ANTIFUNGAL ACTIVITY OF SOME SELECTED PLANT

EXTRACT AGAINST POST HARVEST LOSS OF SOYBEAN

(Glycine max L.) Merr. CAUSED BY Fusarium oxyporum AND

Drechslera glycines

MOSES TEMITOPE ADEGOKE

MATRIC. NO. 181493

INTRODUCTION

Soybean (Glycine max (L.) Merrill), is a major leguminous crop

cultivated worldwide including Nigeria.

Soy products are relatively inexpensive sources of high quality

proteins, oil content which is in the form of food, feed and industrial uses

(Sharma et al., 2014).

Soybean seeds are infected with various seed-borne microorganisms,

including fungi, bacteria and viruses (Krishnamurthy and Shashikala

2006).

INTRODUCTION CONT’D

The associated soybean seed-borne fungi reported are Aspergillus flavus,

A. niger, Cercospora kikuchi, Macrophomina phaseolina, Fusarium

oxysporum Drechslera glycines etc (Krishnamurthy et al., 2008, Impullitti an

d Malvick, 2013).

In recent years, antimicrobial properties of plant extracts have been

reported with increasing frequency from different parts of the world (Cowan,

1999).

Different plant tissues, such as roots, leaves, seeds and flowers possess

inhibitory properties against bacteria, fungi and insects (Davicino et al.,

2007).

PROBLEM STATEMENT

The constant use of synthetic fungicide in crop production has lead to the

high risk in the level of toxic residues whch affects health and environment

concerns.

JUSTIFICATION

The use of biologically based compounds from plant extracts is an

alternative to fungicides in the control of phytopathogenic fungi with plant

products which are cost effective and ecofriendly has been successful in

several instances.

To develop a sustainable integrated control strategy against the pathogenic

fungi of soybean; treatment of seeds with botanicals becomes a necessity.

AIM

To evaluate the antifungal activity of some selected plant extracts against

postharvest loss of Soybean caused by Fusarium oxysporum and Drechslera

glycines (Glycine max L.).

OBJECIVES

To isolate fungi associated with soybean seeds.

To determine the incidence and percentage occurrence of fungi.

To assess pathogenicity potential of fungi associated with Soybean seeds.

To assess the antifungal activities of plant extracts at varied concentrations

against Fusarium oxysporum and Drechslera glycines of soybean.

Plant Species Native name Family Part used

Acalypha fimbriata Jiwene Euphorbiaceae Whole Plant

Citrus sinensis Osan mumu Rutaceae Leaves

Datura metel Apikan Solanaceae Leaves

Lawsonia inermis Laali Lythraceae Leaves

MATERIALS AND METHODS

Source of plant collection:

Table 1. Botanical description of selected plants.

MATERIALS AND METHODS CONT’D

Source of materials

Seed samples were collected from 3 markets: Bodija: LAT: 7o 26'6.4531"N),

LON: (3o54'51.5254"E); Bode: LAT: (7021'43.0488"N), LON: 3o53'29.4043"E),

Agbeni-Ogunpa: LAT: (7o22'48.3906"N), LON: (3053'25.0029"E) and

NACGRAB (TGX 1448-ZE) (LAT: o22'53.3262"N), LON: 3o50'23.4072"E).

Experimental Design

Completely Randomized Design (CRD).

Extraction procedure:

Aqueous extraction with 3 concentrations: 5g/ml, 10g/ml and 15g/ml and were

filtered by four fold muslin cloth (Wokocha and Okereke, 2005).

MATERIALS AND METHODS CONT’D

Detection and Identification of associated fungi:.

Fungi isolated were detected by agar plate method (ISTA, 1924) and each

fungus was identified.

Detection of fungi occurrence

Type and frequency of occurrence of identified fungal species was recorded.

Pathogenicity potential of fungi

The seed samples were inoculated with 5mm of each fungus and plated using

blotter method. Plates were incubated at 27°c for 7days. (Bankole S.1996 and

Steven, et al., 2005).

Antifungal investigation by poison food method

2ml of each extract was added to 15ml potato dextrose agar (PDA) media which

was inoculated with 5mm agar disc and incubated at 27°c (Onuh et al., 2005).

Sample A: Healthy Seed Sample B: Diseased Seed

Plate 1: Showing Soybean seed samples

MATERIALS AND METHODS CONT’D

MATERIALS AND METHODS CONT’D

Treatments: Each treatment were replicated three times.

1. T1 (A. fimbriata)

2. T2 (C. sinensis)

• T3 (D. metel)

1. T4 ( L. inermis)

2. T5 ( Standard drug, Control 1)

3. T6 ( Control 2).

Statistical Analysis

Data obtained from mycelial growth inhibition were subjected to analysis

of variance (ANOVA) using SAS 2010 version 16.

