scholarly journals In Vitro and in Planta Evaluation of Trichoderma asperellum TA as a Biocontrol Agent Against Phellinus noxius, the Cause of Brown Root Rot Disease of Trees

Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2733-2741 ◽  
Author(s):  
Hao Chou ◽  
Yi-Ting Xiao ◽  
Jyh-Nong Tsai ◽  
Ting-Ting Li ◽  
Hung-Yi Wu ◽  
...  

Brown root rot (BRR), caused by the white rot fungus Phellinus noxius, is an epidemic disease of diverse broadleaved and coniferous tree species in many tropical and subtropical regions. Flooding and trenching control measures are difficult to implement, and chemical controls can have an adverse impact on ecosystems. Previous studies have provided in vitro evidence for the potential use of Trichoderma spp. for biocontrol of BRR. Here, we analyzed the in vitro antagonistic and mycoparasitic abilities of four Trichoderma spp. isolates against four P. noxius isolates in dual culture and Ficus microcarpa wood blocks. A convenient inoculation system based on root inoculation of a highly susceptible loquat (Eriobotrya japonica) with P. noxius-colonized wheat-oat grains was developed to examine the effect of Trichoderma treatment in planta. Preventive application of Trichoderma asperellum TA, the isolate showing high antagonistic activity in vitro, was effective in preventing and delaying the wilting of P. noxius-inoculated loquat cuttings in greenhouse trials. To understand the specific niche in which T. asperellum TA interacts with P. noxius, KOH-aniline blue fluorescence microscopy was used to investigate the colonization of loquat roots by P. noxius and/or T. asperellum TA. Dilution plating assays were also conducted to quantify Trichoderma populations in the rhizosphere and potting mix. T. asperellum TA was able to robustly establish in the rhizosphere and potting mix but with scarce root penetration limited to the superficial layer. We discuss the timing and strategy for applying antagonistic Trichodema sp. on living trees or in BRR-infested areas for BRR management.

2021 ◽  
Vol 24 (2) ◽  
pp. 107-120
Author(s):  
SMN Islam ◽  
SS Siddique ◽  
MZH Chowdhury ◽  
NJ Mishu

A native Trichoderma isolate was collected from the agricultural soil of Gazipur. This isolate was identified as a Trichoderma asperellum through morphology and analysis of internal transcribed spacer (ITS) region of ribosomal RNA gene sequence and reconstruction of the phylogenetic tree. The antagonistic effects of the newly identified T. asperellum isolate were assessed against brinjal bacterial wilt caused by Ralstonia solanacearum both in vitro and in planta. Both qualitative and quantitative bioassays were conducted in vitro. For qualitative tests, dual culture and antibacterial activity were carried out, and pathogen growth was observed visually. The antagonism of T. asperellum cell free culture filtrate on the growth of R. solanacearum was conducted in a quantitative test. Successful antagonism was recorded after both in vitro qualitative tests. In addition, the lowest colony forming unit was recorded in 100% of CFC (2.4±0.51 ×103 cfu/ml) in quantitative test. The T. asperellum inoculated plant showed low disease incidence (13.33%) when seedlings were challenged with R. solanacearum in planta experiment. Disease incidence was 100% for seedlings when treated with only R. solanacearum. The results showed that the isolated and identified T. asperellum isolate suppressed R. solanacearum growth in vitro and protected the seedling from wilting in planta. Therefore, this isolate could be considered as a potential isolate. Ann. Bangladesh Agric. (2020) 24(2) : 107-120


