Abstract
Background
Trichoderma asperellum (Ascomycota: Hypocreaceae) is a globally recognized soil fungus due to its broad-spectrum antimicrobial and plant growth-promoting properties. To increase the availability of local strains, soil samples from a dragon fruit farm in Villanueva (Misamis Oriental, Philippines) were collected and baited using the insect-baiting technique.
Results
Using the baiting technique, T. asperellum strain, RMCK01, was isolated. The strain was characterized using morphological and molecular data and its biological control potential was tested using different conidial concentrations on the last larval instar of the super worm, Zophobas morio (Fabricius, 1776) (Coleoptera: Tenebrionidae). The ITS1 sequences of T. asperellum RMCK01 were 100% identical to the sequences of other T. asperellum isolates reported from Vietnam, India, Thailand, and China. In addition, T. asperellum RMCK01 was particularly efficient against Z. morio larvae. On day 21, 88.87%, 88.07%, and 86.73% of insects died when treated with a suspension containing 6 × 108, 3 × 109, and 2.68 × 107 conidia/ml, respectively.
Conclusion
The study highlights the potential of this fungal isolate as a biocontrol agent against insect pests.
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Background
A major current environmental problem is caused by the indiscriminate use of pesticides under certain agricultural systems (Ortiz-Hernández et al. 2014). Pesticidal spraying can reduce or even eliminate the economic costs caused by plant diseases, insect pests, and weeds. However, there are increasing concerns regarding the overuse of pesticides in agriculture as they cause health problems for humans and animals and cause irreversible damage to the ecosystems. Moreover, their use is not always efficient as many pests have developed resistance against pesticides, for instance (Alvarez et al. 2017). Under these circumstances, biological control agents (BCAs) have recovered major importance. The use of beneficial microbes can, for instance, help meet the growing global demand for plant products sustainably, without relying entirely on synthetic pesticides.
Members of the fungal genus Trichoderma (Ascomycota: Hypocreaceae) are primarily recognized as BCAs with antagonistic effects against a wide array of fungal phytopathogens, pathogenic bacteria like Ralstonia solanacearum, and lepidopteran insect pests (Mohamed et al. 2020). Trichoderma asperellum (Samuels et al. 1999), although less studied, is also a successful BCA against many plant pathogens (Wu et al. 2017), and its larvicidal potential has been recently recognized (Podder and Ghosh 2019). Some Trichoderma-based products are often commercialized as BCAs against phytopathogens and as biofertilizers or growth promoters (Woo et al. 2014). The biocontrol mechanisms mainly include competition and mycoparasitism, followed by the stimulation of plant resistance and immunity (Sood et al. 2020). Amid their commercial success, a major drawback of these microbial-based fungicides is that not all strains perform the same under different environmental conditions. The collection and characterization of locally adapted strains may increase the availability of highly efficient Trichoderma strains (El Komy et al. 2015).
In this study, a T. asperellum isolate, RMCK01, was isolated, in the southern Philippines (Villaneuva, Misamis Oriental), characterized at the morphological and molecular levels. Its biological control potential was evaluated against the super worm, Zophobas morio (Fabricius, 1776) (Coleoptera: Tenebrionidae) larvae. To our knowledge, this is the first study to assess the biocontrol potential of T. asperellum against a coleopteran insect. The findings of this study pave the way and open the door to the potential application of a new bioinsecticide based on a naturally occurring entomopathogenic fungus.
Methods
Fungal isolation
The fungus was isolated from soil samples collected from a dragon fruit (Hylocereus cactus) farm in Villanueva, Misamis Oriental, Philippines (8.59654° N, 124.79971° E), in November 2019. To this end, the insect-baiting technique was used according to the procedure developed by Bedding and Akhurst (1975). Briefly, moistened soil samples were placed in plastic containers. Then, 5 last instar larvae, Z. morio, were added into each container (Navarez et al. 2021). Containers were sealed and stored in the dark at 25 ± 2 °C. Containers were inspected every other day, for 15 days, until visible symptoms of fungal infection were observed. Insect cadavers showing fungal infection were transferred to Sabouraud dextrose agar (SDA-Scharlau) media for purification (Herlinda et al. 2020). To inhibit the growth of bacteria, the media was supplemented with streptomycin, a broad-spectrum antibiotic, at a concentration of 20 µg/l (Goettel and Inglis 1997).
