Chief EditorT. Mohapatra
Print ISSN 0367-8245
Online ISSN 0976-058X
NAAS Rating 5.20
Full Research Article
In-vitro Effect of Different Abiotic Stresses on the Growth and Sporulation of Colletotrichum gloeosporioides causing Anthracnose of Mango
- Email email@example.com
First Online 27-11-2021|
Methods: Among four different culture media tested, the highest radial growth and sporulation of the fungus were recorded in Oatmeal agar (OMA) (84 mm) followed by Conn’s agar (CA), Czapek Dox agar (CDA) and Potato dextrose agar (PDA). Among the different pH tested, pH 7.0 was found to be the best in supporting the good radial growth (69 mm) followed by pH 6.0 (56 mm), pH 5.5 (49 mm), pH 7.5 (43 mm) and pH 8.0 (37 mm). Among the various temperature tested, 25oC (69.32) was found to be the best followed by 20oC (52.53 mm), 30oC (65.23 mm) and 35oC.
Result: Among the fungicides tested, Zineb 68% + Hexaconazole 4% WP (avtar) was found best as the radial growth was observed to be 45, 41, 36, 32, 25 mm at 5, 10, 25, 50 and 100 ppm, respectively as compared to 80 mm in control. The fungicide Tricyclazole 18% + Mancozeb 62% WP (Merger) was found to be the least effective in checking the radial growth of C. gloeosporioides even at 100 ppm concentration.
MATERIALS AND METHODS
Standardization of media for the growth and sporulation of C. gloeosporioides
Four different fungal media was used to identify the status of C. gloeosporioides growth and sporulation. In this study, media such as Oatmeal agar (OMA), Potato dextrose agar (PDA), Conn’s agar (CA) and Czapek Dox agar (CDA) were screened to select the medium supporting the highest growth of the fungus. All the media were adjusted to pH-7.0 and sterilized at 15 lbs /inch2 for 20 min. In sterilized Petri plates, 18-20 ml of sterilized medium was poured. The plate was shaken uniformly and the medium in plates was allowed to solidify. These were inoculated by placing in the culture of the plate 5 mm mycelial disc having conidial growth cut from the margin of the 5-day old culture of the test fungus. Inoculated Petridishes was incubated at 27±2oC for 6 days. The radial growth was measured at the interval of 24 h till the 7th day. The medium, which supported the highest radial growth, was selected for further studies. For the sporulation study, a 5 mm mycelial disc of actively growing culture of C. gloeosporioides was dipped in sterilized distilled water about 5-10 times. About 10 µl spore suspension solution was then observed on the slide under the microscopic field. The numbers of spores were counted using standard methods for spore count.
Effect of different temperatures on the growth of C. gloeosporioides
Four temperature regimes viz. 20, 25, 30 and 35oC were selected to study the best temperature regime supporting the radial growth of the pathogen. These media were adjusted to pH 7.0 and then in sterilized Petri-plates, 18-20 ml of sterilized medium was poured. The plates were shaken uniformly and the medium in plates was allowed to solidify. After solidification of the medium in the plates, these were inoculated by placing in the center of the plate 5 mm mycelium disc having conidial growth cut from the margin of the 7-day old culture of the fungus. Inoculated Petri discs were kept in an incubator at different selected temperatures viz. 20, 25, 30 and 35oC for 7 days. The radial growth was measured after 24 hours at regular intervals for 7 days.
Effect of different pH on growth of C. gloeosporioides
Effect of different pH values viz., on Prepared different pH (5.5, 6.0, 7.0, 7.5 and 8.0) of PDB media adjusted by adding sodium hydroxide (NaOH) (0.1N) or hydrochloric acid (0.1N HCl) and additionally added 2% solidification agent agar with pH was measured using electrical pH meter before sterilization within autoclave at 121oC. Twenty 20 ml of sterilized media was poured into sterilized Petri plates. The plates were shaken uniformly and the medium in plates was allowed to solidify. After solidification of the medium in the plates, these were inoculated by placing in the center of the plate 5 mm mycelium disc having conidial growth cut from the margin of the 7 days old culture of Petri dish were kept in an incubator at 37±2oC for 7 days. The radial growth was measured after 24 hours at regular intervals for 7 days.
