Seed-borne Fungi Research Articles

Fungitoxic effects of some plant extracts on seedborne fungi pathogens of Bambara groundnut in Awka South of Anambra State, Nigeria

Fungitoxic effects of some plant extracts on seedborne fungi pathogens of Bambara groundnut in Awka South of Anambra State, Nigeria

Effectiveness of pulsed radio frequency in seed quality improvement of vegetable plant species

The biggest problem, in ecological vegetable seed production, is low germination mostly caused by high seed infection with fungi and a shortage of effective biological agents eliminating pathogens. Therefore, pro-ecological methods of seed quality enhancement are being searched, increasing the profitability of seed production by improving the seed sowing value. The aim of the work was to evaluate the effectiveness of pulsed radio frequency (PRF) on seed quality of selected vegetable cultivars. The obtained results from conducted research in laboratory, greenhouse and field conditions indicate a protective effect of PRF treatment by reduction of beetroot, lettuce and garden dill seed-borne fungi, and the improvement of their health status and seed germination. Pre-sowing application of PRF resulted in 60-80% reduction of seed infestation with fungi, depending on the plant species. This treatment improved the dynamics of seed germination, plant emergence, growth, and increased chlorophyll content and gas exchange in leaves. The most beneficial results were obtained in beetroot, in which the problem of seed production is associated with high seed infestation with mycoflora and the presence of germination inhibitors in the seed coat. The results indicate the high efficiency of the applied PRF and its usefulness in ecological and integrated seed production.

Screening and interaction between pathogens and antagonistic seed-borne fungi, associated with some organic spices and vegetable crops in Tunisia

Seed-borne pathogenic and antagonistic fungi were isolated from the same organic vegetable and spice seeds (carrot, fennel, broad bean, faba bean, and lettuce), and the interaction between them were studied as a part of a biocontrol assay. In vitro dual culture assay between each pathogen and the antagonists on PDA medium was made, which led to the inhibition of the pathogens mycelial growth. According to results generated for fennel seed-borne fungi, direct confrontation of the five pathogens (Botrytis cinerea, Sclerotinia sclerotiorum, Cladosporium cladosporiodes, Cladosporium link and Bispora sp.), with Aspergillus niger and Penicillium digitatum showed an inhibition of radial growth above 50%. For lettuce; the highest inhibition was recorded by Trichoderma harzianum in confrontation with S. sclerotiorum, and P. digitatum in confrontation with Alternaria alternata. For carrot, three fungal pathogens were identified as: A. alternata, A. solani and Pythium sp., which were faced with three antagonists (P. chrysogenum, A. niger and T. harzianum), and showed radial inhibition about 50%. Concerning broad bean and baba bean; only A. alternta was isolated, and has been confronted with T. harzianum, P. digitatum, and P. italicum. During in vivo assays on fennel plant in the greenhouse; a disease severity index caused by various pathogens alone and in combination with antagonists compared to control plants, was recorded. According to results observed, fennel plants inoculated with B. cinerea and treated curatively with P. digitatum and preventively with A. niger; recorded a low disease severity index value of 0.22. This work was carried out to find effective seed-borne bioagents that could cause in vitro and in vivo inhibition of the growth of several fungal pathogens of vegetables; thus could be applied in the field for the biocontrol of fungal spice and vegetable crops diseases.

Antifungal activities of <i>Carica papaya</i> and sodium bicarbonate against Soybean fungi