Morphological identification
Isolated fungi were identified based on phenotypic characteristics in SDA and PDA (Potato dextrose agar) media. Characteristics such as surface texture, surface margin, surface topography, surface pigmentation, reverse pigmentation, and growth rate were taken into account. In addition, microscopic characteristics such as the length and shape of conidia were taken into account for initial identification using the key described by Humber (1997).
Molecular identification
Genomic DNA (gDNA) of the fungal isolate was extracted using PureLink® Genomic Plant DNA Purification Kit (Thermo Fisher Scientific). Gene amplification by PCR was carried out with the following components: 3 µl of gDNA, 1 µl of ITS1 (5′tccgtaggtgaacctgcgg-3′) and 1 µl of ITS4 (5′-tcctccgcttattgatatgc-3′) primers, 2.5 µl of Taq buffer, 0.5 µl of DNA polymerase, 1 µl of dNTP mix, and 1 µl nuclease-free dH2O. Cycling parameters on the thermal cycler were set at 95 °C for 5 min, followed by 30 cycles at 95 °C for 60 s, 58 °C for 45 s, 70 °C for 60 s, and a final extension at 72 °C for 10 min. Amplicons generated had sizes ranging from 400 to 600 bp, which was expected for ITS1 and ITS4 primers (Additional file 1: Fig. S1). Capillary sequencing was performed in a bidirectional manner at the Philippine Genome Center-Core Sequencing Facility (Manila, Philippines). Fluorescent-labeled chain terminator dNTPs with the reaction components, viz. amplicons, primers, and ABI BigDye® Terminator v3.1 Cycle Sequencing Kit (Thermo Fisher Scientific), were used. Cycling parameters on Bio-Rad T100 Thermal Cycler include: pre-hold at 4 °C; 96 °C for 60 s; 25 cycles of 96 °C for 10 s, 50 °C for 5 s, 62 °C for 4 min and hold at 4 °C. Ethanol precipitation was carried out to remove unincorporated dNTPs, excess primers, and primer dimers. Capillary electrophoresis was carried out on the ABI 3730×l DNA Analyzer using a 50 cm 96-capillary array, POP7TM Polymer, and 3730×l Data Collection Software v3.1. Base-calling was carried out on the Sequencing Analysis Software v5.4.
Sequences alignment and phylogenetic analysis
The generated sequences were manually curated and trimmed in BioEdit (Hall, 1999). The obtained sequences were searched in the National Centre for Biotechnology (NCBI) data bank using the nucleotide basic local alignment search tool (BLASTn) (Altschul et al. 1990). Sequences of Trichoderma asperellum RMCK01 were aligned with sequences of other related fungi species using default ClustalW parameters in MEGA 7.0 (Kumar et al. 2016) and optimized manually in BioEdit (Hall 1999), and sequences were only trimmed at both extremes after alignment to maintain fragments with similar length. Pairwise distances were computed using MEGA 7.0 (Kumar et al. 2016). Codon positions included were 1st + 2nd + 3rd + Non-coding. The base substitution model was evaluated using jModelTest 0.1.1 (Posada 2008).
The phylogenetic tree was inferred from the datasets using the Bayesian inference method (BI). All characters were treated as equally weighted and gaps as missing data. Trichoderma longibrachiatum (EU401556.1) and T. brunneoviride (EU518659.1) were used as out-groups. Bayesian phylogenetic reconstructions were performed using MrBayes 3.2.7 (Ronquist et al. 2012). The best fit model was identified as the GTR + G model test using the MrModeltest 2.0 program (Nylander 2004). Metropolis-coupled Markov chains Monte Carlo (MCMCMC) generations were run for 1 × 106 cycles, and one tree was retained every 2000 generations. The Bayesian tree was visualized using the FigTree program 1.4.4 (Rambaut 2018). In addition, genetic pairwise distances were estimated using MEGA-7 software (Kumar et al. 2016).
Mass production of spores
Mass production of spores was carried out following the method of Podder and Gosh (2019). For this, 50 g of rice was washed thoroughly under running tap water and soaked in water for 3 h. The soaked rice was transferred to a 15 × 30 cm polypropylene plastic bags and then autoclaved, maintaining a temperature of 121 °C for 15 min under 15 psi. The sterilized rice was allowed to cool down at room temperature. Then, the rice was inoculated by T. asperellum spores under a biological safety cabinet. Trichoderma asperellum spores were produced by growing the fungus on the rice. The inoculated rice was incubated at 28 ± 1 °C for 15 days (Fig. 1A).
