Mycelial Colony Growth Research Articles

Identification and Characterization of Endophytic Fungi from Garcinia atroviridis for Potential Antagonistic Against Phytopathogenic, Colletotrichum gloeosporioides

Biological control is referred to as the “use of natural or modified organisms, genes” to minimize the effects of undesirable pests, pathogenic microorganisms, and diseases on plant crops. This measure has become a suitable and safe alternative for chemical fungicides in plant disease management. Endophytic fungi have received much attention as biological control agents against many plant pathogens through antibiosis, parasitism, invading spores, mycelium, and cells of the pathogen, and secreting bioactive metabolites. While the therapeutic properties of Garcinia atroviridis have been studied, the existence of microbial endophytes and their properties is still less documented. In this research, G. atroviridis endophytic fungi were isolated and identified by fungal colony morphology observation combined with the PCR-amplified fungal internal transcribed spacer (ITS) sequence analyses. Fungal endophytes were assessed for their biocontrol potential against Colletotrichum gloeosporioides. In total, 111 endophytic fungal isolates harboring inside the leaf, branch, and fruit of G. atroviridis belonged to 5 different species with 3 different genera and two unidentified genera. All the endophytic fungal species isolated were evaluated using an in vitro dual culture assay against C. gloeosporioides, a common pathogen that causes anthracnose disease. The results of the present study clearly showed that seven species of isolated fungal endophytes were capable of inhibiting the mycelial colony growth of C. gloeosporioides with an inhibition percentage between 54.67% to 87.94%. Among these species, Nigrospora sphaerica recorded the highest PIRG with 87.94%. Our work indicates that endophytic fungi isolated from G. atroviridis have a biocontrol effect on C. gloeosporioides and are expected to be a potential source of bioactive metabolites.

Studi Pertumbuhan Miselia Jamur Merang (Volvariella volvaceae) G2 Isolat FP005 Faperta UNSIKA Pada Beberapa Bahan Alternatif Media In Vitro

Straw mushroom is one of the horticultural commodities that is in great demand by the community. The successful cultivation of straw mushrooms is determined by the quality of the seeds of the molten mushroom. Tissue culture is one of the efforts to get quality seeds. Quality seedlings are seen from the brood of the merang fungus and the quality of pure culture. Making pure culture is still constrained in making in vitro media, especially alternative media materials. This study aims to obtain the best results from the growth of G2 FP005 mycelia on alternative media materials in vitro. This research was conducted at the Biotechnology and Plant Breeding Laboratory, Faculty of Agriculture, Singaperbangsa University, Karawang from April to May 2023. The research method used was a single factor Complete Randomized Design (CRD) with 7 treatments and 5 replications: A (100% PDA); B (100% Charcoal Husk Solution); C (100% Husk Solution); D (80% PDA + 20% Husk Charcoal Solution), E (75% PDA + 25% Husk Solution), F (50% Husk Charcoal Solution + 50% Husk Solution); G (50% PDA + 25% Husk Charcoal Solution + 25% Husk Solution). The effect of the treatment was analyzed using variance and if the F test was significant at 1% level, then to find out which treatment was the best it was continued with the DMRT (Duncan Multiple Range Test) advanced test at the 1% level of significance. The results achieved from this study were that there was a significant effect of using alternative media materials on the growth of the straw mushroom mycelia. Alternative media 80% PDA + 20% rice husk charcoal gave the highest mycelia colony diameter of 7.88 cm and the highest mycelial colony growth rate of 2,878 cm/day. Keywords: Unsika Faperta Isolate, Straw Mushroom, Tissue Culture.