Author(s):  
Anam Choudhary ◽  
Shabbir Ashraf

AbstractThe present study was carried out to evaluate the effect of bioagents and organic amendments in suppressing the dry root rot of mungbean incited by Rhizoctonia bataticola. The locally isolated pathogen and fungal biocontrol agents were identified based on morphological and molecular characterization. These identified bioagents were tested in vitro, and the highest mycelial inhibition was recorded in dual culture assay by Trichoderma harzianum (74.44%), and among organic amendments, maximum mycelial inhibition was found in neem cake (61.11%). In a greenhouse study, T. harzianum + neem cake effectively enhanced the percent germination (93.33%) and decreased the percent disease mortality (11.67%) than the other treatments. The morphological parameter like plant height (57.50 cm), dry weight (22.83 g) root nodules (51), pods/plant (58), and 100-seed weight (5.78 g) were found to be at the maximum in this combined application. Physiological pigments viz. chlorophyll (2.41 mg/g) and carotenoids (0.19 mg/g), protein content (5.85 mg/g), and leghemoglobin (11.75 mg/g) were also found to be maximum in T. harzianum + neem cake and minimum phenol content (1.41 mg/g). The study concludes that T. harzianum + neem cake can be recommended as an effective approach for the management of dry root rot of mungbean.


Author(s):  
Ma. Ángeles Valencia de Ita ◽  
Jiménez Huerta Fátima ◽  
Conrado Parraguirre Lezama ◽  
Alfredo Báez Simón ◽  
Gerardo Landeta Cortés ◽  
...  

Diversity of the different types of chilies in Mexico has been scarcely studied, and a large variety have been found to be, such as Manzano chili. Root rot caused by oomycete Phytophthora capsici is a severe disease that affects Manzano chili production in Mexico, detracted from its production and quality. The use of biological control agents such as Trichodermanative’s species, represents an efficient alternative to reduce losses and control the disease. For this reason, the objective of the present investigation was to evaluate the antagonistic effect in vitro and in vivo of four native strains of Trichoderma spp., on Phytophthora capsici in seedlings of Manzano chili from Puebla-Mexico was evaluated. Dual culture technique was used to determine the percentage of inhibition of radial growth (PICR) of the PC-A strain of P. capsici. Analysis of the percentage of germination was also carried out, as well as the incidence of root rot at 20 days after inoculation with the pathogen (dai) in the nursery. T. harzianum strain presented the highest PICR (42.86%) of antagonistic level in vitro and class I in the Bell scale, in addition, it obtained 88% germination in the nursery and 10% mortality at 20 dai, higher than the other native strains of Trichoderma. The bio-controlling effect of strains of Trichoderma spp., offers an effective alternative for root necrosis caused by P. capsici in the cultivation of Manzano chili in Puebla-Mexico.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1220
Author(s):  
Petra Andrade-Hoyos ◽  
Hilda Victoria Silva-Rojas ◽  
Omar Romero-Arenas

Avocado root rot caused by the oomycete Phytophthora cinnamomi is a severe disease that affects avocado production in Mexico and worldwide. The use of biological control agents such as Trichoderma species isolated from places where the disease is always present, represents an efficient alternative to reduce losses. Thus, the objective of this research was to evaluate the biocontrol ability of 10 endophytic Trichoderma spp. strains against P. cinnamomi tested both in vitro and in the greenhouse. The endophytic Trichoderma spp. were recovered from Persea americana and Cinnamomum verum roots, isolated and purified on potato–dextrose–agar medium. Ten strains were identified by phylogenetic reconstruction of the internal transcribed spacer region of rDNA sequences as T. asperellum (T-AS1, T-AS2, T-AS6, and T-AS7), T. harzianum (T-H3, T-H4, and T-H5), T. hamatum (T-A12), T. koningiopsis (T-K8 and T-K11), and P. cinnamomi (CPO-PCU). In vitro dual-culture assay, the percentage of inhibition of radial growth (PIRG) between Trichoderma spp. and P. cinnamomi strains was measured according to the Bell’s scale. PIRG results indicated that T-AS2 reached the highest value of 78.32%, and T-H5 reached the lowest value of 38.66%. In the greenhouse, the infection was evaluated according to the percentage of disease incidence. Plants with the lowest incidence of dead by avocado root rot were those whose seedlings were inoculated with T-AS2 and T-AS7, resulting in only 5% death by root rot caused by P. cinnamomi. The disease incidence of seedlings with wilt symptoms and death decreased more than 50% in the presence of Trichoderma spp. Relying on the results, we conclude that T. asperellum and T. harzianum contribute to the biocontrol of soil-borne pathogenic oomycete P. cinnamomi.


2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.


