Dactylaria Brochopaga Research Articles

Drechslerella dactyloides and Dactylaria brochopaga mediated structural defense in tomato plants pre-challenged with Meloidogyne incognita

The present study was undertaken with the objectives to study Drechslerella dactyloides NDAd-05 and Dactylaria brochopaga NDDb-15 mediated induction of structural defense responses leading to lower disease development and promoting growth in tomato pre-challenged with Meloidogyne incognita. The potential strains D. dactyloides NDAd-05 and D. brochopaga NDDb-15 were taken from Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan, India. In vitro root colonization assay was performed using D. dactyloides NDAd-05 and D. brochopaga NDDb-15 in sand:soil culture (2:1) and significant tomato root colonization by NDAd-05 and NDDb-15 was recorded. The study elucidated multifarious effects of D. dactyloides NDAd-05 and D. brochopaga NDDb-15 when inoculated either individually or in combination in tomato plants pre-challenged with M. incognita. Additionally, D. dactyloides NDAd-05 and D. brochopaga NDDb-15 increased antioxidant as well as biocontrol activities significantly in tomato against M. incognita. Microscopic visualization of H2O2 and superoxide radicals in tomato leaves further corroborated the above findings. Further, inoculation of D. dactyloides NDAd-05 and D. brochopaga NDDb-15 activated the phenylpropanoid pathway in roots leading to increase cell wall lignifications and pectin deposition in tomato roots in addition to direct trapping and parasitizing of juveniles and adults of M. incognita. From the results it can be concluded that increased cell wall lignifications and pectin deposition probably restricted the entry of nematodes and ultimately decreased the M. incognita population in tomato roots. It was also observed that plants treated with bioagents individually or in combination modulated the phenotypical alterations and assisted plant growth promotion. This might be due to the interaction-dependent modulation of physio-biochemical pathways in the tomato plants which ultimately reduced the inoculum potential and disease intensity of M. incognita.

Drechslerella dactyloides and Dactylaria brochopaga mediated induction of defense related mediator molecules in tomato plants pre-challenged with Meloidogyne incognita

The present investigation was aimed to isolate and characterize the strains of Drechslerella dactyloides and Dactylaria brochopaga from decaying root galls of tomato in order to investigate their role in reprogramming of root apoplast that enhance defence responses in tomato pre-challenged with Meloidogyne incognita. Out of 23 strains of D. brochopaga and D. dactyloides were isolated from decaying root galls of tomato, three strains of D. dactyloides and five strains of D. brochopaga were found effective and these were selected for further characterization under controlled laboratory conditions. Further, D. dactyloides NDAd-05 and D. brochopaga NDDb-15 were found most promising strains for control of M. incognita. The study elucidates multifarious effects of D. dactyloides NDAd-05 and D. brochopaga NDDb-15 inoculated either individually or in combination on tomato plants pre-challenged with M. incognita under nethouse conditions. Results of this investigation revealed that inoculation of D. dactyloides NDAd-05 and D. brochopaga NDDb-15 increased various attributes in plants to significant degree conferring defence against M. incognita. Both the strains were found to have potential to enhance site-specific accumulation and activation of defence-related mediator molecules, enzymes and thus, exhibited biocontrol potential against M. incognita. Further, application of D. dactyloides NDAd-05 and D. brochopaga NDDb-15 not only assisted in the growth promotion but also activated phenylpropanoid pathway in root apoplast in addition to direct trapping of M. incognita.