In vitro efficacy of fungal endophytes and silver pyrazolate against Raffaelea lauricola, causal agent of laurel wilt of avocado

The South Florida avocado industry is being severely impacted by laurel wilt disease. Laurel wilt disease of avocado is caused by the fungal pathogen, Raffaelea lauricola (RL) and is vectored by ambrosia beetle, Xyleborus glabratus. Treatments options are limited, economically not sustainable, and require reapplication fungicides every couple of years. There is a crucial need for developing multiple modes of control using novel biological and chemical agents. The ambrosia beetle associated pathogenic fungi are known to outcompete other microorganisms by taking advantage of ethanol produced by the pathogen and the stressed tree. Endophytes, which reside inside the host plant tissue are part of the plant microbiome represent source of new potential biological control agents. In this study, three ethanol tolerant endophytic fungal species, isolated from avocado bark, were evaluated using in vitro dual culture assay and colonization tube (packed with bark/sapwood shaving) against RL. The endophytic isolates Tricoderma crissum, Tricoderma simmonsii, Lasiodiplodia theobromae were found to be highly capable of suppressing the mycelial colony growth of RL. The results suggest that combined abilities of ethanol tolerance and competitive colonization can provide useful criteria for identifying potential biocontrol agents. In vitro anti-RL activity of silver pyrazolate compound was assessed in both agar and liquid medium. Silver pyrazolate at levels of 30 and 45 ppm were found to be highly effective against RL. Further in planta research is needed to study the effects of endophytic fungal isolates and silver pyrazolate to assess their potential as additional tools for management of laurel wilt.

EVALUATION OF DIFFERENT FUNGICIDES, BOTANICAL EXTRACTS AND BIOCONTROL AGENTS AGAINST ALTERNARIA ALTERNATA THE CAUSAL AGENT OF LEAF SPOT IN SPINACH

Alternaria disease is among the most important diseases of Spinach throughout the world. They affect primarily the leaves. Alternaria spp. is major plant pathogens, which cause at least 20% of agricultural spoilage most severe losses may reach up to 80%.This study was carried out to study the in-vitro efficacy of different fungicides, botanical extracts and bio-control agent against leaf spot disease of spinach caused by Alternaria alternate. Cabrio top showed minimum mycelial colony growth (23, 21 and 17 mm) at various concentrations 100, 200 and 300 ppm, respectively, followed by Topsin-M (44.5, 33 and 19 mm), Melodyduo (33, 26.5 and 22.5 mm), Prevail (43.5, 37 and 22.5 mm) and Antracol (41, 33 and 24 mm) at various concentrations 100, 200 and 300 ppm, respectively. However, in control, the mycelial colony growth of A. alternata causing leaf spot disease was recorded as 90 mm at 100, 200 and 300 ppm concentrations. Minimum mycelia colony growth (43, 35 and 15 mm) was recorded at 5, 10 and 15% concentration for Aak followed by Garlic (43.5, 33 and 20 mm), Neem (49, 38.5 and 23 mm), Onion (57.4, 50.25 and 27.65 mm) and Eucalyptus (57.9, 51.4 and 33.45 mm) and maximum mycelial colony growth (90.00 mm) were recorded in control. Minimum mycelial colony growth of A. alternata was observed for Neurospora spp. (47.00 mm) followed by Hypocrea sp. (48.00 mm), Lasodiplodia sp. (49.5 mm), Fusarium sp. (57.5 mm) and Chactomium sp. (57.5 mm). Maximum mycelial colony growth (90 mm) was recorded in control.

EVALUATION OF DIFFERENT ESSENTIAL OILS AND BIO CONTROL AGENTS AGAINST ALTERNARIA ALTERNATA THE CAUSAL AGENT OF FRUIT ROT OF JUJUBE