Preparation of inoculum and quantification
Conidial concentrations were estimated based on the protocol of Goettel and Inglis (1997), with slight modifications. Briefly, mycelium was harvested, washed with distilled water, and filtered through a cheesecloth. Then, Tween 80 (0.05%) was added and 100 µl of conidial suspension was pipetted and mixed with 100 µl of sterile lactophenol blue stain solution (Barta 2010). This suspension was vortexed for 30 s and serially diluted with sterile deionized water. The number of conidia in each sample was determined using a hemocytometer (Neubauer, Marienfeld, Germany). Then, 3 conidial suspensions were prepared. Spores were counted under microscopic power of 40× and calculated using the formula (Kamaruzzaman et al. 2016):
Finally, the suspension was standardized to 3 final concentrations using C1V1 = C2V2 formula.
Pathogenicity tests
To test the pathogenicity of T. asperellum isolate RMCK01, the last instar Z. morio larvae were treated with 3 conidial suspensions: 2.68 × 107, 6 × 108, or 3 × 109 conidia/ml. These 3 concentrations were selected based on previous studies (Mohamed 2019). Zophobas morio larvae were immersed into one conidial suspension for 60 s and then let to air dry. All insects were then transferred to 9 cm diameter clean glass Petri dishes. A piece of filter paper (9 cm in diameter) was placed at the bottom of the dish with a few drops of water. Controls were dipped into a 0.02% solution of Tween-80 prepared with distilled water. Experiments were repeated 4 times with a new batch of insects and new conidial suspensions, and for each repetition, there were 5 Z. morio larvae. Bioassays were incubated at 26 °C and > 95% relative humidity (RH). Insect mortality and fungal infection symptoms were recorded at 12 h intervals for 21 days (Fig. 1B).
Statistical analysis
Results of statistical analysis are expressed as mean ± standard deviation (n = 3) with 5 replications. To determine whether there were significant differences (p < 0.05), one-way ANOVA was used, followed by Tukey’s HSD test (XLSTAT version 2020.1.3) for post hoc analysis.
Results
Morphological characterization
Trichoderma asperellum RMCK01 mycelia were white and dark green, and arranged in 5 concentric rings, each of either white or dark green color when grown for 3 days in PDA media (Fig. 2A). When grown for 3 days in SDA media, mycelium was white with a hint of green, had a cottony texture, and forms a few concentric rings (Fig. 2B). Conidia were subglobose to globose or ovoidal (Fig. 2C, D) (Table 1).
Molecular characterization and phylogenetic relationships
Trichoderma asperellum RMCK01 had a G + C content of 56.41% and an A + T content of 43.59% in the sequences of ITS rDNA (507 bp) flanked by primers ITS1 and ITS4. These sequences were identical to other ITS rDNA sequences, available from the GenBank, of other T. asperellum strains isolated in Vietnam, India, Thailand, and China, suggesting that they are conspecific. The phylogenetic tree reconstructed using a Bayesian inference model supports this notion (Fig. 3). Trichoderma asperellum RMCK01 formed a well-supported clade with other T. asperellum isolates from Vietnam, India, Thailand, and China. Furthermore, the phylogenetic analyses showed that T. asperellum was a sister group to the clade formed by Trichoderma koningiopsis, T. asperelloides, T. viride, T. yunnanense, and T. hamatum.
Pathogenicity of T. asperellum on super worm larvae
The first dead insects were observed as early as 24 h post-infection. Three days after insect death, T. asperellum RMCK01 sporulated, and white mycelia were observed on Z. morio larvae (Fig. 3). On day 7 after inoculation, significant mortality, compared to controls, was observed independently of the conidial concentration used (Fig. 4). Average mortality of larvae after 7 days ranged from 49.52 to 62.26% (Fig. 4A). On day 14 after inoculation, insect mortalities ranged between 79 and 88.07% (Fig. 4B). On day 21 post-inoculation, insect mortalities reached more than 86% (Fig. 4C). Hence, the highest mortality rate of Z. morio larvae by T. asperellum was recorded on day 21 with a suspension of 6 × 108 (88.87%), followed by 3 × 109 (88.07%) and the least infection was from 2.68 × 107 conidia/ml (86.73%).