Effect of the Nematode-Trapping Fungus Dactylaria Brochopaga and the Nematode Egg Parasitic Fungus Verticilium Chlamydosporium in Controlling Citrus Nematode Infesting Mandarin, And Interrelationship with the Co Inhabitant Fungi

In a field experiment, the nematode-trapping fungus Dactylaria brochopaga and the nematode egg parasitic fungus Verticilium chlamydosporium , was evaluated against the citrus nematode, Tylenchulus semipenetrans infesting Mandarin, Citrus reticulata, , the mixed compound was applied in October 2016 at the rate ½ kg/tree, and root and soil samples were collected monthly until the next October, 2017. Successive treatment of the same mixed compound was added in the end of April 2017. For the comparison, Vydate 24% L. was applied as well as non treated check trees were left. Data revealed that the mixed compound treatment greatly affected the citrus nematode numbers both in soil and roots, in comparing with those of Vydate or induced by mixed compound was 97% and 70%; respectively in soil and roots. Rates of reproduction increase of the citrus nematode also reached 3% and 30% in both soil and roots; respectively. Vydate treatment resulted in a relatively lesser percentages. Growth of the concomitant fungus, Trichoderma sp. was increased specially in the last samples of October 2017, however those of fungi; Aspergillus flavus, Fusarium sp. And Rhizopus sp. was reduced, due to mixed compound treatment. Aspergillus niger and Penicillium sp. were not affected by the presence of the mixed compound. Vydate did not affect the co inhabitant fungi to a great extent.

Studies of Aquatic Fungi XXVIII The presence of predatory fungi in the waters of north-eastern Poland

The work was undertaken to investigate the predatory fungi in the waters of north-eastern Poland. The following predatory fungi were found: <i>Sommerstorffia spinosa, Zoophagus insidians, Z. pectosporus, Z. tentaculum, Zoopage phanera, Arthrobotrys oligospora</i> and <i>Dactylaria brochopaga</i>.

Nematophagous fungi: Catenaria anguillulae and Dactylaria brochopaga from seed galls as potential biocontrol agents of Anguina tritici and Meloidogyne graminicola in wheat (Triticum aestivum L.)

During the course of our investigation on the selective isolation and in vitro pathogenicity tests of the nematode egg parasite and endoparasitic Catenaria anguillulae and the nematode-trapping fungus Dactylaria brochopaga against Anguina tritici, and Meloidogyne graminicola, the two biocontrol agents were also examined for their capabilities to colonize wheat seed gall and also to reduce the M. graminicola, and A. tritici in wheat (Triticum aestivum L.). Using seed galls as bait was found effective for isolating the soilborne natural colonizers of seed galls of wheat caused by A. tritici. Seed galls were found severely infested with cellulose decomposers as well as nematode trapping fungi i.e., Fusarium spp., Verticillium spp., Aspergillus spp., Penicillium spp. Arthrobotrys oligospora, Arthrobotrys superba, Arthrobotrys dactyloides, Arthrobotrys musiformis, D. brochopaga, Monacrosporium eudermatum, Stylopaga hadra, Paecilomyces spp., and C. anguillulae. Co-inoculation of D. brochopaga DBS-105, and C. anguillulae CAS101 significantly reduced the root knot and seed gall in wheat and increased the plant growth parameters including length, and dry weight of root and shoot as well as yield attributing characters like spike length; number of seed per spike, test weight etc. under greenhouse conditions as compared to pathogen challenged plants without any bioagents/chemical nematicide. These bioagents have the potential to enhance production of quality seeds of wheat being free from hazardous pesticides and thus, can further be developed into marketable formulations in order to promote eco-friendly and sustainable means of crop production.

Biological control of root-knot nematode Meloidogyne incognita infesting cucumber Cucumis sativus L. cvs. Alfa by the nematode-trapping fungus Dactylaria brochopaga under field conditions

Microbial control of root-knot nematode Meloidogyne incognita infesting cucumber Cucumis sativus L. cvs. Alfa by using the nematode-trapping fungus Dactylaria brochopaga Drechsler, 1937 alone or mixed with yeast or molasses is reported under an open field experiment. The data revealed that the nematode-trapping fungus D. brochopaga alone or in combination with yeast, molasses and vermiculite reduced the juvenile-Meloidogyne incognita-population density per one kg soil and number of root-galls per one gm roots. Weight of cucumber fruits per plant was significantly (P≤0.05 and/or P≤ 0.01) increased in each fungus treatment compared to the untreated diseased check.