This study was carried out on the evaluation of different essential oils and biocontrol agents against Alternaria alternata the causal agent of fruit rot. For the pathogenicity test against A. alternata was performed through cut and injection inoculation methods. The antifungal potential of different essential oils like turpentine, laung, neem and castus root was carried out at different doses i.e. 5, 10 and 15% by food poisoned method to find out the effective and suitable oil for the growth inhibition of A. alternata and evaluate the effect of some biocontrol agents on growth inhibition of A. alternata. The findings of this investigation stated that cut method of inoculation showed higher percentage (2.60) of rotting as compared to injection method of inoculation (2.35). Minimum colony growth of A. alternata (31.60, 21.25 and 15.16%) was examined under Laung oil at the dosage of 5, 10 and 15% followed by Neem oil (42.60, 31.60 and 21.30%), respectively. Maximum colony growth of A. alternata (62.71, 52.40 and 41.75%) was observed under Castus root oil at the dosage of 5, 10 and 15%. Zero growth of target pathogen was examined under Turpentine at 5, 10 and 15%. Under control the A. alternata showed (90 mm) colony growth. Minimum linear colony growth of A. alternata was observed for Hypoxylon Sp1 (50.31%), followed by Neurospora spp. (52.97%), Lasiodiplodia theobromae (54.7%), Chactomium subaffine (57.07%) and Fusarium sp. (65.4%). Maximum mycelial colony growth (90%) was recorded in control. Based on present investigation, Similarly, for controlling the linear colony growth of A. alternata under in vitro conditions Turpentine oil ranked 1st, Laung oil ranked 2nd, Neem oil ranked 3rd, Castus root oil ranked 4th.

Disease intensity and eco-friendly management of Alternaria alternata in chili (Capsicum annuum L.)

Fruit rot of chili caused by Alternaria alternata is the most commonly occurring fungi affecting the crop. Present study was carried out on survey, intensity and management of causal fungus of chili fruit rot. The chili fruit rot incidence during the survey of fields/commercial markets carried out in the surroundings of Hyderabad, Mirpur Khas, Tando Allahyar and Umer Kote districts was ranged from 14.33-36.66 %. On overall basis Umer Kote district revealed significantly highest (31.44%) fruit rot incidence compared to Tando Allahyar (26.89%) and Hyderabad (26.56%). However, it was lowest in Mirpur Khas (19.00%). Among the 12 different locations (villages and markets) from four major chili growing districts, maximum incidence of chilli fruit rot was recorded at Sultanabad (36.66%) followed by Village Mustafa Arain (35.33%), whereas, the minimum fruit rot incidence (14.33%) was observed at Khawaja Village followed by Dah hoti (18.66%). All the 22 tested botanical treatments gave inhibitory effects; however, significantly lowest radial mycelial colony growth and greatest reduction of A. alternata was induced by extract from Amomum subulatum (22.94mm and 74.51%) followed by Azadirachta indica seed (24.15mm and 73.16%).The maximum radial mycelial colony growth and lowest reduction of A. alternata was recorded in control (90.00mm and 00.0%) followed by the extract from Syzygium aromaticum (66.17mm and 26.48%).The efficacy of other tested botanicals remained moderate. Hence several botanical extracts which are more effective in suppressing chilli fruit diseases caused by A. alternata may be commercially prepared and used for integrated chilli fruit rot management, with a hope that it will be helpful for the end users. Keywords: Amomum subulatum; Botanical extracts; Chili fruit rot; Fungus http://dx.doi.org/10.19045/bspab.2019.80180

Biocontrol Potential of Fungal Endophytes against Fusarium oxysporum f. sp. cucumerinum Causing Wilt in Cucumber.

Endophytic fungi have received much attention as plant growth promoters as well as biological control agents against many plant pathogens. In this study, 30 endophytic fungal species, isolated from various plants in China, were evaluated using in vitro dual culture assay against Fusarium oxysporum f. sp. cucumerinum, causing wilt in cucumber. The results of the present study clearly showed that all the 30 endophytic fungal isolates were highly capable of inhibiting the mycelial colony growth of Fusarium oxysporum f. sp. cucumerinum with inhibition % over 66% as compared to control treatments. Among all of them, 5 isolates were highly effective such as, Penicillium sp., Guignardia mangiferae, Hypocrea sp., Neurospora sp., Eupenicillium javanicum, and Lasiodiplodia theobromae, respectively. The Penicillium sp. and Hypocrea sp. were highly effective as compared to other isolates. From in vitro results 10 best isolates were selected for greenhouse studies. The results of the greenhouse studies showed that among all of them 3 endophytic fungal isolates successfully suppressed wilt severity when co-inoculation with pathogen Fusarium. oxysporum f. sp. cucumerinum. The endophytic fungi also enhanced plant growth parameters of the host plants, the antagonistic fungal isolates increased over all plant height, aerial fresh, and dry weight as compared to control.

