ArticlePDF Available

Isolation and Identification of Fungi Associated With Tomato (Lycopersicon Esculentum M.) ROT

Authors:
  • Kogi State University, Anyigba, Kogi State

Abstract

Tomato (Lycopersicon esculentum) is the most popular vegetable worldwide. They have high spoilage rate because of their high moisture content. Many pathogenic fungi are the subject of intense study because they cause disease symptoms that have negative effect on the yield and quality of tomato fruits; they produce mycotoxins that are detrimental to human health. Isolation and identification of fungal organisms causing rot of tomato purchased from Anyigba main market was carried out. Sabouraud Dextrose Agar was used and four fungal species were isolated; Aspergillus spp, Penicillium spp, Rhizopus spp and Fusarium spp. The most frequent being Aspergillus spp (38.89%) and the lowest was Fusarium spp (5.56%). The pathogenicity test carried out implicated these organisms in the spoilage of healthy tomato fruits. Proper handling and adequate storage facilities must therefore be employed to prolong the shelf life of tomato fruits.
Sumerianz Journal of Agriculture and Veterinary, 2020, Vol. 3, No. 5, pp. 54-56
ISSN(e): 2617-3077, ISSN(p): 2617-3131
Website: https://www.sumerianz.com
© Sumerianz Publication
CC BY: Creative Commons Attribution License 4.0
Original Article Open Access
*Corresponding Author
54 54
Isolation and Identification of Fungi Associated With Tomato (Lycopersicon
Esculentum M.) ROT
Yusuf Lamidi *
Department of Microbiology Kogi State University, Anyigba, Kogi State, Nigeria
Agieni G. A.
Department of Microbiology Kogi State University, Anyigba, Kogi State, Nigeria
Olorunmowaju Abiodun Israel
Department of Microbiology Kogi State University, Anyigba, Kogi State, Nigeria
Abstract
Tomato (Lycopersicon esculentum) is the most popular vegetable worldwide. They have high spoilage rate because
of their high moisture content. Many pathogenic fungi are the subject of intense study because they cause disease
symptoms that have negative effect on the yield and quality of tomato fruits; they produce mycotoxins that are
detrimental to human health. Isolation and identification of fungal organisms causing rot of tomato purchased from
Anyigba main market was carried out. Sabouraud Dextrose Agar was used and four fungal species were isolated;
Aspergillus spp, Penicillium spp, Rhizopus spp and Fusarium spp. The most frequent being Aspergillus spp
(38.89%) and the lowest was Fusarium spp (5.56%). The pathogenicity test carried out implicated these organisms
in the spoilage of healthy tomato fruits. Proper handling and adequate storage facilities must therefore be employed
to prolong the shelf life of tomato fruits.
Keywords: Tomato; Fungi; Isolation; Identification; Rot; Pathogenicity test.
1. Introduction
Tomato (Lycopersicon esculentum M.) belongs to the family Solanaceae is one of the most widely grown and
extensively consumed vegetable in the world. In the Nigerian Savanna, fresh tomato is the most valuable vegetable
crop. It accounts for about 18% of the average daily consumption of vegetables in Nigeria. Tomatoes may be pear-
shaped, elongated, flattened and heart shaped. They are edible, fleshy and reddish when ripe and vary in their acid
composition, with white and yellow ones being less acidic. Tomatoes can be used as savoury or flavouring in soups
and cooked foods or can be eaten as fruits. It is used in many dishes, salads, sauces and drinks and can also be dried
and ground into pancakes [1]. Tomato fruits are mostly harvested and transported in manners that expose them to
microbial infections; they are usually harvested and transported with locally made baskets which are prone to fungal
contaminants. They are usually displayed on benches and in baskets for prospective customers in the open market
until sold, thereby exposing them to further microbial infections beside those associated with its surface and those
from adjacent infected fruits [2]. Fungi are the most important and prevalent pathogens, infecting a wide range of
fruits and causing destructive and economically important losses of the fruits during storage, transportation and
marketing [3]. These study aims at identifying fungal causing tomato rot from Anyigba Main Market, Kogi State,
Nigeria.