Co-inoculation of Dactylaria brochopaga and Monacrosporium eudermatum affects disease dynamics and biochemical responses in tomato (Lycopersicon esculentum Mill.) to enhance bio-protection against Meloidogyne incognita

The nematode trapping ability of nematophagous fungi Dactylaria brochopaga and Monacrosporium eudermatum to colonize tomato root and parasitize and kill root-knot nematode Meloidogyne incognita was evaluated, along with the capability of the fungi to induce the accumulation of defence-related biomolecules in tomato plants under the greenhouse and field conditions. Co-inoculation of D. brochopaga Dp-5 and M. eudermatum Mv-1 significantly reduced root-knot disease in tomato (89.63%) and increased the accumulation of total chlorophyll (125.34, 140.53 and 152.67 mg g−1 fresh wt.), total phenolic compounds (TPC) (37.40, 48.32 and 59.63 μg of gallic acid equivalent), and phenylalanine ammonia lyase (PAL) activity (58.45, 69.05 and 74.57 mM cinnamic acid h−1 g−1 fresh wt.) after 10, 20 and 30 days of inoculation, respectively, in the greenhouse. However, in the field experiments, the total chlorophyll content in leaves of M. incognita infected tomato plants co-inoculated with D. brochopaga Dp-5 and M. eudermatum Mv-1 (152.70 mg g−1 fresh wt.) was higher than the plants treated with D. brochopaga Dp-5 or M. eudermatum Mv-1 individually (130.87 and 144.73 mg g−1 fresh wt., respectively) and M. incognita treated plants (19.47 mg g−1 fresh wt.). TPC and PAL activity were found to be higher in tomato leaves co-inoculated with D. brochopaga Dp-5 and M. eudermatum Mv-1 (62.90 μg of gallic acid equivalent and 79.33 mM cinnamic acid h−1 g−1 fresh wt., respectively) than the plants treated with D. brochopaga Dp-5 or M. eudermatum Mv-1 individually, whereas in M. incognita inoculated and control plants, the induction of these two compounds was found to be very low after 30 days of inoculation. The results of this study showed that these fungi reduced root-knot disease and enhanced accumulation of defence related biomolecules in tomato plants and has potential to serve as a biocontrol agents against root-knot nematodes.

The trapping fungus Dactylaria Brochopaga: induction of trap formation, attraction, trapping and the development in some phytonematodes

All the six species of the phytonematodes induced traps directly on the spores of all the five isolates of Dactylaria brochopaga. The maximum rings induction was observed in the presence of second-stage juveniles of Meloidogyne incognita followed by Meloidogyne graminicola (J2), Xiphinema basiri, Helicotylenchus dihystera, Tylenchorynchus brassicae and Hoplolaimus indicus. Maximum number of induced traps was recorded at temperature 28°C (98.3%) and pH 7 (96.7%) in the presence of H. indicus. In attraction assay, irrespective of the isolates of the fungus, all the six phytonematodes were attracted towards the fungal discs of the different isolates of D. brochopaga. Among all the five isolates, Isolate D attracted maximum (34.7%) number of nematodes closely followed by Isolate C (31.0%), whereas, Isolate A, B and E did not differ significantly. Maximum in vitro trapping was recorded in the case of M. incognita (J2) followed by M. graminicola (J2), H. dihystera and T. brassicae. The maximum ringing (pre-capturing), trapping and killing was recorded for the second-stage juveniles of M. incognita followed by M. graminicola, T. brassicae and H. dihystera. The inflation of ring cells did not occur immediately after ringing; however, the time between ringing and inflation varied with different nematodes species. Clear hyphae were observed in the invaded nematodes body after the content of nematode body was consumed. External growth of hyphae occurred only from the inflated cells of the constricting rings, which further developed several rings. Higher number of rings was observed in mycelia developed from bigger nematodes.

