, plastic tunnels) and cultivation (container stands) areas as well as from nearby pathways and from a water recycling system with a slow sand filter. Furthermore, different materials like soil, substrates, residues, wind-carried leaves, water and sediment were sampled. In total, 12 known Phytophthora species could be detected. Further, three isolates did not match any of the known species. Phytophthora ramorum, P. gonapodyides, and P. plurivora were the species with the highest detection rates. Phytophthora ramorum could be detected during all seasons of the year. In total, the puddles on the pathways had the highest percentage of positive detections. Residues, wind-carried leaves and water and sediment from the water runoffs were also good places for Phytophthora survival. In both nurseries, the plant samples showed very low infection rates. Ideas for surveys and management are discussed. Accepted for publication 14 March 2016. Published 11 April 2016.

scholarly journals The Effects of Endophytic Beauveria bassiana Inoculation on Infestation Level of Planococcus ficus, Growth and Volatile Constituents of Potted Greenhouse Grapevine (Vitis vinifera L.)

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 72 ◽  
Author(s):  
Siphokazi Moloinyane ◽  
Felix Nchu
Keyword(s):  
Beauveria Bassiana ◽  
Insect Pests ◽  
Growth Parameters ◽  
Leaf Tissue ◽  
Gas Chromatography Mass Spectrometry ◽  
Vitis Vinifera L ◽  
Infestation Level ◽  
Volatile Constituents ◽  
Nutrient Contents ◽  
Significant Difference

Endophytic entomopathogenic fungi are being explored for the management of phytophagous insect pests. The effects of Beauveria bassiana (Hypocreales) inoculation of grape plants on the infestation level of P. ficus, tissue nutrient contents, and growth and volatile constituents of potted grape plants were assessed. Grapevine plants were individually inoculated with a suspension of 1 × 108 conidia mL−1 of B. bassiana by drenching before experimentally infesting each of them with thirty adult females of P. ficus. At four weeks post-treatment, the fungus was re-isolated from leaves of 50% of the fungus-exposed plants. However, no significant difference (p > 0.05) was observed in all the plant growth parameters measured in the fungus-treated and control plants. Plant tissue analysis revealed markedly higher contents of calcium (Ca) and magnesium (Mg) in the leaf tissue of plants exposed to the B. bassiana relative to the control. Gas chromatography mass spectrometry (GC-MS) analyses showed that a significantly (X2 = 5.1; p < 0.02) higher number of known anti-insect volatile compounds (nine) were present among fungus treated plants compared to the control plants (five). Naphthalene, which is toxic to insects and humans, was detected only in the volatiles of the fungus-exposed plants. B. bassiana did not have any significant effect on total polyphenol, alkaloid, and flavonoids. Overall, treatment with fungus did not inhibit the infestation by P. ficus. In conclusion, these findings shed light on some of the mechanisms involved in endophytic fungus-plant-insect interactions.

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