ISOLATION AND IDENTIFICATION OF MAIN PATHOGENIC AND ANTAGONISTIC FUNGI ON DISEASED GINSENG CROP1)

By:Loekas Soesanto

Faculty of Agriculture, University of Jenderal Soedirman, P.O. Box 125, Purwokerto 53101. e-mail: lukas_262@yahoo.com

ABSTRAKPenelitian bertujuan untuk mengetahui dan mengidentifikasi jamur patogen

maupun antagonis, yang berkaitan erat dengan tanaman ginseng sakit. Penelitian dilakukan di laboratorium dengan metode deskriptif dari sampel bibit dan tanaman ginseng sakit, serta tanahnya. Hasil penelitian menunjukkan bahwa penyakit busuk batang tanaman ginseng terutama disebabkan oleh jamur Fusarium solani, Phytophthora sp., dan Curvularia sp. Jamur juga ditemukan pada sampel tanah. Jamur antagonis Trichoderma sp. yang diisolasi dari sampel tanah ginseng mampu menghambat pertumbuhan ketiga jamur patogen tersebut in vitro.

Kata kunci: Ginseng, Fusarium solani, Phytophthora sp., Trichoderma sp.

ABSTRACTResearch aimed at knowing and identifying pathogenic and antagonistic fungi

related closely with diseased ginseng crop. Descriptive method was used in the laboratory with samples from diseased ginseng seedling and crop, and its soil. Result of the research pointed out that stem rot disease of ginseng was caused by pathogenic fungi Fusarium solani, Phytophthora sp., dan Curvularia sp. The fungi was also found in soil sample. Antagonistic fungus, Trichoderma sp., isolated from ginseng soils could inhibit growth of these pathogenic fungi in vitro.

Key words: Ginseng, Fusarium solani, Phytophthora sp., Trichoderma sp.

INTRODUCTION

Ginseng (Panax spp.) is one of medicinal crops used in several countries. The

world ginseng production increases gradually as increasing ginseng plantation area

(Park and Kim, 1995 dalam Proctor, 1997). Ginseng production in South Korean has

reached 5000 ton.

1)Presented at the 1st International Conference of Crop Security 2005 at Brawijaya University, Malang September 20th – 22nd, 2005.

Ginseng has also been cultivated in several areas of Indonesia such as in

Banjarnegara and Wonosobo Regencies, and will be continued in other areas (Dewi

Anggraeni P., 2004. Komunikasi Pribadi). Recently, ginseng is still a new crop for

Indonesian farmers so that its special cultivation management is needed. It is

included ginseng diseases management at the level of seedlings, crop, and its soil.

Crop diseases is one of the main problems in developing ginseng because the

diseases can disturb sustainability of the crop. Causal agent of the ginseng diseases is

not reported yet before in Indonesia.

Although Nair (1995) reported that some pathogens causing ginseng diseases

in USA has already been found, knowledge of these pathogens in Indonesia is so

rare. The pathogens commonly found as soil-borne patogens were Pythium sp.,

Fusarium sp., Phytophthora sp., Rhizactonia sp., Sclerotinia panacis, and Alternaria

panax. The knowledge of the pathogens can be used for building a system of either

protection or management of the ginseng diseases. This research, therefore, was

aimed at knowing and identifying kinds of microorganism especially fungi, either

pathogen or antagonist, related closely with the ginseng diseases.

MATERIALS AND METHOD

The descriptive research was carried out at the Laboratory of Plant Diseases,

the Faculy of Agriculture, Jenderal Soedirman University from April 2004 up to

March 2005. Diseased ginseng seedlings and crops and its soil as materials were

taken from several locations of ginseng plantation such as Wonosobo, Banjarnegara,

Kebumen, and Pekalongan Regencies.

Preparation of media. Medium used was Potato Dextrose Agar (PDA)

modified by adding streptomycin, prepared aceptically in sterilized Petridishes.

Another medium used was Potato Dextrose Liquid (PDL) prepared in Erlenmeyer

(Tuite, 1969).

Isolation of diseased crop samples. Samples of the diseased crops were

surface sterilized with Clorox 1% then washed three times with sterile water and

finally dried on seterile filter papers. The materials were cut and replaced aceptically

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in Petridish containing PDA modified, and then incubated at room temperature for 5-

7 days (Waller et al., 1998).

Picture 1. Ginseng stem-end rot with symptoms of reddish brown color (arrow).

Isolation of soil samples. Ginseng soils were sampled randomize and

repeated three times per sample. One g of soil sample was added to 4 ml of sterile

water and then stirred by using Vortrex. Dillution method was used two times and

0.1 ml of soil suspention then spread onto PDA modified in Petridish with sterile L-

glass. Petridish was then incubated at room temperature for 3-5 days and continued

by fungal identification (Tuite, 1969).

Fungal identification. Pathogenic and antagonistic fungi was identified by

observing fungal morphology under microscope and some identification books such

as Barron (1972), Holliday (1980), Domsch et al. (1993), and Watanabe (1994).

Those isolates were recultured and stored for documentation and continued work.

Inhibition test. The antagonistic fungi obtained were tested their inhibition

in vitro by using dual culture. The fungi were placed on side of 3 cm in Petridish

containing PDA, and the pathogenic fungi were placed on the other side. The culture

was incubated for 5-7 days at room temperature.

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Data analyses. Data obtained were analyzed descriptively.

