scholarly journals In vitro investigations on the biological control of Xiphinema index with Trichoderma species

2013 ◽  
Vol 50 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Á. Daragó ◽  
M. Szabó ◽  
K. Hrács ◽  
A. Takács ◽  
P. Nagy
Keyword(s):  
Biological Control ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Xiphinema Index ◽  
Promising Tool ◽  
Innate Ability ◽  
Plant Parasitic

AbstractThe application of Trichoderma spp. for the suppression of plant-parasitic nematode populations is a promising tool in biological control. Sixteen strains of six Trichoderma species (T. atroviride, T. harzianum, T. rossicum, T. tomentosum, T. virens and T. asperellum) were tested in vitro in order to identify the most appropriate strains to control the dagger nematode Xiphinema index. Mortality assays revealed that the strains of the widely investigated T. harzianum species have caused significant reduction of X. index populations, although T. harzianum strains were not the most efficient among all the tested fungi. Certain T. virens and T. atroviride strains and T. rossicum have triggered faster and higher mortality. Generally, our data indicate that Trichoderma species have innate ability to decrease X. index population. Furthermore, as we had difficulties with maintaining X. index in vitro, we successfully used a newly developed method to keep X. index specimens viable during the experiments.

scholarly journals Trichoderma Biological Control to Protect Sensitive Maize Hybrids Against Late Wilt Disease in the Field

2021 ◽  
Vol 7 (4) ◽  
pp. 315
Author(s):  
Ofir Degani ◽  
Shlomit Dor
Keyword(s):  
Biological Control ◽  
Growth Parameters ◽  
Crop Protection ◽  
Antagonistic Activity ◽  
Trichoderma Spp ◽  
Maize Crop ◽  
Trichoderma Species ◽  
Maize Cultivars ◽  
Pathogen Dna

Late wilt, a disease severely affecting maize fields throughout Israel, is characterized by the relatively rapid wilting of maize plants from the tasseling stage to maturity. The disease is caused by the fungus Magnaporthiopsis maydis, a soil and seed-borne pathogen. The pathogen is controlled traditionally through the use of maize cultivars having reduced sensitivity to the disease. Nevertheless, such cultivars may lose their immunity after several years of intensive growth due to the presence of high virulent isolates of M. maydis. Alternative effective and economical chemical treatment to the disease was recently established but is dependent on the use of a dripline assigned for two adjacent rows and exposes the risk of fungicide resistance. In the current work, eight marine and soil isolates of Trichoderma spp., known for high mycoparasitic potential, were tested as biocontrol agents against M. maydis. An in vitro confront plate assay revealed strong antagonistic activity against the pathogen of two T. longibrachiatum isolates and of T. asperelloides. These species produce soluble metabolites that can inhibit or kill the maize pathogen in submerged and solid media culture growth assays. In greenhouse experiments accompanied by real-time PCR tracking of the pathogen, the Trichoderma species or their metabolites managed to improve the seedlings’ wet biomass and reduced the pathogen DNA in the maize roots. A follow-up experiment carried out through a whole growth session, under field conditions, provided important support to the Trichoderma species’ beneficial impact. The direct addition of T. longibrachiatum and even more T. asperelloides to the seeds, with the sowing, resulted in a yield improvement, a significant increase in the growth parameters and crops, to the degree of noninfected plants. These bioprotective treatments also restricted the pathogen DNA in the host tissues (up to 98%) and prevented the disease symptoms. The results encourage more in-depth research to uncover such biological agents’ potential and the methods to implement them in commercial fields. If adequately developed into final products and combined with other control methods, the biological control could play an important role in maize crop protection against Late wilt.

scholarly journals In Vitro Acquisition of Specific Small Interfering RNAs Inhibits the Expression of Some Target Genes in the Plant Ectoparasite Xiphinema index

2019 ◽  
Vol 20 (13) ◽  
pp. 3266 ◽  
Author(s):  
Aurélie Marmonier ◽  
Laetitia Perfus-Barbeoch ◽  
Corinne Rancurel ◽  
Sylvaine Boissinot ◽  
Bruno Favery ◽  
...  
Keyword(s):  
Rna Interference ◽  
Target Genes ◽  
Parasitic Nematode ◽  
Nematode Species ◽  
Small Interfering Rnas ◽  
Grapevine Fanleaf Virus ◽  
Transcriptomic Data ◽  
Xiphinema Index ◽  
Plant Parasitic

Xiphinema index is an important plant parasitic nematode that induces direct damages and specifically transmits the Grapevine fanleaf virus, which is particularly harmful for grapevines. Genomic resources of this nematode species are still limited and no functional gene validation technology is available. RNA interference (RNAi) is a powerful technology to study gene function and here we describe the application of RNAi on several genes in X. index. Soaking the nematodes for 48 h in a suspension containing specific small interfering RNAs resulted in a partial inhibition of the accumulation of some targeted mRNA. However, low reproducible silencing efficiency was observed which could arise from X. index silencing pathway deficiencies. Indeed, essential accustomed proteins for these pathways were not found in the X. index proteome predicted from transcriptomic data. The most reproducible silencing effect was obtained when targeting the piccolo gene potentially involved in endo-exocytosis of synaptic molecules. This represents the first report of gene silencing in a nematode belonging to the Longidoridae family.

