The Effect of Fungi Associated with Leaf Blight of Solanum Aethiopicum L

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u DOI: 10.4172/2157-7471.1000191 y o J ISSN: 2157-7471 Plant Pathology & Microbiology

Research Article Open Access

The Effect of Fungi Associated with Leaf Blight of Solanum aethiopicum L. in the Field on the Nutrient and Phytochemical Composition of the Leaves and Fruits of the Plant Ibiam OFA* and Nwigwe I Department of Applied Biology, Faculty of Biological Sciences, Ebonyi State University, Abakaliki, Nigeria

Abstract The leaves of Solanum aethiopicum L. in the field was investigated for possible isolation and identification of fungi associated with leaf-spot disease of the plant. The nutrients and phytochemical contents of the apparently healthy fruits and leaves and the infected leaves of Solanum aethiopicum L. were determined. Determined also is the effect of the disease on the nutrient and phyto-chemical content of the leaves. Results showed that Sclerotium rolfsii was isolated from the blighted leaves of Solanum aethiopicum L. The apparently healthy leaves had the highest amount of protein and carbohydrates, while the infected leaves had the least amount. Vitamin C and fibre contents were the highest in the apparently healthy fruit, but least in the infected leaves. The phosphate and phosphorus concentrations were the highest in the infected leaves than in healthy ones. The concentration of Na and Mn in infected leaves was higher than in apparently healthy fruit and leaves, whereas the Ca concentration in apparently healthy leaves was higher those in apparently healthy fruits and infected leaves. Nitrates and Nitrogen were in apparently healthy leaves and fruits than infected leaves.. The results of the nutrient content of apparently healthy leaves, fruits and the infected leaves have a significant difference (P<0.05). The levels of alkaloids and flavonoids were highest in the apparently healthy leaves than in apparently healthy fruits and infected leaves. The levels of Saponins were higher in the apparently healthy fruits, followed by those of apparently healthy leaves and least in the infected leaves. The infected leaves had the highest level of cytogenic glycosides, while the apparently healthy leaves and fruits had the same levels of the compound. The levels of these phytochemicals in the three samples of Solanum aethiopicum L. used in the study had no significant difference (P>0.05).

Keywords: Fungi; Leaf blight; Nutrient; Phytochemical-composition; results in scurvy with swelling of the joints and gums, loosening of Solanum aethiopicum L the teeth and haemorrhages of the skin and mucous membranes [8]. Calories in eggplants are very low; one cup of eggplant could give 20 Introduction calories, thereby making them ideal components of low fat diets [9]. Solanum aethiopicum L. is a delicacy in the Eastern part of Nigeria. The dietary fibers help lower blood sugar and blood cholesterol in the The immature fruits ofSolanum aethiopicum L. are used as cooked blood [10]. Moreover, since the fat content is less, they are excellent vegetables in stews and sometimes eaten raw. The leaves and shoots food for weight loss diets, as eggplants are nutrient dense food and help are used as cooked vegetables. Igbo people of South-Eastern Nigeria people feel full, thereby preventing over-eating, and Obese people love traditionally welcome visitors by offering the fruits. The leaves are eggplant nutrition and its low sodium diet is beneficial to hypertensive eaten as leafy vegetables and are actually more nutritious than the patients [11]. fruit. The fruits are usually harvested while still green, before the skin becomes thick. They are picked from the same plants that provide the The highly soluble minerals such as Calcium (Ca), Magnesium fruit or form special leafy cultivars. Fruits of bitter cultivars are used (Mg), Phosphorus (P), Iron (Fe) and Potassium (K), help in the as medicine in many African countries [1]. Medicinal applications maintenance of acid-base balance of the hydrogen ion concentration include the use of the roots and fruits as a carminative and sedative, of the body tissues, and also help complete the absorption of vitamins, and to treat coelic problems and high blood pressure, leaf juice as a proteins, fats and carbohydrates of food [12]. Ca and Fe furnish all sedative to treat uterine complaints, an alcoholic extract of leaves as a the cells and tissues of the body with the elements and nutritional sedative, anti-emetic and to treat tetanus after abortion, and crushed enzymes which they need; and the higher Calcium contents of Solanum and macerated fruits as an enema [2]. Some cultivars (Aculoatum aethiopicum L., suggests that they would be more advantageous to group) are occasionally used as a rootstock for tomato and eggplant [3]. Mueller et al. [4] reported that saponins contribute largely to the foam that rises to the top of the pot when you boil garden eggs, and should *Corresponding author: Ibiam OFA, Department of Applied Biology, Faculty of Biological Sciences, Ebonyi State University, Abakaliki, Nigeria, E-mail: be carefully skimmed off. Stemphylium disease ofSolanum aethiopicum [email protected] was caused by Stemphylium solani [5]. Received July 07, 2013; Accepted July 28, 2013; Published August 04, 2013