Soybean ( Glycine max (L.) merr.) is a well-known leguminous crop serving as a principal protein rich food source for human and livestock. The study examined the antifungal efficacy of sodium bicarbonate (NaHCO 3 ) and Carica papaya on fungi isolated from soybean seeds. The inhibitory effects of sodium bicarbonate (NaHCO 3 ) and leaf extracts of Carica papaya were tested on three fungi. In vitro studies were carried out on Potato Dextrose Agar (PDA) for fungal isolation from soybean seeds and for the control of the pathogens using NaHCO 3 and C. papaya. The results obtained were compared with benlate (a.i 50% Benomyl); a synthetic fungicide. Aspergillus niger had the highest percent occurrence (50%) followed by F. ventricosum (33%) and then B. theobromae (17%). The percent fungal inhibition was highly significant at 1% level of probability, indicating that all the antifungal agents exhibited broad spectrum inhibition against the isolates. Benlate completely (100%) inhibited the three pathogens. There was no significant difference (P ≤ 0.05) in the inhibition of A. niger at 1.54 mg/ml of C. papaya and 3 mg/ml of NaHCO 3 . Fusarium ventricosum and B. theobromae were best inhibited at 1.54 mg/ml of C. papaya with mean values of 95.63% and 95% respectively. A positive and significant correlation occurred between the inhibitions of all the fungal isolates. This implies that all the antifungal agents are capable of inhibiting the three fungal isolates. The study suggests that C. papaya and NaHCO 3 are capable of controlling seed-borne pathogens in soybean seeds. Keywords : Antifungal agents, inhibition, leaf extract, mycelia growth, seed-borne fungi.

Effect of Microwave Radiation on Internal Inoculum of Ascochyta Blight in Lentil Seeds at Different Seed Moisture Contents

Abstract. Considering the development of pest and pathogen resistance to chemical treatments and the cost of developing new chemicals, proper physical methods for integrated pest management seem to be gaining interest. Microwave treatment has been considered a potential postharvest pest and disease management strategy in legume and grain seeds. The effect of this process on pathogens related to legumes, which could be expressed as a very fast and volumetric thermal treatment, has not been fully studied. In this study, a domestic microwave oven with full output power of 1100 W (company information) or 485 W (calibrated with 150 g of water) was used to treat red lentil seeds that were naturally infected with the Ascochyta blight (AB) pathogen, a problematic seedborne fungi of lentil. Microwave radiation was applied at three moisture contents of red lentil seeds (9.1%, 16%, and 19% wet basis) and two power levels (50% and 100%). Three exposure times for each moisture content and power level were selected to achieve the same final average temperatures with low and high moisture contents (approx. 65°C to 85°C). The complementary error function was used to model and compare the pathogen and seed death rates based on the normally distributed susceptibility of the AB pathogen and seed germination to microwave heating. At 9% moisture content with water activity of 0.4, the percentage of infected seeds decreased from 17% to 9% without significant loss of seed viability when a power level of 100% (9.7 W g-1) and exposure time of 51 s were applied, and the final average surface temperature reached 84°C. However, seed vigor, measured by the electrical conductivity of the seed leachate, decreased at this power level and exposure time. Despite the feasibility of fungi elimination at higher moisture content at the same final average temperatures, eliminating fungi from the seeds without harming their viability and vigor was challenging. Keywords: Ascochyta blight, Lentils, Microwave energy, Pathology.

Prevalence of seed-borne fungi of different vegetables seeds in Bangladesh

Prevalence of seed-borne fungi of different vegetables seeds in Bangladesh

Diversity of seed borne fungi associated with fourteen varieties of storage cotton (Gossypium hirsutum L.) seeds

Present paper deals with the occurrence and diversity of fungi on storage cotton (Gossypium hirsutum L.) seeds. 24 species of the fungi were found associated with the seeds of 14 varieties of cotton after 10 months of storage. The isolated fungi were Aspergillus flavus Link, A. fumigatus Fresenius, A. niger (Type 1 and Type 2) Van Tiegh, A. ochraceus K. Wilhelm, A. nidulans Eidam, Aspergillus sp.1, Aspergillus sp.2, Aspergillus sp.3, Curvularia lunata (Wakker) Boedijn, Colletotrichum gloeosporioides Penz & Sacc, C. gossypii Southw., Chaetomium globosum Kunze., Fusarium nivale (Fr.) Sorauer, F. moniliforme J. Shelden, F. oxysporum Schlechtendal, F. fujikuroi Nirenberg, Mucor sp. P. Micheli ex L., Penicillium sp.1 and sp.2 Link, Rhizoctonia solani Khun., Rhizopus stolonifer (Ehrenb.) Vuill., Rhizomucor Lucet & Costantin, Syncephalastrum racemosum Cohn and Trichoderma viride Pers. The association of fungi with cotton seeds was recorded within two months of harvest, after 6 and 10 months of storage. The association of fungi varied with duration of storage periods. Aspergillus flavus, A. fumigatus, A. niger, Chaetomium globosum, Penicillium sp.1 and Rhizopus stolonifer were found in all the examined varieties. These were the most predominant fungi in terms of prevalence with the increase of storage periods. The fungal association with the seeds of cotton also affected the germination, seedling mortality, height and vigor. The total association of fungi in cotton seeds was the highest in cotton variety CB10 (204) and the lowest in CB8 (71). On the other hand, the total fungal association of Rhizopus stolonifer was the highest (337) and Colletotrichum gossypii was the lowest (1).
 J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(2): 43-52