2. Materials and Methods
Fresh tomato samples were purchased from Anyigba main market in Kogi State, Nigeria. They were rinsed with
sterile distilled water and transported to the Microbiology laboratory, Kogi State University in sterile polythene bags
for fungal isolation. The samples were left for seven (7) days for spoilage to occur. These spoilt tomatoes were then
used for the study. One gram (1 g) of each of the spoilt tomatoes was carefully cut with the aid of a sterile scalpel,
ten-fold serial dilutions of the sample were thereafter carried out in serially marked test tubes for a serial dilution
process and then removed and an appropriate dilution factor was obtained from the isolation of distinct colonies and
enriched in sterile Sabouraud dextrose agar media for seventy two (72) hours. The 10-3 diluent was used for
incubation. Following sample preparation, an aliquot (1ml) from the tube with the highest dilution factor (10-3) was
inoculated onto the already prepared SDA media with 1ml of chloramphenicol to inhibit bacteria growth using the
spread plate method. This procedure was repeated for the subsequent plates, and was left to gel prior to incubation in
an inverted position in the incubator at 25oc ±2 for 72 hours. The colonies that developed were then counted and
enumerated in colony forming unit per ml (cfu/ml). They were later subculture before identification and
characterization. Pathogenicity test was done using the procedures of Baiyewu, et al. [2] with ten (10) healthy
tomatoes inoculated and another ten bored that serves as control. The rot diameters were measured after the seventh
day of inoculation.
Sumerianz Journal of Agriculture and Veterinary
55
3. Results and Discussion
In this investigation, the fungi Aspergillus spp, Penicillium spp, Rhizopus spp and Fusarium spp were isolated.
The precise identification of these pathogens is central of an appropriate disease management strategy. Table 1
shows that isolated Aspergillus spp is one of the major fungi responsible for the production of volatile compounds in
spoilt tomato. Baker [4], reported that they are pathogenic on tomato fruits. Akinmusire [5] reported that Rhizopus
spp were associated with tomato spoilage. Wogu and Ofuase [6] isolated Aspergillus, Penicillium, Fusarium from
spoilt tomato fruits.
Extending the shelf life of tomato fruits by controlling its ripening when it is to be transported over a long
distance can be employed. Appropriate temperature and relative humidity should be employed in tomato fruit
storage. Earlier workers have suggested 30-35oc and 50-80% relative humidity for its storage. Mechanically injured
and fungal infected fruits should not be package with healthy fruits, so as to prevent mass deterioration of tomato
fruits. Hayatu [7], reported that the high number of fungal colonies isolated on tomato could be due to physical
damage, and harvesting puncture, which could occur during harvesting and poor handling, which serve as portal of
entry for microbes. The result from Table 2 shows that all the isolates grow best aerobically as there were reductions
in their occurrence at anaerobic condition. However, Fusarium spp showed no growth anaerobically; this may be due
to the fact that Fusarium spp were obligate anaerobes. This shows that the oxygen concentration in a particular
environment also contribute to the spoilage organisms to be present in the tomato fruits.
The results of the pathogenicity tests show that these fungal isolates were capable of causing disease if the right
conditions were given. An observation worthy of note was given to a tomato species that has resistibility to fungal
spoilage; the Roma tomato. Roma tomato was able to maintain a healthy condition even when other species of the
fruit has deteriorated due to fungal spoilage (Plate 1). Morphological and microscopic characteristics were compared
with initial cultures after re-isolation and were found to be the same. The control (with bored whole and no isolate
inoculated) shows no symptoms of rot at the third day of examination. The ability of the fungal isolate to cause
disease in healthy tomato fruits was due to the fact that the pathogens are able to utilize the nutrients of the fruits as a
substrate for growth and development [8]. This was shown in Table 3 where the rot diameter of each fungi isolate
after 7 days was carefully measured.
Plate-1. Tomato fruits after the third day of fungal activity
Table-1. Occurrence Rate of Fungal Isolates
Fungal Isolates
Number of Occurrence
Rate of Occurrence (%)
Aspergillus spp.
28
38.89
Penicillium spp.
24
33.33
Rhizopus spp.
16
22.22
Fusarium spp.
4
5.56
TOTAL
72
100
Table-2. Occurrence Rate of Fungal Isolates by Spoilage Pattern
AEROBIC
ANAEROBIC
Isolates
Frequency (%)
Isolate
Frequency (%)
Aspergillus spp.