Discussion
Use of Trichoderma, as a biocontrol agent against insect pests, has been studied in recent years, uncovering this group of fungi as a promising alternative to be used in sustainable agriculture not only because of its efficiency against plant pathogens but also insect pests (Poveda 2021). The reports of its economic importance in the agricultural industry and the characteristics of Trichoderma that produces large amounts of fungal spores make it ideal for inoculum production under laboratory conditions (Herrera-Téllez et al. 2019). In this study, evidence that T. asperellum naturally occurs in agricultural soils in the Philippines was presented and it can be grown under laboratory conditions and is highly pathogenic against Z. morio larvae.
Several studies show the biological control potential of T. asperellum against plant diseases (Vilcacundo et al. 2020); at the same time, it improves plant growth and development (Moreira et al. 2021) in several plant species and also bioremediation qualities are shown (Li et al. 2021). Furthermore, a more recent study reports that this fungal species can have larvicidal effects against Anopheles spp., the vector of malaria and Aedes aegypti (da Silveira et al. 2021). The potential of T. asperellum to control other insect pests has not been shown yet. Hence, to determine the potential of T. asperellum and to control other insect pests, its pathogenicity against Z. morio was evaluated under laboratory conditions. The present experimental results showed that T. asperellum strain RMKC had also a great potential to control Z. morio larvae as the insect mortality was observed a few days after fungal applications, which reached about 86–88% within 21 days after treatments. The presented results indicate a considerable potential for use of T. asperellum as an entomopathogenic fungus to control insect pests with the suspension even as low as 2.7 × 107 conidia/ml. Notwithstanding the present results, additional experiments to focus on long shelf life, ease of application, pathogen and pest virulence, and a wider spectrum of action and yield assessments must be conducted before ultimate conclusions are presented. Furthermore, a technology for co-cultivation of 2 microbes, in particular, T. asperellum GDFS1009 and B. amyloliquefaciens 1841 (Karuppiah et al. 2019), and T. asperellum and Bacillus subtilis (Senkovs et al. 2021) has been recently reported to significantly enhance the plant growth and protection against plant pathogens. Thus, to utilize its various benefits, co-cultivation with other microbes is also recommended for further study of T. asperellum.
Conclusions
Trichoderma asperellum RMKC01, isolated from an agricultural soil, was highly pathogenic against the larvae of the super worm, Z. morio. Further studies to evaluate its pathogenicity against other insect pests and non-targeted organisms are required to assess its real potential to be used as a biocontrol agent in organic and eco-friendly agricultural settings.
Availability of data and materials
All available data are included in this manuscript. The DNA sequence data have been submitted to the NCBI GenBank data repository.
Abbreviations
- BCA:
-
Biological control agent
- gDNA:
-
Genomic DNA
- PDA:
-
Potato dextrose agar
- SDA:
-
Sabouraud dextrose agar
- T. asperellum :
-
Trichoderma asperellum
- Z. morio :
-
Zophobas morio
References
Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ (1990) Basic local alignment search tool. J Mol Biol 215(3):403–410. https://doi.org/10.1016/s0022-2836(05)80360-2
Alvarez A, Saez JM, Davila Costa JS, Colin VL, Fuentes MS, Cuozzo SA, Amoroso MJ (2017) Actinobacteria: current research and perspectives for bioremediation of pesticides and heavy metals. Chemosphere 166:41–62. https://doi.org/10.1016/j.chemosphere.2016.09.070
Barta MA (2010) Pathogenicity assessment of entomopathogenic fungi infecting Leptoglossus occidentalis (Heteroptera: Coreidae). Czech Mycol 62(1):67–78
Bedding RA, Akhurst RJ (1975) A simple technique for the detection of insect parasitic rhabditid nematodes in soil. Nematologica 21(1):109–110. https://doi.org/10.1163/187529275x00419