EFFICACY OF HERBAL POWDERS ON SEED MYCOFLORA AND SEED QUALITY OF OILSEEDS

ABSTRACT The present study involved seed health testing of four oil seeds (mustard, niger, groundnut and sunflower) for seed-borne fungi and seed vigor, and the evaluation of neem and tulsi leaf powders as seed treatment biofungicides. Standard blotter, agar plate and paper towel methods were employed. All the seed samples tested yielded several seed borne fungi. The herbal powders were screened individually and in combination (1:1) at the concentrations of 2, 5 and 10% by seed treatment. The incidence of seed borne fungi from oilseeds was substantially reduced by neem and tulsi powder on seed treatment in comparison to untreated control seeds. The leaf powders also increased seed germination and seedling emergence with increased shoot and root length. These plant powders could possibly be exploited in the management of seed-borne pathogenic fungi to prevent deterioration of oil seeds and to increase their vigor in an eco-friendly way.

Prevalence of Seed Borne Fungi Associated with Chickpea Seeds and Biological and Chemical Control of Fusarium oxysporum Causing Wilt Disease

A total of 20 chickpea seed samples were collected from BARI, Gazipurand different locations of Savar, Dhaka district. Blotter method was used for detection of the associated fungi of chickpea seeds. Altogether 14 fungi comprising 12 genera namely Aspergillus flavus, Aspergillus niger, Aspergillus sp, Botryodiplodia theobromae, Botryti cinerea, Curvularia lunata, Chaetomium globosum, Cladosporium sp., Colletotrichum dematium, Fusarium oxysporum, Macrophomina phasaelina, Rhizoctonia solani, Rhizopus stolonifer and Stemphylium sarciniforme were isolated from chickpea seed samples. Among the fungi isolated fungi, F. oxysporumwas most prevalent with an average incidence of 18.95% and found in all the seed samples. The germination of seed samples varied from 55-90 % on blotter. The pathogenic fungi and other storage fungi like Aspergillus caused lower the germination of the seeds.A pathogenicity test was conducted with 20 isolates of F. oxysporum against their origin of chickpea seed samples in pot culture. The pathogenecity ranged from weak to highly pathogenic. The isolates FO 19, FO 17, FO 11 and FO 18 were highly virulent. The isolates FO 9, FO10 and FO 15 were virulent and rest of the isolates were moderately virulent. The isolates FO 2 and FO 3 were weak pathogen.J. Environ. Sci. & Natural Resources, 10(2): 45-54 2017

In-vitro antimicrobial and antioxidant activity of Argyreia cuneata (Willd.) Ker Gawl. (Convolvulaceae)

Objectives: Argyreia cuneata (Willd.) Ker Gawl. belongs to the family Convolvulaceae. The present study was performed to screen the potential of crude extract of various parts of A. cuneata to exhibit antimicrobial activity. Methods: Extraction of shade dried and powdered leaf, stem and flower of A. cuneata was carried out by maceration technique. Antibacterial and antifungal activity of extracts was evaluated by Agar well diffusion and Poisoned food technique respectively. Antioxidant activity was determined by DPPH radical scavenging, ABTS radical scavenging and ferric reducing assays. Results: All extracts were effective in inhibiting test bacteria and the susceptibility of bacteria to extracts was in the order: Bacillus cereus > Shigella flexneri > Escherichia coli > Salmonella typhimurium. Leaf extract and stem extract exhibited highest and least antibacterial activity, respectively. Extracts were effective in causing inhibition of seed-borne fungi viz. Aspergillus niger and Bipolaris sp to >50%. Leaf extract exhibited marked antifungal activity followed by flower extract and stem extract. All extracts were shown to exhibit concentration dependent scavenging and reducing activity. Antioxidant activity of extracts observed was in the order: leaf extract > flower extract > stem extract. Conclusion: Among various parts of A. cuneata, leaf extract exhibited marked antimicrobial and antioxidant activity. The plant can be employed as an effective antimicrobial and antioxidant agent in suitable form. Further studies may be undertaken to recover phytochemicals from the plant and to investigate the antimicrobial and antioxidant activity of isolated components.
 Keywords: Argyreia cuneata, Maceration, Antimicrobial, Agar well diffusion, Poisoned food technique, Antioxidant