41.67
8
33.33
Penicillium spp.
27.08
11
45.83
Rhizopus spp.
22.92
5
20.83
Fusarium spp.
8.33
0
0
TOTAL
100
24
99.99
Table-3. The Rot Diameter of Fungal Isolates
Sumerianz Journal of Agriculture and Veterinary
56
Isolate
Rot diameter (mm)
Aspergillus spp
20.0
Penicillium spp
8.2
Rhizopus spp
14.6
Fusarium spp
12.5
4. Conclusion
Many studies have been carried out with respect to occurrence, casual organisms, severity, losses and
pathogenicity. The present study implicated four fungal pathogens (Aspergillus, Penicillium, Rhizopus and
Fusarium) in the spoilage of tomato fruit. Tomato fruits were prone to fungal infection. This study also shows the
high occurrence of Aspergillus spp in Anyigba metropolis compare to other fungal contaminants. Control measures
must be employed by vegetative growers, marketers and consumers at the time of harvesting, transportation,
handling, storage and processing of tomato fruits to reduce these contaminants.
5. Recommendation
It is recommended that tomato fruits production should be handled with extreme care. Only recommended
chemicals are used at recommended dosage for its production and avoid the use of water flooded with untreated
sewage for irrigation. The resistant tomato species; “Roma tomato” )Plate 1) should be given more attention to detect
the genetic trait that lead to its resistibility, its productivity should also be on the increase. Individuals who prefer to
consume spoilt tomato fruits because it is very cheap should also desist as this may serve as a cheap source of
diseases too. Washing the tomato with clean water before consumption will also reduce the bacterial load.
References
[1] Onuorah, S. and Orji, M. U., 2015. "Fungi associated with the spoilage of post-harvest tomato fruits sold in
major markets in Awka, Nigeria." Universal Journal of Microbiology Research, vol. 3, pp. 11-16.
[2] Baiyewu, R. A., Amusa, N. A., Ayoola, O. A., and Babalola, O. O., 2007. "Survey of the post-harvest
disease and aflatoxin contamination of marketed pawpaw fruit (carica papaya l.) in South Western Nigeria."
Africa Journal of Agricultural Sciences, vol. 2, pp. 178-181.
[3] Sommer, N. F., Fortingae, R. J., and Edwards, D. C., 1992. "Postharvest diseases of selected commodities
(Kader A.A. Ed)." University of California Division of Natural Resources Publication, vol. 31, pp. 117-
160.
[4] Baker, S., 2006. "Aspergillus niger genomics: Past, present and into the future." Medical Mycology, vol. 44,
pp. S17-21.
[5] Akinmusire, O. O., 2006. "Fungi species associated with the spoilage of some edible fruits in maiduguri,
North Eastern Nigeria." Advances in Environmental Biology, vol. 5, pp. 157-161.
[6] Wogu, M. D. and Ofuase, O., 2014. "Microorganisms responsible for the spoilage of tomato fruits,
Lycopersicum esculentum, sold in markets in Benin City, Southern Nigeria." Scholar’s Academic Journal
of Bioscience, vol. 2, pp. 459-466.
[7] Hayatu, M., 2000. Post-harvest physiological studies of some selected members of family Solanaceae. M.
Sc Thesis (unpublished). Dept. of Biological Sciences, Bayero University, Kano., p. 25.
[8] Kator, L., Akomaye, M. U., and Okoro, J. K., 2015. "Efficacy of some botanicals in the control of fungi
causing postharvest rot of yam in katube market, Obudu, Nigeria." IOSR Journal of Pharmacy and
Biological Sciences, vol. 10, pp. 33-41.
... Tomato (Lycopersicon esculentum) belongs to the family Solanaceae which is regarded as one of the most important, cultivated and consumed vegetable in the world (Lamidi et al., 2020;Maurya et al., 2022). Monte et al. (2013) reported that about 146 million tons of fresh tomato fruits are produced annually throughout the world. ...
... It also contains high amount of β-carotene, vitamin C and lycopene, a carotenoid with antioxidant properties (Britt & Kristin, 2011;Dandago et al., 2018;Rani & Khetarpaul, 2009). In Nigeria, tomato fruits consumption accounts for about 18% of the daily consumption of vegetables (Lamidi et al., 2020). Nigeria is the second largest producer of tomatoes in Africa and 13 th largest in the world (FAOSTAT, 2014). ...