In-vitro efficacy of bio-control agent and essential oils against leaf blight of chickpea caused by Alternaria alternata

Alternaria leaf blight is one of the most destructive foliar diseases of chickpea in different countries including Pakistan and has caused huge losses ranging from 5 to 100% around the world. This study was carried out to check the in-vitro effectiveness and sustainability of a bio-control agent Trichoderma viride and some essential oils like Castor, Jasmine, Clove, Sesame, Neem, Coconut, Henna, Black seed, and Mint oil at different doses of 1%, 2%, 4%, and 6% by food poisoned method against the mycelial colony growth inhibition of A. alternata which causes leaf blight in chickpea. The results indicate that maximum germination (80%) was recorded in control, (63%) under soil infestation and a minimum germination of (60%) was recorded in seed infestation. Maximum shoot weight (0.5630 g) in control, (0.2751 g) under soil infestation and (0.2064 g) in seed infestation. Maximum root weight (0.5937 g) in control, (0.4359 g) under soil infestation method, and (0.4102 g) in seed infestation method. Maximum shoot length (20.00 cm) in control, (10.23 cm) under soil infestation method and (7.053 cm) in seed infestation method. Maximum root length (7.19 cm) in control, (4.80 cm) under soil infestation method and (4.80 cm) in seed infestation. Bio-control agent Trichoderma viride showed (74.44%) growth inhibition compared to control (1.00%) growth inhibition of A. alternata. Maximum colony growth inhibition of A. alternata was (80.00%) Sesame, Coconut (77.04%), Henna (72.59%), Mint (66.07%), Black seed (71.85%), Jasmine (64.07%), Clove (70.74%), Neem (73.33%), Castor (58.89%) and minimum of (1.00%) was recorded in control. The results of this study will be very helpful for researchers and farming community for better management of this destructive disease of chickpea.

Effect of selected fungicides and Bio-Pesticides on the mycelial colony growth of the Helminthosporium oryzae. brown spot of rice

Helminthosporium oryzae, a fungal pathogen causing Brown Spot of Rice is one of the disastrous biotic factors responsible for 16–43% yield in rice. To control in vitro fungal growth of this pathogen, four fungicides viz. Mencozeb, Thiophanate Methyl, Iprovalicarb + Propineb and Propineb were used with four different concentrations: 50, 100, 150 and 200 ppm. Plant extracts of five species as Azadirachta indica, Calotropisprocera, Allium sativum, Datura stramonium and Zingiber officinale were also tested with three doses (5, 10 and 15 ml). While, 24 isolates of Bacterial isolates were investigated for their antagonistic effect. The in vitro results of the four fungicides contributed that Mancozeb and Thiophanate Methyl inhibited the colony growth at the higher doses (150 and 200 ppm) with no linear colony growth. However, Propineb was found moderately effective at (5.00 mm) and Iprovalicarb + Propineb was less effective (7.25 mm). Similarly, the in-vitro efficacy of the five plant extracts against H. oryzae at different doses revealed that Zingiber officinale and Allium sativum were more effective at high doses (00.00 mm, 2. mm). Also, Datura stramonium (4.62 mm) Azadirachta indica (18.00 mm) and Calotropisprocera (12.00 mm) performed better as compared to the control (40.00 mm). The results revealed that out of 24 isolates, 4 isolates of bacteria Agrobacterium spp, Xanthomonas, Erwinia, Streptomyces has inhibited the linear colony growth of H. oryzae up to 1-2 mm. This study can be useful for controlling the fungal disease as the two fungicides Mancozeb and Thiophanate Methyl were more effective and the Zingiber officinale and Allium sativum plant extracts were highly effective against the brown spot of rice. Biocontrol also reduced leaner colony Helminthosporium oryzae.