da Silveira AA, Andrade JSP, Guissoni ACP, Costa AC, Carvalho e Silva A, Silva HG, Fernandes KF (2021) Larvicidal potential of cell wall degrading enzymes from Trichoderma asperellum against Aedes aegypti (Diptera: Culicidae). Biotechnol Prog 37(5):e3182. https://doi.org/10.1002/btpr.3182
El Komy MH, Saleh AA, Eranthodi A, Molan YY (2015) Characterization of novel Trichoderma asperellum isolates to select effective biocontrol agents against tomato Fusarium Wilt. Plant Pathol J 31(1):50–60. https://doi.org/10.5423/ppj.oa.09.2014.0087
Goettel MS, Inglis GD (1997) Fungi: hyphomycetes. In: Lacey LA (ed) Manual of techniques in insect pathology (Chap. 5–3). Academic Press, San Diego, pp 213–250. https://doi.org/10.1016/b978-012432555-5/50013-0
Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for windows 95/98/NT. Nucleic Acids Symp Ser 41:95–98
Herlinda S, Octariati N, Suwandi S, Hasbi (2020) Exploring entomopathogenic fungi from South Sumatra (Indonesia) soil and their pathogenicity against a new invasive maize pest Spodoptera frugiperda. Biodiversitas 21(7):2955-2965. https://doi.org/10.13057/biodiv/d210711
Herrera-Téllez VI, Cruz-Olmedo AK, Plasencia J, Gavilanes-Ruíz M, Arce-Cervantes O, Hernández-León S, Saucedo-García M (2019) The protective effect of Trichoderma asperellum on tomato plants against Fusarium oxysporum and Botrytis cinerea diseases involves inhibition of reactive oxygen species production. Int J Mol Sci 20(8):2007. https://doi.org/10.3390/ijms20082007
Humber R (1997) Fungi: identification. In: Lacey LA (ed) Manual of techniques in insect pathology. Academic Press, San Diego, pp 153–185
Kamaruzzaman M, Rahman MM, Islam MS, Ahmad UM (2016) Efficacy of four selective Trichoderma isolates as plant growth promoters in two peanut varieties. Int J Biol Res 4(2):152–156
Karuppiah V, Sun J, Li T, Vallikkannu M, Chen J (2019) Co-cultivation of Trichoderma asperellum GDFS1009 and Bacillus amyloliquefaciens 1841 causes differential gene expression and improvement in the wheat growth and biocontrol activity. Front Microbiol 10:1068. https://doi.org/10.3389/fmicb.2019.01068
Kumar S, Stecher G, Tamura K (2016) MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. Mol Biol Evol 33(7):1870–1874. https://doi.org/10.1093/molbev/msw054
Li L, Zeng X, Chen J, Tian J, Huang J, Su S (2021) Genome sequence of the fungus Trichoderma asperellum SM-12F1 revealing candidate functions of growth promotion, biocontrol, and bioremediation. PhytoFrontiers 1(3):239–243. https://doi.org/10.1094/PHYTOFR-12-20-0052-A
Mohamed G (2019) The virulence of the entomopathogenic fungi on the predatory species, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) under laboratory conditions. Egypt J Biol Pest Control 29:42 https://doi.org/10.1186/s41938-019-0146-4
Mohamed B, Sallam N, Alamri S, Abo-Elyousr K, Mostafa Y, Hashem M (2020) Approving the biocontrol method of potato wilt caused by Ralstonia solanacearum (Smith) using Enterobacter cloacae PS14 and Trichoderma asperellum T34. Egypt J Biol Pest Control 30:61. https://doi.org/10.1186/s41938-020-00262-9
Moreira FM, Cairo PAR, Borges AL, da Silva LD, Haddad F (2021) Investigating the ideal mixture of soil and organic compound with Bacillus sp. and Trichoderma asperellum inoculations for optimal growth and nutrient content of banana seedlings. S Afr J Bot 137:249–256. https://doi.org/10.1016/j.sajb.2020.10.021
Navarez ML, Sangcopan R, Aryal S, Sumaya NPD, Bhat AH, Sumaya NH (2021) Native Philippine Heterorhabditis indica isolates from banana and rice fields and preliminary results of their virulence against the larvae of super worm (Zophobas morio Fabricius Coleoptera: Tenebrionidae). Egypt J Biol Pest Control 31:46. https://doi.org/10.1186/s41938-021-00388-4
Nylander JAA (2004) MrModelTest, 2.0. Upsalla, Distributed by the author: Evolutionary Biology Centre: Uppsala University, Uppsala
Ortiz-Hernández ML, Rodríguez A, Sánchez-Salinas E, Castrejón-Godínez ML (2014) Bioremediation of soils contaminated with pesticides: experiences in Mexico. In: Alvarez A, Polti MA (eds) Bioremediation in Latin America. Springer, Cham, pp 69–99. https://doi.org/10.1007/978-3-319-05738-5_5
Podder D, Ghosh SK (2019) A new application of Trichoderma asperellum as an anopheline larvicide for eco friendly management in medical science. Sci Rep 9:1108