Article
Full-text available
Purpose: Fungal infections have become the most common problem to cause postharvest loss in tomato enterprise across Nigeria. Morphology-based identification of fungal species usually provides the inconclusive results with several species remain unidentified. Molecular identification method was used to supplement morphology-based techniques to identify the fungal species. Research Method: A Deoxyribonucleic Acid (DNA) through 5.8S-ITS (Internal Transcribed Spacer) region of the ribosomal DNA (rDNA) was used to identify 180 infested tomato specimens. The samples were collected from farm, retail and wholesale points in Kwanar Gafan located at Kura LGA of Kano State. Findings: Eight haplotypes have been detected from the total fungal specimens examined, A 65.6% of fungal specimens from wholesales and farms constituted haplotype-1 and identified as Pichia kudriavzevii (with 99.54% similarity) as BLAST in National Centre for Biotechnology Information (NCBI) database. The remaining seven haplotypes were exclusively found in the retailing points and largely constitutes Aspergillus spp., Mucor fragilis, Russula atroglauca, Ganoderma sp., Alternaria spp., Exserohilum rostratum, Colletotrichum boninense, Naganishia sp. and Cladosporium spp. Research limitations: Further research on molecular identification from other parts of kano is required for better understanding the fungi associated with postharvest loss in the state. Originality/Value: Pichia kudriavzevii is a single and only dominant fungal species that infest tomatoes in both farms and wholesale points (65.6%). However, 34.4% of the diverse fungal species have been found in retailing points which is related to the rapid infestation of tomatoes.
... The fruits were then placed in individual sterile polyethene zip-lock bags to retain humidity and incubated for 7 days at ambient temperature to simulate shelf-life storage conditions. The relative humidity and temperature were maintained between 50 and 60% and 25-27 • C for the incubation period, respectively, as previously suggested for appropriate storage of tomato fruits (Lamidi et al., 2020). The percentage spoilage incidence was determined using an adapted formula by Kabiru and Yusuf (2024) as follows: ...
Article
Full-text available
Rhizopus rot is considered one of the most common diseases influencing global production and yield of horticulture commodities. However, the factors contributing to this pattern of prevalence are uncertain. Here, we focused on R. microsporus, which is known to rely on its endosymbiotic bacterium, Mycetohabitans, to produce toxins that interfere with plant development and inhibit the growth of other fungi. We assessed the impact of the symbiotic R. microsporus harboring its endosymbiont as well as the fungus cured of it on: (1) the magnitude of spoilage in tomato fruits, as evaluated by Koch's postulate for pathogenicity, (2) the shifts in native communities of endophytic fungi inhabiting these fruits, as examined by ITS rRNA gene metabarcoding and (3) secondary metabolites generated by these communities, as analyzed using multi-analyte LC-MS/MS. The pathogenicity test showed that the symbiotic endobacterium-containing R. microsporus W2-50 was able to cause tomato fruit spoilage. This was accompanied by decreased relative abundance of Alternaria spp. and an increase in the relative abundance of Penicillium spp. that may have facilitated the observed spoilage. In conclusion, symbiotic W2-50 appeared to facilitate fruit spoilage, possibly through successful colonization or toxin production by its endosymbiont.
... Pectinolytic enzymes are of significance in the current biotechnological era with their embracing applications in food industries, alcoholic beverages and tea fermentation (Sharma et al., 2011). In this study, fungi Aspergillus niger, Penicillium nigricans, Fusarium oxysporium, Rhizopus stolonifer and Trichoderma harzanium were isolated from spoilt tomato and this is comparable to the findings of Yusuf et al., (2020), who identified the same organisms from his study. He stated that Aspergillus spp is one of the major fungi responsible for the production of volatile compound in spoilt tomato. ...