Utilizing Soybean Milk to Culture Soybean Pathogens

Liquid and semi-solid culture media are used to maintain and proliferate bacteria, fungi, and Oomycetes for research in microbiology and plant pathology. In this study, a comparison was made between soybean milk medium, also referred to as soymilk, and media traditionally used for culturing soybean pathogens to determine if soymilk medium was an effective medium for growth of Colletotrichum truncatum, Fusarium virguliforme, Macrophomina phaseolina, Passalora sojina, Phomopsis longicolla, Phytophthora sojae, Pythium irregulare, Rhizoctonia solani, and Sclerotinia sclerotiorum. Based on radial mycelial colony growth rates, C. sojina grew significantly (P C. truncatum and F. virguliforme grew significantly (P P S. sclerotiorum grown on SDA as compared to PDA. Soymilk used with agar or used alone as a broth may be an option for replacing more expensive processed culture media.

Effect of heat shock on protein synthesis in flax rust uredosporelings

In uredosporelings of Melampsora lini (Ehrenb.) Lév. germinated for 3 h, uptake of [35S]methionine and its incorporation into protein were depressed during a 2-h heat shock induced by transfer from 17 ± 0.5 to 31 °C. Spectrophotometric scans of fluorograms, prepared after one-dimensional sodium dodecyl sulphate – polyacrylamide gel electrophoresis of aliquots of protein extracts containing equal numbers of disintegrations per minute (1 dps = 1 Bq) in protein, showed that heat shock induced statistically significant changes in the relative degrees of incorporation of [35S]methionine into 15 polypeptide bands. Increased labelling occurred in seven bands, which appear to be heat shock proteins with apparent molecular masses of 84, 71, 43.5, 30.5, 19.5, 18, and 17 kD. Decreased labelling occurred in eight bands, which appear to be heat stroke proteins with apparent molecular masses of 56, 54, 48, 46, 34, 32, 31.5, and 14 kD. When [35S]methionine was administered during heat shock at 31 °C the same pattern of polypeptide labelling was observed in extracts made immediately without return to 17 °C and in extracts made after uredosporelings were returned to 17 °C for 24 h. Thus label incorporated into each polypeptide during heat shock was retained for at least 24 h after the return to 17 °C. Administration of [35S]methionine at 17 °C after completion of the heat shock showed that the "normal" or "nonshock" pattern of labelling began to be resumed within 2 h after transfer from 31 to 17 °C. The results are discussed in relation to the effect of heat shock in promoting the initiation and growth of mycelial colonies from uredosporelings in axenic culture.

Brown Leaf Spot of Physocarpus spp. Caused by Cercospora spiraeicola Muller et Chupp

The Cercospora causing brown leaf spot of Physocarpus spp. in Japan was identified as C. spiraeicola Muller et Chupp on the basis of their identical morphological characteristics. Among the inoculated plants belonging to Spiraeaceae, the fungus infected Physocarpus amurensis and P. opulifolius, but not Spiraea spp., Stephanandra spp. and Sorbaria kirilowii, even though, C. spiraeicola had been described on Spiraea prunifolia. Conidia of the fungus overwinter on the fallen diseased leaves. They keep well their germination ability throughout winter and serve as the primary infection source from May to June. Incubation period of the fungus is about two months in spring and one month in summer and early autumn. The fungus may not overwinter within winter bud on the diseased bushes. Conidia germinate and mycelial colonies grow at 10∼35C with optimum temperature of 25∼30C. They germinate well under atmospheric humidity above 98%. H-ion concentration has no influence on not only germination of conidia except pH 3, but also growth of mycelial colonies. Colonies of the fungus grow well on malt extract, potato-sucrose, Saito's soy and Waksman's solution agar.