1. The Duncan Multiple Range Test (DMRT) was used to ascertain the

significance between the different treatment means at 5% level of probability.

Means followed the same letter (s) in the same column are not significant different at P= 0.05

Table 2: Incidence of species of fungi associated with soybean grains

Fungi Isolate Bodija Market

Bode Market

Agbeni-OgunpaMarket

NACGRAB

A. flavus 3a 2b 1c 0c

A. fumigates 2b 2b 1c 0c

A. niger 3a 3a 3a 0c

A. tamarii 1c 0c 1c 0c

F. oxysporum 3a 0c 2b 2b

D. glycines 0d 2b 1c 3a

Penicillium sp. 1c 2b 1c 2b

Trichoderma sp. 1c 0c 0d 0c

Total Incidence 14 11 10 7

% Incidence 33.33 26.19 23.81 16.67

RESULTS

Fungi Isolate % G % R Shoot Length (cm)

Root Length (cm)

Seedling Vigour Index

A. flavus 60.00ab 26.32bc 3.80ab 3.50b 506.67cd

A.fumigatus 76.67ab 3.70d 2.80b 4.33b 557.00cd

A. niger 66.67ab 16.80cd 2.60b 4.10b 456.00cde

A. tamarii 76.67ab 3.11d 3.80ab 8.97a 977.70a

F. Oxysporum 36.67d 53.17a 2.30b 3.67b 226.70c

D. glycines 46.67cd 41.60ab 2.33b 3.13b 254.7de

Penicillium sp. 73.33ab 7.41cd 4.50a 7.33a 862.3ab

Trichoderma sp. 70.00ab 12.04cd 3.30ab 3.43b 471.30cde

Control 80a 0.00d 3.03ab 4.10b 580.0bc

RESULTS CONT’DTable 3: Effect of seed-borne fungi on the germination, reduction,

seedling vigour and growth characters of soybean seed.

Means followed the same letter (s) in the same column are not significant different at P= 0.05

A. Effect of F. oxysporum B. Effect of D. glycines

C. Control D. Seed germinated

RESULTS CONT’D.

Plate 2: Showing the effect of fungi on Soybean germination.

Source DF F. oxysporum D. glycines

Treatment 5 12243.94** 7734.63**

Concentration 2 1076.67** 134.71

Days 4 120.00 73.26

Error 78 101.57 84.42

Total 89

RESULTS CONT’D

Table 4: Mean square effect on botanical treatment, concentration and inoculation days on F.oxysporum and D. glycines

** Highly significant.

Source DF MS

Concentration 2 983.85**

Days 4 111.85**

Organisms 1 0.43

Treatment 5 19089.21**

Concentration*Days 8 15.02

Concentration*Organisms 2 227.55**

Treatment * concentration 10 607.36**

Organisms*Days 4 81.41*

Treatment*Days 20 76.87**

Treatment*Organisms 5 889.36**

Concentration*Organism*Days 8 24.02

Treatment*Concentration*Days 40 22.75

Treatment*Concentration*Organisms 10 420.05**

Treatment*Organisms*Days 20 31.07

Error 40 21.29

Total 179

RESULTS CONT’DTable 5: Interactive effects of concentrration, pathogenic fungi, Treatment and Inoculation

days on mycelia growth on F.oxysporum and D. glycines

**Highly significant, *Significant.

16

RESULTS CONT’D

Control 1 Control 2

Zone of Inhibition

Plate 3: Mycelia growth inhibition of F. oxysporum with botanical extract at varying concentration

RESULTS CONT’D

Control 1 Control 2

Zone of Inhibition

Plate 4: Mycelia growth inhibition of D. glycines with botanical extract at varying concentration

CONCLUSION

The efficacy of the aqueous leaf extracts of the selected plant material could be

explored in the protection of Soybean seeds against pathogenic fungi especially

with the use of L. inermi and A. fimbriata which were very effective, therefore the

utilization as biocontrol agents is imperative.

DISCUSSION

The study revealed that A. niger and F. oxyporums are the most frequent

isolates. Microorganisms especially fungi are known to be the major cause of

market and field losses of crops (Onifade, 2000 and Brandyopadyay et al., 2005).

This work adds to the list of plants screened for antifungal activity significant to

crop protection. The four plants extract indicated inhibitory effects on F.

oxysporum and D. glycines.

It was also observed that the efficacy of the extract was dependent on

concentration.

L. inermis extract was found to be most effective against the two pathogenic

fungi tested at 5, 10 and 15g/ml and which conform with the report of Abdelraouf

et al., 2011, next to these is A. fimbriata (Salman et al., 2012), C. sinensis (Qian

and Nihorimbere, 2004) and least inhibition on D. metel. (Asma et al., 2013).

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