Occurrence and colonization of nematophagous fungi in different substrates, agricultural soils and root galls

Seventeen species of nematophagous fungi were recorded, three species were endoparasitic and fourteen species were predacious fungi. Among the predacious fungi Arthrobotrys oligospora, Dactylaria brochopaga and Monacrosporium eudermatum were very frequent, whereas others were recorded at lower frequency. Twelve species of nematophagous fungi from compost as well as cow dung manure, 15 species from leaf litter and only eight species from agricultural soils were recorded. In general, substrate colonization by nematophagous fungi was higher in leaf litter, compost and cow dung manure. The agricultural soil amended with FYM (farm yard manure) recorded nine species of nematophagous fungi while unamended soil recorded only seven species. Thirteen species of nematophagous fungi were recorded from soils under banyan tree. Of all these fungi unidentified net-forming fungus, M. eudermatum, A. cladodes, D. brochopaga, S. hadra, A. oligospora and A. dactyloides had higher percentage of soil colonization. In soil collected under pipal tree only eight species were recorded, of which A. oligospora, A. cladode and an unidentified fungus were more predominant as their percentage colonized in soil samples was higher. Few studies have examined root galls as a substratum for colonization of nematophagous fungi. Of all the root gall samples, okra root galls recorded maximum colonization by predacious fungi. Maximum percentage of root gall colonization was recorded for M. eudermatum followed by A. oligospora and M. ellipsosporum. M. eudermatum was also most predominant colonizer of balsam, brinjal and rice root galls.

Use of Dactylaria brochopaga, a Predacious Fungus, for Managing Root-Knot Disease of Wheat (Triticum aestivum) Caused by Meloidogyne graminicola

A laboratory experiment was conducted to study the induction of constricting rings and test predation of Dactylaria brochopaga isolates against second stage juveniles (J2s) of Meloidogyne graminicola. Among the five fungal isolates, isolate D showed the greatest number of predatory rings and, consequently, trapped the maximum number of M. graminicola J2s in dual cultures. Another pot experiment was conducted to study the effect of D. brochopaga (isolate D) on the management of wheat root-knot disease. Applying a mass culture (10 g/pot) and a spore suspension of the fungus with and without cow dung manure to soil infested with 2,000 M. graminicola juveniles significantly improved plant height, root length, weights of shoots, roots, panicles and grains per hill compared to those in the control. Moreover, the fungus significantly reduced the number of root-knots, the number of egg masses, juveniles, and females per hill compared to those in the control. Bioefficacy of the fungus was heightened when the mass culture and a spore suspensions were used in combination with cow dung manure to improve the plant growth parameters and reduce the number of root-knot and reproductive factors. Further investigations should be conducted to identify the impact of this fungus in the field.

Population density of Meloidogyne incognita on sunflower as affected by certain organic composts under field conditions

The effect of three composts viz., pigeon, sheep and cattle applied at three different times were studied under field conditions .These composts were applied as soil amendments for control of Meloidogne incognita at the rates of 2,4 and 8 tons/ feddan to sunflower cv. Euroflower 40 days after decomposition before planting (season, 2006), at planting time (season, 2007) or left for a week to allow decomposition before planting (season 2008). All the tested materials significantly (p ≤ 0.05 / 0.01) reduced the number of galls, egg masses and second stage larvae in soil as compared to untreated check and increased the weight of flowering discs, specially, dose 4 tons per feddan at three season 2006, 2007 and 2008, respectively. Composts application inhibit pathogenic fungi as Pythium sp. and Alternaria sp. growth and increased number of beneficial fungi as Trichoderma harzianum, Arthrobotrys conoides and Dactylaria brochopaga.

Combination of the entomopathogenic nematode Heterorhabditis bacteriophora and the nematode-trapping fungi Dactylaria brochopaga and Arthrobotrys conoides for controlling Meloidogyne incognita in tomato fields