As a traditional food plant in Africa, this little known vegetable Citation: Ibiam OFA, Nwigwe I (2013) The Effect of Fungi Associated with Leaf has a potential to improve nutrition, boost food security, foster rural Blight of Solanum aethiopicum L. in the Field on the Nutrient and Phytochemical development and support sustainable land care [6]. S. aethiopicum L Composition of the Leaves and Fruits of the Plant. J Plant Pathol Microb 4: 191 doi:10.4172/2157-7471.1000191 is a wonderful source of potassium, manganese, copper, dietary fiber, folate, magnesium, niacin, vitamin B , B , C and K (in very small Copyright: © 2013 Ibiam OFA, et al. This is an open-access article distributed 1 2 under the terms of the Creative Commons Attribution License, which permits quantities) [7]. Ascorbic acid is essential for the healthy formation unrestricted use, distribution, and reproduction in any medium, provided the of the bones and teeth and a powerful antioxidant whose deficiency original author and source are credited.

J Plant Pathol Microb ISSN:2157-7471 JPPM, an open access journal Volume 4 • Isse 7 • 1000191 Citation: Ibiam OFA, Nwigwe I (2013) The Effect of Fungi Associated with Leaf Blight of Solanum aethiopicum L. in the Field on the Nutrient and Phytochemical Composition of the Leaves and Fruits of the Plant. J Plant Pathol Microb 4: 191 doi:10.4172/2157-7471.1000191

Page 2 of 5 the body in the functions associated with the minerals as Calcium is required for bone and teeth formation and in the proper functioning of the nervous system [4]. Potassium is required in muscles and nerve functions [13]. According to Olaiya and Adebisi [14], Phosphorus is important in the energy transfer of nucleic acids, its value ranging from 1.83 mg/100 g, and Iron is important in the formation hemoglobin of the blood. The vegetable Solanum aethipicum L is very low in carbohydrates, fats and proteins and therefore contribute very little to the energy values of a meal [15]. The fruits of Solanum aethipicum L. are known for possessing a diverse range of alkaloids, for example, tropane alkaloids [8] and these alkaloids can be desirable, toxic, or both, though they presumably evolved because they reduce the tendency of animals to eat the plants [6]. Some work has been done on the diseases of the crop and the proximate and phytochemical analysis of the crop. However, no work has been done on the effect of pathogen on the food value of the leaves. Hence, this work is aimed at isolation and identification of the fungi associated with the leaf blight disease in the field, determination of Figure 2: Mature leaves of Solanium aethiopicum showing symptoms of leaf phytochemical and nutrient composition of the fruits and the effect of blight. the fungi on the nutrient and phytochemical composition of the leaves. Nutrients A H F A H L I L Materials and Methods concentrations (%) concentrations (%) concentrations (%) mean ± SD mean ± SD mean ± SD The apparently healthy fruits, leaf and the infected leaf ofSolanum Moisture 47.898 ± 0.04 49.094 ± 0.01 63.44 ± 0.024 aethiopicum L. used in the study were obtained from Ugwulangwu in Ash 1.978 ± 0.04 0.930 ± 0.003 0.948 ± 0.001 Ohaozara L.G.A of Ebonyi State of Nigeria. The sample of the apparently Lipid 6.57 ± 0.02 1.39 ± 0.01 4.20 ± 0.01 healthy fruits and leaves were at their mature and greenish stage when CHO 8.866 ± 0.002 13.409 ± 0.001 6.846 ± 0.02 they were collected. The symptoms of on the infected leaves were at Protein 7.04 ± 0.02 8.78 ± 0.014 6.55 ± 0.022 their late stage when infected leaves were collected. Figure 1 represents Fibre 27.65 ± 0.1 26.40 ± 0.01 18.02 ± 0.03 a picture of apparently healthy farm of the plant showing apparently Vitamin C Concentrations Conc. (mg/100 g) Conc. (mg/100 g) healthy leaves and fruits and infected leaves. Figure 2 represent infected (mg/100 g) 235.51 ± 0.25 188.59 ± 0.01 leaves with the symptoms. 259.88 ± 0.18 (P<0.05) Fcal 9.74>Ftab 3.00 Methods of isolation A H F=apparently healthy fruits of Solanum aethiopicum The direct method of isolation of fungal pathogens was used. The A H L=apparently healthy leaves of Solanum aethiopicum I L=infected leaves of Solanum aethiopicum plant materials (fruits and leaves) were each cleaned to remove soils or Table 1: Proximate composition of the apparently healthy fruits, leaves, and the dirt’s by passing them over running water, washed with several changes infected leaves of Solanum aethiopicum. of distilled water, surface sterilized with 70% ethanol and cut into small pieces (4 mm2) with sterilized scapel. The work bench was also on their habit and spore characteristics using the method of Barnett and cleaned with 70% ethanol. The cut pieces of the fruits and leaves were Hunter [16]. The pure isolates were preserved and sub-cultured of every placed on a freshly prepared potato-Dextrose-Agar (PDA) media and fresh experiment carried out with them. incubated at room temperature 25 ± 2°C for 48hours, after which the fungal isolates were sub-cultured into pure culture and identified based Analyses of the food and mineral nutrients, vitamin C and anti-nutrients of the apparently healthy fruits and leaves, and infected leaves of Solanum aethiopicum The freshly harvested fruits and leaves ofSolanum aethiopicum termed apparently healthy and as well as the freshly harvested infected leaves analyzed in triplicate for carbohydrate, crude fibre, moisture, protein, lipid (fat); Vitamin C; mineral nutrients : anions- Nitrate,Phosphate, Phosphorus and Nitrogen; cations-Lead (Pb), Manganese (Mn), Magnesium (Mg), Zinc (Zn), Sodium (Na),Copper (Cu), Calcium (Ca) and Cadmium (Cd); and anti-nutrients- Flavonoid, Alkaloids, Saponins and Cyanogenic glycosides using standard method of AOAC [17]. Results Isolation and identification of the fungus Sclerotium rolfsii was implicated in the leaf blight of Solanum Figure 1: Mature plants of Solanium aethiopicum showing apparently healthy aethiopicum L. Figure 1 shows the pure culture of Sclerotium rolfsii. fruits and leaves and infected leaves. Table 1 shows the results of the proximate composition of the