RESULT AND DISCUSSION

Isolation and Identification.

Result of isolation and identification from all samples showed some

pathogenic and antagonistic fungi.

1. Fusarium solani.

Result of identification pointed out that the main causal agent of ginseng stem-

end rot was F. solani (Mart.) App. et Wr. emend. Snyder & Hansen. This fungus

was dominantly found in all samples observed. The fungus formed microconidia

in form of tubular, 1-2 cells; macroconidia were slighly curve and two cells in

the center were tubular (Figure 2). This was in line with Watanabe (1994).

Colony of the fungus on PDA was white in color with thick aerial growth (Figure

3).

Figure 2. Macroconidia (A) and microconidia (B) of Fusarium solani (100 x).

This fungus caused stem-end and root rot disease. Symptom of the disease on

ginseng seedling and crop was redish (Figure 1 and 4). The symptom developed

from outside to inside of ginseng stem and caused the crop collapse. This was in

line with Agrios (1997).

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AB

Figure 3. Colony of Fusarium solani for 5 days on modified PDA.

Figure 4. The diseased ginseng seedling with stem-end rot symptom (arrow).

When the diseased stem was intersected, there will be brown color on ploem.

When all diseased ginseng seedlings were isolated and grown on agar media,

colony of the fungus grow with spesific form and color (Figure 3). According to

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Nair (1995) and Proctor (1997), one of ginseng pathogens is Fusarium spp. This

fungis caused ginseng yield loss in Korea for 50% (Oh, 1986 in Proctor, 1997).

2. Phytophthora sp.

Phytophthora sp. was also found at the diseased ginseng with symptom: in part

of the ginseng stem was redish color. Colony of this fungus on agar media was

redish violet with concentric growth. Sporangia were formed at the apex of

sporangiophor (Figure 5). This was in line with Proctor (1997) describing one of

pathogenic fungi on ginseng crops was Ph. cactorum. The fungus caused ginseng

yield loss in Korea for 2-30% (Oh, 1986 in Proctor, 1997). The fungus could also

destroy all ginseng plantation in several weeks when environmental condition

was appropriate for developing the disease.

Figure 5. Sporangia of Phytophthora sp. in chain (arrow) (100 x).

3. Curcularia sp.

Colony of this fungus on agar media was black in color. The fungus was isolated

from soil sample and from diseased ginseng stem. The fungus was not the main

pathogen for ginseng compared to other pathogenic fungi above.

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4. Trichoderma sp.

Colony of this fungus on agar media in the beginning was white in color and

spread over the media. After incubation for three days, the colony later on

become greenish to light green in color with concentric growth and then formed

dark green. This was in line with Domsch et al. (1993).

Inhibition Test

Based on the test, the antagonistic fungus Trichoderma sp. could be able to

inhibit growth of the pathogenic fungi either Fusarium sp., Phytophthora sp., or

Culvularia sp. (Figure 6 and 7). The antagonist had mechanism of antibiosis and

micoparasitism. This was caused by formation of inhibition zone and inhibited

growth of pathogenic fungi colony. The antagonist could also overgrow on the

pathogen when incubation period was prolonged.

Figure 6. Inhibition of Trichoderma sp. on Curvularia sp. (A) and Phytophthora sp. (B) in vitro.

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A B

Figure 7. Inhibition of Trichoderma sp. on Fusarium solani (A, B, and D) and Curvularia sp. (C) in vitro.

The antagonist Trichoderma sp. could be used as a candidate of biological

control agent for ginseng pathogen in the future. This was needed continued research

for optimum result.

CONCLUSION

Stem-end rot of ginseng was mainly caused by Fusarium solani and

Phytophthora sp. Antagonistic fungus Trichoderma sp. resulted from isolation and

identification could be able to inhibit growth of the pathogenic fungi in vitro.

REFERENCES

Agrios, G.N. 1997. Plant pathology,4th ed. Academic Press, New York. Pp. 352-353.Barron, G.L. 1972. The genera Hyphomycetes from Soil. Robert E. Krieger

Publishing Company, New York. 364 pp.Domsch, K.H., W. Gams, and T-H. Anderson. 1993. Compendium of Soil Fungi, vol.

1, IHW-Verlag, Eching. 859 pp.Holliday, P. 1980. Fungus Diseases of Tropical Crops. Cambridge University Press,

Cambridge.

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A

B

C

D

Nair, V.M.G. 1995. Advances in Ginseng Research (Panax spp). Its Diseases and the Need for the Preservation of Germplasm of Wild, Medicinal, Aromatic, and Spice Species. (On-line). http://www.metla.fi/iufro/iufro95abs/d5pap137.htm diakses 26 Pebruari 2005.

Proctor, J.T.A. 1997. Ginseng: Old Crop, New Directions. (On-line). http://www.hort.purdue.edu/newcrop/proceedings1996/v3-565.html diakses 26 Pebruari 2005.

Tuite, J. 1969. Plant Pathological Methods: Fungi and Bacteria. Burgess Publishing Company, Minneapolis. 239 pp.

Waller, J.M., B.J. Ritchie, and M. Holderness. 1998. Plant Clinic Handbook. CAB International. Wallingford.

Watanabe, T. 1994. Pictorial Atlas of Soil and Seed Fungi, Morphologies of Cultured Fungi and Key to Species. Lewis Publisher, Boca Raton. 411 pp.

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