Effects of exogenous amino acid applications on the plant-parasitic nematode Heterodera schachtii

Nematology ◽  
2018 ◽  
Vol 20 (8) ◽  
pp. 713-727 ◽  
Author(s):  
Roman Christopher Blümel ◽  
Daniel F. Fischer ◽  
Florian M.W. Grundler
Keyword(s):  
Amino Acid ◽  
Host Plant ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Direct Effects ◽  
Derivatives Of ◽  
Plant Parasitic

Summary Amino acid (AA) applications have been reported to affect plant-parasitic nematodes. Here, we analysed the effects of methionine (Met), lysine (Lys), threonine (Thr), isoleucine (Ile), homoserine (Hom) and tryptophan (Trp) on the sedentary plant-parasitic nematode, Heterodera schachtii, under in vitro conditions. No AA showed direct effects on the activity of infective second-stage juveniles (J2) of H. schachtii. Soaking J2 in Lys for 24 h increased the number of developing females and reduced the number of males. Thr treatments reduced the total number of nematodes developing in the host plant. The strongest effects were observed when AA were added to the nutrient medium in a monoxenic Arabidopsis thaliana culture. Ile, Met or Thr clearly reduced the number of female nematodes developing in the host plant. These AA are direct metabolic derivatives of Hom. Direct effects on pre-infective J2 can be differentiated from effects that may involve the host plant.

Management of collar rot disease in chickpea by Trichoderma species

2020 ◽  
Vol 7 (03) ◽  
Author(s):  
PREM PANDEY ◽  
G. C. SAGAR ◽  
SUNDARMAN SHRESTHA2 ◽  
HIRAKAJI MANANDHAR ◽  
RITESH K. YADAV ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Maximum Growth ◽  
Pot Experiment ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Collar Rot ◽  
Rot Disease

Nine isolates of Trichoderma spp. were isolated from different agro- ecological regions of Nepal viz; Jumla, Palpa, Chitwan, Tarahara, Banke, Illam and Salyan and screened against Sclerotium rolfsii Sacc. Adreded soil borne phytopathogen causing collar rot of chickpea in chickpea; In-vitro efficacy of nine fungal antagonist (Trichoderma spp.) against Sclerotium rolfsii were screened. Pot experiment was done to find out the effective management of S. rolfsi through Tricoderma using different methods i.e. Seed treatment, soil drenching and soil application. All the tested isolates of Trichoderma spp. were found effective on mycelial growth inhibition and sclerotial parasitization of S. rolfsii. Trichoderma isolated from Palpa district showed maximum growth inhibition (%) of pathogen periodically after 48(93.78%), 72(96.00%), 96(97.96%) and 120(100.00%) hours of inoculation. Parasitized sclerotium showed minimum sclerotial germination on agar plates. Moreover, Trichoderma species isolated from Palpa districts showed second best percent mycelial growth inhibition periodically at 72(25.00%), 120(29.16%), 168(29.16%) and 216(29.16%).In pot experiment at 40 days after sowing, Seedling height was maximum in soil drenching with 30g per 100ml of water (22.27cm) and Mortality percentage of seedlings was least or highest disease control was observed in seed treated with 109cfu/ml (0.000%).

scholarly journals The role of Caenorhabditis elegans sex-determination homologs, Mi-sdc-1 and Mi-tra-1 in Meloidogyne incognita

2021 ◽  
Author(s):  
Anil Baniya ◽  
Soumi Joseph ◽  
Larry Duncan ◽  
William Crow ◽  
Tesfamariam Mengistu
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
Meloidogyne Incognita ◽  
Egg Production ◽  
Target Genes ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Root Knot Nematode ◽  
Model Free ◽  
Plant Parasitic

AbstractSex determination is a key developmental event in all organisms. The pathway that regulates sexual fate has been well characterized at the molecular level in the model free-living nematode Caenorhabditis elegans. This study aims to gain a preliminary understanding of sex-determining pathways in a plant-parasitic nematode Meloidogyne incognita, and the extent to which the roles of the sex determination genes are conserved in a hermaphrodite species, C. elegans, and plant-parasitic nematode species, M. incognita. In this study, we targeted two sex-determining orthologues, sdc-1 and tra-1 from M. incognita using RNA interference (RNAi). RNAi was performed by soaking second-stage juveniles of M. incognita in a solution containing dsRNA of either Mi-tra-1or Mi-sdc-1 or both. To determine the effect of RNAi of the target genes, the juveniles treated with the dsRNA were inoculated onto a susceptible cultivar of cowpea grown in a nutrient pouch at 28 °C for 5 weeks. The development of the nematodes was analyzed at different time points during the growth period and compared to untreated controls. Our results showed that neither Mi-sdc-1 nor Mi-tra-1 have a significant role in regulating sexual fate in M. incognita. However, the silencing of Mi-sdc-1 significantly delayed maturity to adult females but did not affect egg production in mature females. In contrast, the downregulation of Mi-tra-1 transcript resulted in a significant reduction in egg production in both single and combinatorial RNAi-treated nematodes. Our results indicate that M. incognita may have adopted a divergent function for Mi-sdc-1 and Mi-tra-1distinct from Caenorhabditis spp. However, Mi-tra-1 might have an essential role in female fecundity in M. incognita and is a promising dsRNA target for root-knot nematode (RKN) management using host-delivered RNAi.

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