Effects of combining an entomopathogenic nematode (EPNs) and nematode-trapping fungi to control root-knot nematode were studied in the laboratory and in a tomato field. Bioassay effects of EPNs (Heterorhabditis bacteriophora) on growth of the two nematode-trapping fungi (Dactylaria brochopaga and Arthrobotrys conoides) attacking J2 of Meloidogyne incognita were studied in the laboratory. A field experiment was conducted in a tomato field. The mortality percentages were higher in combining EPNs and trapping fungi than either by trapping fungi or EPNs alone. Combining EPNs with A. comcaides fungi caused mortality higher than application by EPNs and trapping fungi D. brochopaga. The highest mortality percentage of combined EPNs and trapping fungi on larvae, root galls and egg-masses of M. incognita in tomato field were in the treatment of combined EPNs and D. brochopaga several times and the treatment of combined EPNs and A. comcaides several times, followed by the treatment of combined EPNs and D. brochopaga one time, and treatment of combined EPNs and A. comcaides one time. In the third stage came the treatment of D. brochopaga alone, and the treatment of A. comcaides alone, finally came effects of the treatment of EPNs alone. The highest tomato yield was recorded in treatments of combined EPNs and D. brochopaga or A. comcaides compared to the separate treatments and control. Thus, we recommend farmers to use combination of EPNs and trapping fungi for increasing the mortality of M. incognita in tomato fields.

Nematophagous Fungi Associated with Root Galls of Rice Caused by Meloidogyne graminicola and its Control by Arthrobotrys dactyloides and Dactylaria brochopaga

AbstractRoot galls of rice caused by Meloidogyne graminicola were examined for natural colonization by nematophagous fungi from four fields with different nematode infestations. Old galls from severely infested fields had a higher frequency of Monacrosporium eudermatum and Stylopaga hadra than young galls. The frequency of Arthrobotrys oligospora, Arthrobotrys dactyloides, Dactylaria brochopaga and Monacrosporium gephyropagum was lower. A greater proportion (%) of root galls were colonized by nematophagous fungi in those fields in which rice roots had a greater root gall index. This indicated that disease severity supported the colonization of galls by nematophagous fungi. In vitro predacity tests of four fungi showed that A. dactyloides was most effective in capturing and killing J2 of Mel. graminicola followed by D. brochopaga and Mon. eudermatum. Application of inocula of A. dactyloides and D. brochopaga in soil infested with Mel. graminicola, respectively, reduced the number of root galls by 86% and of females by 94%, and eggs and juveniles by 94%. The application of these fungi to soil increased plant growth: shoot length by 42.7% and 39.8%, root length by 45.5% and 48.9%, fresh weight of shoot by 59.9% and 56.7% and fresh weight of root by 20.3% and 25.1%, respectively, compared to these parameters for plants grown in nematode‐infested soil.

A New Technique for Single Spore Isolation of Two Predacious Fungi Forming Constricting Ring

A new technique for single spore isolation was developed for predacious fungi forming constricting rings directly on the spores using Dactylaria brochopaga and Arthrobotrys dactyloides. Constricting rings were induced directly on the spores by transferring the spores in 25 ppm solution of DL-Valine in sterile distilled water. Freshly hatched and thoroughly washed second stage juveniles of Meloidogyne incognita were transferred into cavity blocks containing induced rings for trapping and killing of nematodes. The killed nematodes were surface sterilized with streptomycin and inoculated into petri dishes containing maize meal agar media with 100 ppm streptomycin. The petri dishes were incubated at 29±1°C for few days which yielded axenic culture of these fungi.

The influence of bacteria on trap induction in predacious hyphomycetes

The induction of traps by the nematode Panagrellus silusiae in four fungal isolates of Dactylaria brochopaga and Arthro-botrys conoides was strongly influenced by several species of bacteria, which increased the yield mostly in light. In darkness with a stagnant atmosphere and a developing mycelium their effects were drastically altered; some bacteria then promoted the appearance of an abundance of megatraps in Dactylaria brochopaga.