Deteksi Cepat Fusarium sp. pada Benih Kedelai Menggunakan Metode Spektroskopi Fluoresens

Rapid Detection Method for Fusarium sp. on Soybean Seed Using Fluorescence Spectroscopy MethodSeed borne pathogens play an important role as source of inoculum for disease in the field. Seed health testing is applied in order to prevent risks caused by seed borne pathogen. Fluorescence spectroscopy is a potential technology to be used as detection method for seed borne pathogen. Research was conducted to develop rapid detection protocol for seed borne pathogenic fungus by fluorescence spectroscopy method. The result showed that fluorescence spectroscopy could detect fluorescence emission of metabolite of Fusarium sp. after soybean seeds were incubated for 24 hr. Metabolite of Fusarium sp. produced cyan fluorescent at peak wavelength emission 504 nm when excited to violet light (405 nm). Fusarium sp. displayed typical fluorescence emission spectra which differ from fluorescence emission spectra of growth medium potato dextrose broth (PDB) (502 nm). It was evidenced that fluorescence spectroscopy method can be used to detect pathogenic seed borne fungi.

Antioxidant and antifungal activity of Geophila repens (L.) I. M. Johnst. (Rubiaceae)

Objectives: The present study was conducted to investigate the potential of leaf extract of Geophila repens (L.) I.M. Johnst. (Rubiaceae) to exhibit antioxidant and antifungal potential.
 Methods: Extraction of powdered leaf material was carried out by maceration process using methanol. Antioxidant activity of leaf extract was assessed by DPPH free radical scavenging assay and ferric reducing assay. Antifungal activity of leaf extract was determined by Poisoned food technique.
 Results: Leaf extract was shown to scavenge DPPH radicals dose dependently with IC50 value of 51.39µg/ml. An increase in the absorbance on increasing concentration of leaf extract indicated ferric reducing activity. The extract showed more or less similar inhibitory activity against Aspergillus niger and Bipolaris sp. (>50% inhibition).
 Conclusion: The results of the study indicate that leaf extract possesses bioactive principles with activity against oxidative damage and seed-borne fungi which are to be purified and screened for antioxidant and antifungal activity.
 Keywords: Geophila repens, Maceration, DPPH, Ferric reducing, Seed-borne fungi, Poisoned food technique

Antibacterial, antifungal and antioxidant activity of Dichapetalum gelonioides (Roxb.) Engl. (Dichapetalaceae)

Objectives: Dichapetalum gelonioides (Roxb.) Engl. belongs to the family Dichapetalaceae. In the present study, we investigated antibacterial, antifungal and antioxidant activity of methanolic extract of leaf and fruit of D. gelonioides.
 Methods: Maceration process was carried out for extraction of leaf and fruit of D. gelonioides. Agar well diffusion method was employed to evaluate antibacterial activity of extracts against gram positive and gram negative bacteria. Poisoned food technique was performed to investigate antifungal activity of extracts against two seed-borne fungi. Antioxidant activity was evaluated by DPPH radical scavenging and ferric reducing assays. 
 Results: Both leaf and fruit extracts were effective in causing inhibition of all test bacteria. Highest and least inhibitory activity was observed against Bacillus cereus and Escherichia coli respectively. Both Aspergillus niger and Bipolaris sp. were inhibited to >50% by leaf and fruit extracts. Extent of inhibition of Bipolaris sp. was slightly higher when compared to A. niger. Both leaf and fruit extracts showed a dose dependent scavenging of DPPH radicals with high activity being showed by leaf extract. Leaf extract was shown to exhibit marked reducing potential than fruit extract.
 Conclusions: Overall, leaf extract was shown to be more effective in displaying antioxidant activity and causing inhibition of bacteria and fungi when compared to fruit extract. The results indicate that the plant possess active principles which are to be purified, characterized and subjected for antimicrobial and antioxidant assays in further studies.
 Keywords: Dichapetalum gelonioides, Maceration, Agar well diffusion, Poisoned food technique, DPPH, Ferric reducing