Article
Full-text available
Microbes are well known source for the production of extracellular enzymes and industrial important secondary metabolites. Since fruits contain pectin, hence any microorganism that will involve in their spoilage must naturally possess cell wall destroying ability. This study was aimed at isolation and characterization of pectinase producing fungi from Tomato fruits. Tomato fruits were collected from Bodija. Market, Ibadan, Nigeria. Spoilage fungi were isolated and characterized with standard techniques. Six (6) fungi were isolated from the fruits: Aspergillus niger, Penicillium nigricans, Rhizopus stolonifer, Fusarium oxysporium and Trichoderma harzanium. The fungi were screened for the pectinolytic enzyme production on solid media. Among the isolates, Aspergillus niger, Penicillium nigricans, Rhizopus stolonifer and Fusarium oxysporium were selected for pectinase production using solid state fermentation (SSF) with Orange peel. Crude enzyme production was optimized with pH, temperature, substrate concentrations and incubation period. All the isolates produced maximally at pH 7, 1.5 substrate concentration , 50 0 C and 72Hr incubation except Penicillium nigricans at pH(5) and temperature of 40 o C. These organisms can further be studied for their enzymes to be purified and characterized.
... Likewise, species of Aspergillus, Fusarium, Rhizopus, Penicillium and Candida were associated with spoilage of pineapple sold in Awka Market [13]. The presence of Fusarium sp., Rhizopus stolonifer and Mucor Sp. on tomato confirmed the studies of Oluwakemi et al. [14] and Lamidi [15] who reported that Fusarium sp, and Rhizopus stolonifer are responsible for the soft rot of tomato. ...
Article
Full-text available
Wilt disease of tomato is caused by Fusarium oxysporum f. sp. lycopersici and it is an important disease which causes significant yield reduction in the crop throughout the world. A study was undertaken to isolate, identify and test the pathogenicity of F. oxysporum f. sp. Lycopersici on tomato; and to evaluate the bioactivity of Azadirachta indica leaf, Piper guineense seed and Zingiber officinale rhizome extracts as well as the synthetic fungicide, mancozeb at different concentrations and combinations for the management of F. oxysporum f. sp. lycopersici in vitro. Results revealed that the percentage frequency of the fungus isolated and identified was more on the roots (35.56 %) than the stems (26.67 %), fruits (20.00 %) and leaves (17.77 %). Results of the pathogenicity test showed more virulence in the roots than in other parts of the tomato plant. Extracts of the three plants and mancozeb proved effective in controlling the mycelial growth of the fungus either alone or when combined. Mancozeb consistently gave 100 % growth inhibition irrespective of the concentration used. Among the plant extracts applied alone at 40 g/L, Z. officinale (66.69 %) was the most effective followed by P. guineense (53.52 %) while A. indica was the least (36.99 %). The mycelial growth inhibition increased from 40 g/L to 120 g/L irrespective of the combination of the treatments used. A combination of mancozeb with any plant extract was more effective than a combination of the plant extracts. It is therefore, recommended that the plant extracts be applied either alone or in combination with other plant extracts or the fungicide to control F. oxysporum f. sp. lycopersici, increase tomato yield and reduce postharvest rots associated with the pathogen. Keywords: Fusarium oxysporum f. sp. lycopersici; Fusarium wilt; Inhibition; Pathogenicity, Plant extract, Mancozeb; Tomato
Article
Full-text available
Tomato contains large amount of water which makes it more susceptible to spoilage by fungi. These fungi that spoil tomatoes produce mycotoxins that are detrimental to human health. This study was therefore carried out to isolate, characterize and identify the fungi associated with the spoilage of tomato fruits sold in Okpuno, Amaudo, Eke- Awka, Nodu and Amaikwo Markets in Awka, Nigeria. The average fungal counts ranged between 1.3 x 103 and 2.0 x 103 cfu/ml, while the fungal isolates were Aspergillus niger, Rhizopus stolonifer, Fusarium oxysporum, Saccharomyces cerevisiae, Alternaria alternata, Penicillium digitatum and Geotrichum candidum. The percentage occurrence of the isolates in the fruits from Eke Awka was the highest (32.73%) while that of the fruits from Nodu market was the least (12.73%). Aspergillus niger had the highest percentage occurrence (47.27%) in the fruits studied, with Saccharomyces cerevisiae and Geotrichum candidum having the lowest percentage occurrence (3.64%). Pathogenicity test result showed that Aspergillus niger also had the highest decay diameter of 30mm in the healthy tomato fruits while Geotrichum candidum had the lowest decay diameter. Proper handling and adequate storage facilities must therefore be employed to prolong the shelf life of tomato fruits.