Posada D (2008) jModelTest: phylogenetic model averaging. Mol Biol Evol 25(7):1253–1256. https://doi.org/10.1093/molbev/msn083
Poveda J (2021) Trichoderma as biocontrol agent against pests: new uses for a mycoparasite. Biol Control 159:104634. https://doi.org/10.1016/j.biocontrol.2021.104
Rambaut A (2018) FigTree. version 1.4.4. http://tree.bio.ed.ac.uk/software-/figtree/. Accessed 20 Aug 2019
Ronquist F, Teslenko M, van der Mark P, Ayres DL, Darling A, Höhna S, Huelsenbeck JP (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Syst Biol 61(3):539–542. https://doi.org/10.1093/sysbio/sys029
Samuels GJ, Lieckfelt E, Nirenberg HI (1999) Trichoderma asperellum, a new species with warted conidia and redescription of T. viride. Sydowia 51:71–88
Senkovs M, Nikolajeva V, Makarenkova G, Petrina Z (2021) Influence of Trichoderma asperellum and Bacillus subtilis as biocontrol and plant growth promoting agents on soil microbiota. Ann Microbiol 71:34. https://doi.org/10.1186/s13213-021-01647-3
Sood M, Kapoor D, Kumar V, Sheteiwy MS, Ramakrishnan M, Landi M, Sharma A (2020) Trichoderma: the “secrets” of a multitalented biocontrol agent. Plants 9(6):762. https://doi.org/10.3390/plants9060762
Vilcacundo E, Trillas MI, Carrillo W (2020) Trichoderma asperellum strain T34 used as biocontrol agent against Rhizoctonia solani in potato plants. Plant Pathol J 19:89–97. https://doi.org/10.3923/ppj.2020.89.97
Woo SL, Ruocco M, Vinale F, Nigro M, Marra R, Lombardi N, Pascale A, Lanzuise A, Manganiello G, Lorito M (2014) Trichoderma-based products and their widespread use in agriculture. Open Mycol J 8:71–126. https://doi.org/10.2174/1874437001408010071
Wu Q, Sun R, Ni M, Yu J, Li Y, Yu C, Chen J (2017) Identification of a novel fungus, Trichoderma asperellum GDFS1009, and comprehensive evaluation of its biocontrol efficacy. PLoS ONE 12(6):e0179957. https://doi.org/10.1371/journal.pone.017995
Acknowledgements
This research was funded by the Accelerated Science and Technology Human Resource Development Program-National Science Consortium (ASTHRDP-NSC) program of the Department of Science and Technology (DOST), with Master of Science in Biology scholarships to RS, KRG, MS, and CJA. Thanks are also due to Dr. Joey Genevieve Martinez and the MEP team for their kind assistance during our microscopy works. The work of AHB is supported by a Postdoctoral Swiss Government Excellence Scholarship (Grant Nr. 2021.0463 to AHB). The work of RARM is supported by the Swiss National Science Foundation (Grant Nr. 186094 to RARM).
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This research was funded by the Accelerated Science and Technology Human Resource Development Program-National Science Consortium (ASTHRDP-NSC) program of the Department of Science and Technology (DOST).
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RS, KRG, MS, CJA, and NHS conceptualized and designed the experimental work. RS, KRG, MS, CJA, PN, and NHS provided material. RS, KRG, MS, and CJA performed the field and laboratory experiments, RS collected and analyzed the data, under the supervision of NHS and advice of PN, AHB, and RARM. NHS was the in-charge of resources and supervision. RS wrote the manuscript together with NHS and with substantial input of all other authors. All authors agreed with the submission of the manuscript. All authors read and approved the final manuscript.
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Additional file 1: Fig. S1.
Amplicon products at 1% agarose with the DNA marker (1 Kb plus ladder, Invitrogen). Amplicons showed the good quality of single and intense band for each sample with 400–600 bp size target, were purified using Exosap IT to remove the unnecessary smears and other possible inhibitors.
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Sebumpan, R., Guiritan, K.R., Suan, M. et al. Morphological and molecular identification of Trichoderma asperellum isolated from a dragon fruit farm in the southern Philippines and its pathogenicity against the larvae of the super worm, Zophobas morio (Fabricius, 1776) (Coleoptera: Tenebrionidae). Egypt J Biol Pest Control 32, 47 (2022). https://doi.org/10.1186/s41938-022-00548-0
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DOI: https://doi.org/10.1186/s41938-022-00548-0