Chitosan and yeast elicitor in suppressing seed-borne fungi of cucurbitaceous vegetables

Experiments were conducted under laboratory condition to examine the efficacy of Chitosan and Yeast Elicitor to suppress the growth of seed-borne fungi of cucurbitaceous vegetables. Seeds of bottle gourd, sweet gourd, snake gourd, wax gourd and cucumber were collected from seed traders of Mymensingh districts and different seed borne fungi were isolated, purified and identified. Fourteen fungal species belonging to twelve genera consisting of Aspergillus flavus, Aspergillus niger, Botrytis cinerea, Fusarium moniliforme, Fusarium oxysporum, Phoma exigua, Rhizopus stolonifer, Macrophomina phaseolina, Penicillium spp., Curvularia lunata, Chaetomium spp., Colletotrichum spp., Cercospora spp. and Alternaria alternata were isolated and identified. Four concentrations of Chitosan and Yeast Elicitors solutions (200, 500, 1000 & 2000 ppm) including one positive control Vitavax-200 WP (0.35%) were evaluated for controlling seed-borne fungi. Among the seed treating agents Chitosan (2000 ppm) and Yeast Elicitor (2000 ppm) showed better performance in suppressing the seed-borne fungi. Chitosan (2000 ppm) showed superior performance than Yeast Elicitor (2000 ppm). Results from the present study revealed that application of elicitors as seed treatment is a potential alternative of chemical fungicide for selective vegetables.J. Bangladesh Agril. Univ. 16(2): 187-192, August 2018

Effects of non–thermal plasmas on seed-borne Diaporthe/Phomopsis complex and germination parameters of soybean seeds

Abstract Diaporthe/Phomopsis (D/P) is a complex of seed-borne fungi that severely affects soybean (Glycine max (L.) Merrill), one of the most important crops worldwide. Non-thermal plasma treatment is a fast, economic and ecological friendly technology that can destroy seed-borne fungi and improve seed quality. Soybean seeds were exposed for 1, 2 and 3 min to a quasi-stationary (50 Hz) dielectric barrier discharge plasma operating at atmospheric pressure air. Different carrying gases (O2 and N2) and barrier-insulating materials were used. In this work we focused on the ability of plasma to control D/P in soybean seeds and to enhance seed quality. To support these results, different antioxidant enzymes (catalase, superoxide dismutase and guaiacol peroxidase), lipid peroxidation and phytohormones (ABA and AIA) content in seeds were evaluated. The results demonstrated reductions of 29% in catalase activity and increments of 30% in glutathione content after plasma treatment, reversing the oxidative damage caused by D/P fungi. This eco-friendly technology improved soybean seed quality and, for the first time, its efficiency in controlling soybean seed-borne pathogen fungi that colonize the inside of seeds was demonstrated.