Article
Full-text available
Survey and collection of the marketed pawpaw fruit with rot symptoms were conducted in the South Western Nigeria in 2000 and 2001 respectively. Pawpaw fruits showing rot symptoms that are displayed for sale in three different market places in three major cities in south western Nigeria namely, Ibadan, Abeokuta and Akure were collected and examined for the presence f the inducing pathogens and for aflatoxin contamination. The most commonly fungi found in rotten pawpaw fruits were: Rhizopus nigricans, Curvularia lunata, Aspergillus flavus, Aspergillus niger, Fusarium moniliforme, Colletotrichum capsici and Trichoderma viride. Rhizopus nigricans, F. moniliforme A. flavus and A. niger had the highest rate of occurrence among the isolated fungi while C. lunata was the least encountered. Pathogenicity tests revealed that of all the isolated fungi, R. nigricans, C. lunata and F. moniliforme were highly pathogenic with the first two leading to rapid disintegration of treated fruits in 3-5 days. A. niger was moderately pathogenic, while A. flavus T. viride caused the least amount of rot on pawpaw fruits. Aflatoxins were detected from infected pawpaw fruits, both before and after autoclaving fruit for 15 min at 121oC.
Article
Full-text available
Aspergillus niger is a filamentous ascomycete fungus that is ubiquitous in the environment and has been implicated in opportunistic infections of humans. In addition to its role as an opportunistic human pathogen, A. niger is economically important as a fermentation organism used for the production of citric acid. Industrial citric acid production by A. niger represents one of the most efficient, highest yield bioprocesses in use currently by industry. The genome size of A. niger is estimated to be between 35.5 and 38.5 megabases (Mb) divided among eight chromosomes/linkage groups that vary in size from 3.5-6.6 Mb. Currently, there are three independent A. niger genome projects, an indication of the economic importance of this organism. The rich amount of data resulting from these multiple A. niger genome sequences will be used for basic and applied research programs applicable to fermentation process development, morphology and pathogenicity.
Article
The spoilage of Pawpaw (Carica papaya), Orange (Citrus sinensis), Pineapple (Ananas comosus) and Tomato (Lycopersicon esculentum) from three selected markets in Maiduguri, Borno state, northeastern Nigeria were investigated. The fruits (Pawpaw, Orange, Pineapple and Tomato) showing spoilage signs were examined for the presence of fungal pathogens inducing spoilage. Two fungal species Aspergillus flavus. and Rhizopus stolonifer; were found associated with deteriorating Carica papaya. Aspergillus niger and Candida tropicalis sp. were associated with Citrus sinensis, the mycoflora found associated with Ananas comosus were Phytophthora sp; Aspergillus flavus and Candida tropicalis, while Fusarium oxysporum, Rhizopus stolonifer and Mucor sp. were found associated with the spoilage of Lycopersicon esculentum. Aspergillus species had the highest rate of occurrence among the isolated fungi, followed by Rhizopus and Candida species while Fusarium sp, Phytopthora sp, and Mucor sp. were the least encountered. Pathogencity tests revealed that all the isolated fungi were pathogenic to the different fruits.
University of California Division of Natural Resources Publication
  • N F Sommer
  • R J Fortingae
  • D C Edwards
Sommer, N. F., Fortingae, R. J., and Edwards, D. C., 1992. "Postharvest diseases of selected commodities (Kader A.A. Ed)." University of California Division of Natural Resources Publication, vol. 31, pp. 117-160.
Microorganisms responsible for the spoilage of tomato fruits, Lycopersicum esculentum, sold in markets in Benin City, Southern Nigeria
  • M D Wogu
  • O Ofuase
Wogu, M. D. and Ofuase, O., 2014. "Microorganisms responsible for the spoilage of tomato fruits, Lycopersicum esculentum, sold in markets in Benin City, Southern Nigeria." Scholar's Academic Journal of Bioscience, vol. 2, pp. 459-466.
Post-harvest physiological studies of some selected members of family Solanaceae
  • M Hayatu
Hayatu, M., 2000. Post-harvest physiological studies of some selected members of family Solanaceae. M. Sc Thesis (unpublished). Dept. of Biological Sciences, Bayero University, Kano., p. 25.