J Plant Pathol Microb ISSN:2157-7471 JPPM, an open access journal Volume 4 • Issue 7 • 1000191 Citation: Ibiam OFA, Nwigwe I (2013) The Effect of Fungi Associated with Leaf Blight of Solanum aethiopicum L. in the Field on the Nutrient and Phytochemical Composition of the Leaves and Fruits of the Plant. J Plant Pathol Microb 4: 191 doi:10.4172/2157-7471.1000191

Page 3 of 5 apparently healthy fruits, and leaves, and the infected leaves of Solanum Phytochemicals A H F Conc. (mg/kg) A H L onc. (mg/kg) I L Conc. (mg/kg) aethiopicum L. means ± SD mean ± SD mean ± SD Alkaloids 2.12 ± 0.05 3.30 ± 0.01 2.96 ± 0.02 Investigation of the proximate composition Flavonoids 2.31 ± 0.01 4.18 ± 0.01 2.97 ± 0.015 Results in Table 1 showed that the apparently healthy leaves Saponin 4.33 ± 0.015 3.51 ± 0.01 0.20 ± 0.01 of Solanum aethiopicum L. had the highest amount of protein and Cytogenic 0.002 ± 0.00 0.002 ± 0.001 0.003 ± 0.00 carbohydrates, while the infected leaves were observed to have the glycosides least amount. The vitamin C and fibre contents were highest in the (P>0.05) Fcal 4.15Ftab 2.76 content was however, highest in the infected leaves studied than those in A H F=apparently healthy fruits of Solanum aethiopicum L. apparently healthy leaves and fruits which had equal levels of cytogenic A H L=apparently healthy leaves of Solanum aethiopicum L. glycosides. I L=Infected leaves of Solanum aethiopicum L. ND=Not determined Analysis of variance (ANOVA) carried out at 95% probability Table 2: The minerals (cations) and non–metallic (anions) content of the apparently revealed that there is no statistical significant difference (P>0.05) in healthy fruits leaves and infected leaves of S. aethiopicum. the phytochemical contents of the apparently healthy leaves and the infected leaves of Solanum aethiopicum L. used in the study. Non-metallic A H F Conc. (mg/kg) A H L onc. (mg/kg) I L Conc. (mg/kg) minerals means ± SD mean ± SD mean ± SD Discussion Phosphates 0.414 ± 0.002 0.413 ± 0.001 1.242 ± 0.003 Phosphorous 0.29 ± 0.11 0.188 ± 0.03 0.41 ± 0.003 Sclerotium rolfsii was isolated from the blighted leaves of Solanum Nitrates 61.80 ± 0.01 229.80 ± 0.03 132.39 ± 0.01 aethiopicum L., the reproductive structures and spores of the fungus in Nitrogen 0.11 ± 0.05 0.14 ± 0.10 0.107 ± 0.06 are shown in Figure 3. (p<0.05) Fcal 9.39>Ftab 4.76 Table 1, results of the proximate and vitamin C content of the A H F=apparently healthy fruits of Solanum aethiopicum L. apparently healthy fruits, leaves and the infected leaves of Solanum A H L=apparently healthy leaves of Solanum aethiopicum L. I L=Infected leaves of Solanum aethiopicum L. aethiopicum L. showed that the compositions of protein and Table 3: The non metalic minerals (anions) contents of the apparently healthy carbohydrates were highest in the apparently healthy leaves, while the fruits, apparently healthy leaves and infected leaves of Solanum aethiopicum. vitamin C, fibre, lipids and ash contents were highest in the apparently