Evaluation of fungicides for the inhibition of growth of C. gloeosporioides
Five fungicides viz. Zineb 68% + Hexaconazole 4% WP (Avtar), Blastin (Tricyclazole WP.75), Tricyclazole 18% + Mancozeb 62% WP (Merger), Mancozeb 75% WP (Indofil M-45), Blitox-50 (Copper oxychloride) were evaluated for control of C. gloeosporioides in vitro for inhibition of radial growth on the media. The above fungicide were tried at 5 ppm, 10 ppm, 25 ppm, 50 and 100 ppm were prepared then sterilized at 15 lbs/ inch2 for 20 minutes and poured in sterilized Petri plates. The plates were shaken uniformly and the PDA containing the desired concentration of fungicide in plates was allowed to solidify. The plates were inoculated by placing a 5 mm mycelium disc having fungal growth cut from the margin of the 7 day’s old culture of the pathogen. Inoculated Petri dishes were incubated at 27±2oC and observations were recorded by measuring the colony diameter of the pathogen and check. and evaluated against C. gloeosporioides.
Treatment means were compared using ANOVA and the level of significance considered was p>0.01(Scheinpflug and Kuck, 1987).
RESULTS AND DISCUSSION
The characteristic symptoms are numerous oval or irregular vinaceous brown or deep brownish spots of various sizes scattered all over the leaf surface under damp conditions. The fungus grows rapidly forming elongated mars brown or mummy brown necrotic areas measuring 20-25 mm in diameter which when old becomes ruptured and blighted. They do not become much larger as the leaf grows but often become dry and fall out giving the older leaves a ‘shot hole’ appearance.
Effect of different media on radial growth of C. gloeosporioides
Results of the experiment revealed that among the four media Oatmeal agar was best (84 mm) supporting the good radial growth of the pathogen followed by Czapek’s dox agar and conn’s agar (Table 1). Oatmeal agar was selected for further studies of the pathogen.
Effect of different media on sporulation of C. gloeosporioides
It was clear from the results (Table 2) that high sporulation was observed in the case of Oatmeal agar media. Czapek Dox agar and Conn’s agar supported moderate sporulation. Low sporulation was observed in the case of PDA (Table 2).
Effect of different temperatures on radial growth of C. gloeosporioides
Results of the experiment revealed that among the four temperatures tested, 25oC was found best in supporting the good radial growth (69 mm) of C. gloeosporioides followed by 30oC (65 mm), 20oC (52 mm). The temperature regime of 35oC did not support the radial growth of the pathogen as only 12 mm radial growth was observed (Table 3). Temperature 25oC was selected for further studies of the pathogen.
Effect of different pH values on radial growth of C. gloeosporioides
Results of the experiment revealed that among five pH values, pH 7.0 was found best in supporting the good radial growth (65 mm) of C. gloeosporioides followed by pH 6.0 (56 mm), pH 5.5 (49 mm), pH 7.5 (43 mm) and pH 8.0 (37 mm) (Table 4). pH 7.0 was maintained in all further studies.
Effect of fungicides on the radial growth of C. gloeosporioides
All the fungicides tested were found effective in checking the radial growth of C. gloeosporioides. At all the concentrations tried, Zineb 68% + Hexaconazole 4% WP (Avtar) was found best as the radial growth was observed to be 45, 41, 36, 32, 25 mm at 5, 10, 25, 50 and 100 ppm respectively as compared to 80 mm in control. The fungicide Tricyclazole 18% + Mancozeb 62% WP (Merger) was least effective in checking the radial growth of C. gloeosporioides even at a 100 ppm concentration (Table 5).
In Conclusion, in vitro effect of various abiotic factors such as nutrient constitution media, temperature, pH against the growth performance of mango pathogen, colletotrichum gloeosporioides was studied. Spalding and Reeder, 1978 reported good growth of C. gloeosporioides on Pomegranate between 15-35oC with an optimum at 28oC. (Rangaswami and Mahadevan, 1999) Reported based on the growth of different isolates of C. gloeosporioides at different temperatures reported that isolation from Lucknow, Arambakam and Triuvur grow well at 25oC while isolating from Dapoli, Hessarghatta and Tumkur at 28oC and isolation from Hassan and Raichur at 30oC. (Russell, 1995) Recorded maximum growth of C. gloeosporioides at 25oC and 29oC respectively. The present study evaluated five different fungicides in various concentrations 5, 10, 25, 50 and 100 ppm. The fungicide Zineb 68% + Hexaconazole (Avtar) was found to be best than other treatments which were following the results of previous studies. The new fungicides were found to work well against the pathogen in the present study. (Jeffries et al., 1990) Conducted experiments to evaluate the effects of 10 fungicides formations and hyphal growth of c. gloeosporioides (Glomerella cingulata), the causal agent of persimmon anthracnose. The results showed that the fungicide has a distinct control effect against anthracnose. The best control way obtained with chlorothalonil, thiram and carbendazim. (McMillan, 1984) Reported that, unlike triazole fungicides, prochloraz was found to be very effective in controlling anthracnose disease. The fungicide also has been used in mango anthracnose control in many countries (Sangeetha and Rawal, 2009). (Ploetz and Prakash, 1997) Reported that systemic fungicides were important tools because they are capable of moving within a plant system. The introduction of benzimidazole fungicides such as benomyl, carbendazim and thiophanate-methyl in the early 1960s revolutionized disease control. Among the tested fungicides, tricyclazoles were found to be superior for controlling the incidence of pathogen (Hua et al., 2001) reported the effectiveness of different fungicides against C. gloeospori oides infecting large cardamom, the in vitro tests showed that the pathogen was highly sensitive to copper oxychloride 50 WP (0.3%) followed by mancozeb 75 WP (0.3%) and combined formulation of car-bendazim + mancozeb (12 + 63) WP (0.3%).