Multilaminate Bodies: Additional Candidates for Membrane Reserve in Trapping Rings ofDactylaria Brochopaga

Heintz and Pramer (1972) studying Arthrobotrys dactyloides Drechs., and Insell and Zachariah (1978) and Dowsett et al. (1977) studying Dactylaria brochopaga Drechs., have all suggested origins for a preformed reserve membrane material, or surface, necessary to accommodate the expansion of the protoplast of ring cells which occurs during the violent closure of the trapping rings produced by these fungi. While material identified by these authors may indeed fulfill the role attributed to them, we have recently identified multilaminate bodies in the cells of trapping rings which may serve as an additional source of membrane reserve material in both normal and giant ring (Tsai et al., 1975) traps of D. brochopaga; it is these we wish to bring to the reader's attention. Cultures of D. brochopaga in which the production of both normal-sized and giant ring traps are phenotypic traits were initiated on half-strength potato-carrot agar (PCA) (Anon., 1968) at 25 C. After 6 da, 7 mm diam agar plugs bearing mycelium were cut from the cultures using a sterile cork borer, and transferred to fresh PC A plates. These plates were taped shut, and incubated in the dark at 25 C for 7 da. At this time the plugs were displaced from their original r sition by rapping the plates sharply either against the palm of the hand or on the laboratory bench. It had been accidently determined that displacement induced formation of relatively large numbers of upright giant rings from that mycelium growing about what had been the circumference of the agar plugs' original position on the agar surface. For transmission electron microscopy, a modification of the procedure used by Dowsett et al. (1977) was employed. Seven-mm agar plugs bearing either normal or giant rings (or both) were cut using a sterile cork borer, trimmed to remove excess agar, and individual plugs were then placed in sterile Parr bottles. Just enough quarter-strength PC medium was added to each bottle to cover the agar plug, and the bottles were incubated at 25 C for up to 72 h. The fluid was then removed from the Parr bottles and the newly developed mycelium and the remains of the agar blocks were fixed following the procedure of Hess (1966), but modified to include Ruthenium Red stain (Luft, 1971). It had earlier been noted that new mycelium developed from plugs derived from the zone of induced giant ring formation described above, also produced giant and normal sized rings. It appears that the ring inducing factor(s) was (were) operative even in the absence of added nematodes, as were employed by Dowsett et al. (1977). The material was then dehydrated in an ethanol series, and embedded in resin (Spurr, 1969). Sections 1094

Multilaminate Bodies: Additional Candidates for Membrane Reserve in Trapping Rings of Dactylaria brochopaga

Multilaminate Bodies: Additional Candidates for Membrane Reserve in Trapping Rings of Dactylaria brochopaga

Observations on predatory fungi

In Arthrobotrys flagrans the chlamydospores are formed, following rupture of the primary hyphal wall, by expansion of the inner wall which then produces warty encrustations over its surface. Evidence is presented to show that in Arthrobotrys anchonia none of the water necessary for expansion of the constricting ring cells comes through the stalk cells. Expansion of constricting rings in Dactylaria brochopaga often appears biphasic with little or no constriction of the host cuticle taking place during the first phase of expansion. Microconidia have been found in three species of predatory fungi with constricting rings. In the presence of nematodes, microconidia germinate directly to produce small, functional, constricting rings.

Transmission and scanning electron microscope observations on the trapping of nematodes by Dactylaria brochopaga

Constricting ring traps of Dactylaria brochopaga Drechs. were found to be effective trapping agents. Nematodes were held by inflation of the ring cells, inflation resulting from changes in the wall of the luminal face of such cells. The wall structure of the ring cells was found to be more complex than has been previously reported for similar fungi. Membrane-bound, osmiophilic, dense-staining, lysosome-like inclusions were found associated with the trapping surface and appear to play a role in both the trapping and the subsequent penetration process. The ultrastructure of (1) the trapping apparatus before and after its inflation and (2) the nematodes and hyphae during the infection process was studied and is reported herein.

The constriction of the trapping rings in Dactylaria brochopaga.

The mechanism of ring constriction of a nematophagous fungus has been studied in vitro. The process of ring constriction in vivo normally requires less than one second. However, precise observations of the mechanism are difficult due to this rapidity, as well as the obstruction of the ring by the nematode. A method of initiating ring constriction without the use of an inert mechanical stimulus is described. With this method it is also possible to retard the constriction of the rings so that accurate observations of the entire process can be made. An explanation of the possible physiological mechanism is also presented.