2021 ◽  
Vol 7 (1) ◽  
pp. 46
Author(s):  
Warin Intana ◽  
Suchawadee Kheawleng ◽  
Anurag Sunpapao

Postharvest fruit rot caused by Fusarium incarnatum is a destructive postharvest disease of muskmelon (Cucumis melo). Biocontrol by antagonistic microorganisms is considered an alternative to synthetic fungicide application. The aim of this study was to investigate the mechanisms of action involved in the biocontrol of postharvest fruit rot in muskmelons by Trichoderma species. Seven Trichoderma spp. isolates were selected for in vitro testing against F. incarnatum in potato dextrose agar (PDA) by dual culture assay. In other relevant works, Trichoderma asperellum T76-14 showed a significantly higher percentage of inhibition (81%) than other isolates. Through the sealed plate method, volatile organic compounds (VOCs) emitted from T. asperellum T76-14 proved effective at inhibiting the fungal growth of F. incarnatum by 62.5%. Solid-phase microextraction GC/MS analysis revealed several VOCs emitted from T. asperellum T76-14, whereas the dominant compound was tentatively identified as phenylethyl alcohol (PEA). We have tested commercial volatile (PEA) against in vitro growth of F. incarnatum; the result showed PEA at a concentration of 1.5 mg mL−1 suppressed fungal growth with 56% inhibition. Both VOCs and PEA caused abnormal changes in the fungal mycelia. In vivo testing showed that the lesion size of muskmelons exposed to VOCs from T. asperellum T76-14 was significantly smaller than that of the control. Muskmelons exposed to VOCs from T. asperellum T76-14 showed no fruit rot after incubation at seven days compared to fruit rot in the control. This study demonstrated the ability of T. asperellum T76-14 to produce volatile antifungal compounds, showing that it can be a major mechanism involved in and responsible for the successful inhibition of F. incarnatum and control of postharvest fruit rot in muskmelons.


Author(s):  
Tse‐Yen Liu ◽  
Chao‐Han Chen ◽  
Yu‐Liang Yang ◽  
Isheng J. Tsai ◽  
Ying‐Ning Ho ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
E. K. Wanjiku ◽  
J. W. Waceke ◽  
J. N. Mbaka

Demand for organic avocado fruits, together with stringent food safety standards in the global market, has made producers to use alternative, safe, and consumer-friendly strategies of controlling the postharvest fungal disease of avocado fruits. This study assessed the in vitro efficacy of Trichoderma spp. (T. atroviride, T. virens, T. asperellum, and T. harzianum) against isolated avocado stem-end rot (SER) fungal pathogens (Lasiodiplodia theobromae, Neofusicoccum parvum, Nectria pseudotrichia, and Fusarium solani) using a dual culture technique. The Trichoderma spp. were also evaluated singly on postharvest “Hass” avocado fruits. Spore suspension at 5 × 104 conidial/ml of the Trichoderma spp. was applied on the avocado fruits at three time points, twenty-four hours before the fungal pathogen (preinoculation), at the same time as the fungal pathogen (concurrent inoculation), and 24 hours after the fungal pathogen (postinoculation). In the in vitro study, T. atroviride showed the highest mycelial growth inhibition against N. parvum (48%), N. pseudotrichia (55%), and F. solani (32.95%), while T. harzianum had the highest mycelial growth inhibition against L. theobromae. Trichoderma asperellum was the least effective in inhibiting the mycelial growth of all the pathogens. Similarly, T. virens showed the highest mycelial growth inhibition against N. pseudotrichia at 45% inhibition. On postharvest “Hass” fruits, T. atroviride showed the highest efficacy against N. parvum, N. pseudotrichia, and F. solani in all the applications. Trichoderma virens and T. harzianum were most effective against all the pathogens during postinoculation, while Lasiodiplodia theobromae was best controlled by T. virens, T. harzianum, and T. asperellum during postinoculation. Both T. atroviride and T. harzianum present a potential alternative to synthetic fungicides against postharvest diseases of avocado fruits, and further tests under field conditions to be done to validate their efficacy. The possibility of using Trichoderma spp. in the management of SER on avocado fruits at a commercial level should also be explored.


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