- Ann, P.J., Chen, M.F. and Hwang, R.C. (1997). Effects of Environmental Factors on Disease Incidence of Mango Anthracnose and Bacterial Black Spot. In: Proceedings of the Symposium on Climatic Effects on the Occurrence of Plant Disease and Insects; Society of Agrometereology. 29-40.
- Ekbote, S.D. (1994). Studies on anthracnose of mango (Mangiferae indica L.) caused by [Colletotrichum gloeosporioides (Penz.) Penz]. And Sacc. M. Sc. Thesis Submitted to University of Agriculture Sciences. Dharwad. 101.
- FAO. (2000). FAOSTAT online database at: http://www.fao.org/ default.htm.
- Hua, Y., Jiang, L., Lin, F., Sun, P. and Yu, W. (2001). Fungicides screening trail against persimmon anthracnose in lab. Forest Pest and Disease. 6: 11-13.
- Jeffries, P., Dodd, J.C., Jeger, M.J. and Plumbley, R.A. (1990). The biology and control of Colletotrichum species on tropical fruit. Plant Pathology. 39(3): 353-366.
- Kumar, R. and Rani, U.S. (2010). Epidemiological and nutritional factors on growth of Colletorichum gloeosporiodes. Annals of Plant Protection Science. 18: 159-163.
- McMillan, J.r. R.T. (1984). Control of mango anthracnose with foliar sprays. Proceeding of the Florida state Horticulture Society. 97: 344-345.
- Noiaium, S. and Soytong, K. (1999). Integrated Biological Control of Mango cv Choakanon. Proc. of the Sixth International Mango Symposium, April 6-9; Pattaya. Thailand: 13.
- Ploetz, R.C. and Prakash, Om. (1997). Foliar, Floral and Soil Borne Disease. In: The Mango: Production and Uses. CAB International, Wallingford, UK. 281-326.
- Prior, C, Elango, F. and Whitewell, A. (1992). Chemical Control of Colletotrichum Infection in Mangoes. In: Colletotrichum: Biology, Pathology and Control [Bailey J.A. and Jeger. M.J., Eds.], CAB International Oxon UK. 326-336.
- Rangaswami, G. and Mahadevan, A. (1999). Disease of Crop Plants in India. Prentice Hall of India Pvt Ltd., New Delhi. 60-79.
- Russell, P.E. (1995). Fungicide Resistance: Occurrence and Management. The Journal of Agricultural Science. 124(3): 317-323.
- Saju, K.A., Deka, T.N., Gupta, U., Biswas, A.K. and Sudhar-shan, M.R. (2012). In vitro evaluation of biocontrol agents, botanicals and fungicides against Colletotrichum gloeosporioides infecting large cardamom. Pl. Dis. Res. 27(1): 49-53.
- Sangeetha, C.G. and Rawal, R.D. (2009). Temperature requirement of different isolate of Colletotrichum gloeosporioides isolated from mango. American-Eurasian Journal of Scientific Research. 4(1): 20-25.
- Saxena, A.K. (2002). Anthracnose of Pomegranate Biology of pathogen, epidemiology and disease control Ph. D. thesis submitted to Maharishi Dayanad Saraswathi University Ajmer Rajasthan. 232.
- Scheinpflug, H. and Kuck, K.H. (1987). Sterol Biosynthesis Inhibiting Piperazine, Pyridine, Pyrimidine and Azole Fungicides. In: Modern Selective Fungicides - Properties, Applications, Mechanisms of Action (Ed, by H. Lyr). VEB Gustav Fischer, Jena. 173-204.
- Spalding, D.H. and Reeder, W.F. (1978). Controlling market disease of mangos with heated benomyl. Proc Fla State Horticulture Society. 91: 186-187.
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.