Page 4 of 5 healthy fruits studied. The moisture content was however, highest in desirable, toxic or both and that they reduce the tendency of pathogens the infected leaves examined. Results also show that the infected leaves to invade the plants. Muller et al. [4], stated that saponins exhibit potent had the least amount of vitamin C, fibre, protein and carbohydrates antifungal activities. The relative high levels of saponins in apparently (Table 1). Analysis of variance (ANOVA) carried out at 95% probability healthy fruits and leaves of Solanum aethiopicum L in this study agrees showed that the proximate and vitamin C content of the apparently with Mueller et al. [4]. This is due to the fact that saponins had 4.33 healthy fruits, leaves, and the infected leaves of Solanum aethiopicum ± 0.01% and 0.20 ± 0.01% in apparently healthy fruits, leaves and the L used in the study were significantly different (p<0.05). According to infected leaves of the egg plant respectively in the present findings. Gropper et al. [15], the shelf life of the leaves of Solanum aethiopicum The levels of cytogenic glycosides were highest in the infected leaves L. is very short because the leaf of Solanum aethiopicum L. is very short when compared to the apparently healthy fruits and leaves. Analysis because the leaf has high moisture content which facilitates microbial of variance (ANOVA) carried out at 95% probability however, showed action resulting into spoilage. In the present investigation the moisture that the results have no significant difference (p>0.05). contents of both the infected and the apparently healthy leaves were Although the anti-nutrients observed in this study largely contribute relatively higher than in apparently healthy fruits with the infected to plants” resistance to fungal attack, Rizza et al. [22], Olmstead and leaves having the highest amount of moisture. This shows that the high Palmer [23] and Martin et al. [24] had reported that massive doses of moisture content of the leaves must have facilitated the fungal activities saponins in the fruits and leaves of Solanum aethiopicum L. could lead to on the leaf, leading to the degradation and dissolution of the tissue several degrees of health hazards ranging from leaky gut to haemolysis by the fungi and the resultant increase in the moisture content of the of red blood cells, it is recommended that controlled eating of the fruits infected leaves. The utilization of the vitamin C, fibre, protein and the and leaves of Solanum aethiopicum L. should be done. carbohydrates content of the infected leaf by the fungal pathogen during their degradative activities on the infected leaves must be responsible Conclusion for their relative decrease in the infected leaves. When compared to the apparently healthy fruits and leaves, the high ash content 1.978% and From the studies carried out in this research, there is a clear evidence the lipid content (6.575) of the apparently healthy fruits suggest that that Sclerotium rolfsii, affect Solanum aethiopicum L. in the field and apparently healthy fruits of Solanum aethiopicum L. are rich in organic the activities of this fungi is facilitated by high moisture content of the matter. plant, further studies may still be carried out on the plant in relation to its fungal association on the nutrient composition and the resultant Since the vitamin C, fibre carbohydrates and protein contents effects for more discovery. of the infected leaves have been reduced by the fungal pathogens, it means that by continued consumption of such leaves by man be will References not derived enough vitamin C from them. Szeto et al. 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This corroborates the claims of Brunning [19] that the micro and macro nutrients in plants are used as food by fungi and that is why they can 8. Szeto YT, Tomlinson B, Benzie IF (2002) Total antioxidant and ascorbic acid content of fresh fruits and vegetables: implications for dietary planning and food easily attack the plants. Marzluf [20] and Hynes [21] also stated that preservation. Br J Nutr 87: 55-59. fungi use a diverse range of organic substrates for growth including 9. Daunay MC, Maggioni L, Lipman E (2003) European Cooperative Programme simple compounds as nitrates, ammonia, ethanol etc. for Crops Genetic Resources Network, solananceae Genetic Resources in Europe. 2141. Since the present study reveals that fungal activities in the leaves can lead to a decrease in the mineral contents of the apparently healthy 10. 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J Plant Pathol Microb ISSN:2157-7471 JPPM, an open access journal Volume 4 • Issue 7 • 1000191