Evaluation of seed-borne fungi associated with tomato and their control measures

A number of seed borne fungi such as- Fusarium moniliforme, Curvularia lunata, Alternaria solani, Helminthosporium solani, Aspergillus flavus, A. niger and Penicillium spp. were identified from the selected BARI-8, Nilima, Patharkuchi, Roma and Ratan varieties of tomato seeds. The highest (2.53%) mean incidence of the fungi F. moniliforme were recorded in tomato variety Roma, BARI-8, Nilima and Ratan while the lowest (0.13%) mean incidence of the fungi Penicillium was found in Ratan. The maximum percent of germination (64%) was recorded in both BARI-8 and Patharkuchi varieties, while the minimum (7%) germination in Nilima. The highest seedling vigor index (632.96) was encountered in BARI-8 and the lowest in Nilima. Trichoderma viride, T. harzianum and T. koningii were used as bio-control agents against major seed borne fungi. T. viride showed the significantly effective mycelial growth inhibition against F. moniliforme and C. lunata, while T. harzianum and T. koningii showed poor performance against both tested fungi. In case of botanical extracts, Lawsonia inermis exhibited the maximum (82.15% and 86.24%) inhibition of mycelium growth of F. moniliforme and C. lunata, respectively. Chemical fungicides, Bavistin (0.5 gm/l) inhibited 65% mycelial growth against F. moniliforme, while higher concentration of chemical fungicide gave 81% inhibition of C. lunata. The results suggested that, L. inermis phytoextract can possibly be exploited for the management of seed-borne pathogenic fungi of tomato in an environmental friendly way.Jahangirnagar University J. Biol. Sci. 6(2): 59-66, 2017 (December)

Management of seed-borne fungi in cowpea using leaf extracts and sodium bicarbonate

The study investigated the in-vitro antifungal activities of sodium bicarbonate (NaHCO3) and leaf extracts of Vernonia amydgalina (bitter leaf) and Azadirachta indica (neem) on fungal species isolated from two cowpea cultivars; IFE BROWN and Drum (a local cultivar). Concentrations of 1.95 mg/ml and 1.43 mg/ml were used for A. indica while 1.45 mg/ml and 1.15 mg/ml were used for V. amydgalina. Sodium bicarbonate was evaluated on all the isolates at 2.0 mg/ml and 3.0 mg/ml. The inhibitory effects of these antifungal agents were compared with benlate (a synthetic fungicide) on Potato Dextrose Agar. Benlate totally inhibited all the fungal isolates. Candida species isolated from the two cowpea cultivars were greatly inhibited by the antifungal agents while Trichoderma species isolated from IFE BROWN was the least inhibited. The inhibitory effects of NaHCO3 and A. indica on Candida spp. were not significantly different and values ranged from 74.5% to 84%. The two concentrations of A. indica had better inhibitory effect on Pythium spp. than NaHCO3. Vernonia amydgalina at 1.45 mg/ml inhibited A. niger and Candida spp. by 83.75% and 87.5% respectively while NaHCO3 at 2.0 mg/ml inhibited Rhizopus stolonifer isolated from Drum by 75%. The study concludes that the two plant extracts and sodium bicarbonate had broad spectrum activities on fungal species and are therefore recommended as alternatives to toxic and synthetic fungicides.Keywords: Cowpea, eco-friendly, fungicide, inhibition

Antifungal properties of Mimusops elengi seeds against paddy seed-borne fungi and selected pathogenic fungi

Antifungal properties of Mimusops elengi seeds against paddy seed-borne fungi and selected pathogenic fungi

Isolation and identification of seed borne fungi on dry bean and determination of their location on seed coats

This study was conducted at the Faculty of Agriculture, University of Omar AL-Mukhtar, during the growing seasons 2014-2015, aiming to justify many objectives including isolation and identification of seed-borne fungal pathogen on dry bean (Phaseolus vulgaris L.). The study also aimed to determine the location of pathogens on seed parts. The Seed samples were collected from the local market and underwent an isolation process after the surface sterilization of seeds to know the most important plant pathogens carried on beans seeds and determine their location and estimate their severity. Our results indicated that ten pathogenic fungi were isolated and identified as (Alternaria sp, Aspergillus niger, Aspergillus flavus, Penicillium sp ,Fusarium solani, Fusarium oxysporium ,Chaetumium sp,Rhizoctonia sp,Cladosporium sp, Botrytis cinearea). Results also emphasized the presence of fungi Rhizoctonia sp, Chaetumium sp in the seed coat, and Aspergillus sp ,Penicillium sp in embryio, While fungus Fusarium solani, ,Cladosporium sp, F. oxysporium , Alternaria sp ,Penicillium sp were noted in Cotyledons .

In vitro evaluation of selected fungicides and some plant extracts against seed-borne fungi of sesame (Sesamum indicum L.)

Abstract not availableBangladesh J. Sci. Res. 30(1&2): 91-95, December-2017