Refine your search
Collections
Co-Authors
Journals
Year
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Venugopala, K. M.
- Strategic Eco-Friendly Management of Post-Harvest Fruit Rot in Papaya Caused by Colletotrichum gloeosporioides
Abstract Views :265 |
PDF Views:127
Authors
Affiliations
1 Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
1 Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
Source
Journal of Biological Control, Vol 33, No 3 (2019), Pagination: 225-235Abstract
Papaya (Carica papaya L.) is one of the important fruits cultivated in the tropical and subtropical regions are widely prone to the post-harvest anthracnose disease. A sum of ten isolates of Colletotrichum gloeosporioides were collected and identified through morphological and molecular method. Morphological characterization of the isolates revealed a wide variation among the isolates with respect to colony colour, topography, margin, pigmentation and zonation. The ITS gene region and the specific primer, MKCgF coupled with ITS-4, which generated amplicons of size 560 bp and 380 bp respectively for C. gloeosporioides. The amplicon (560 bp) of virulent strain Cg1 was partially sequenced [MF062699]. In order to formulate eco-friendly management practices, the in vitro screening of different biocontrol agents viz., Bacillus spp., Pseudomonas spp., plant extracts and essential oils were tested against the C. gloeosporioides. Based on the in vitro efficacy, Bacillus sp. (BSP1) and cinnamon oil were selected and further tested under field conditions as pre harvest spray and after harvest as fruit dipping. The experimental results revealed that pre-harvest spray with Bacillus sp. (BSP1) (5%) + post-harvest dipping with cinnamon oil (0.1%) recorded the lowest PDI of 3.25 when compared to control (70.36) and also increased the shelf life of papaya fruits up to 14 days. Our results show that this novel methodology of use a combination of biocontrol agent as pre-harvest spray and essential oils as post-harvest fruit dipping will protect against post-harvest anthracnose of papaya and use of chemical fungicides can be avoided.
Keywords
Anthracnose, Bacillu spp, Colletotrichum gloeosporioides, Cinnamon Oil, Formulation, Thyme Oil.Full Text
References
- Agres. 1994. Statistical Software Version 3.01. Pascal International Software Solutions, USA.
- Alvarez AM, Nishijima WT. 1987. Postharvest diseases of papaya. Plant Dis. 71: 681-686. https://doi.org/10.1094/PD-71-0681
- Anonymous. 2017. National Horticulture database. National Horticulture Board, Govt. of India, Gurgaon, India. pp. 182. www.nhb.gov.in
- Bose SK, Sindhar GS, Pande BN. 1973. Studies on the dieback disease of mango in the Tarai region of Kumaon. Prog Hort. 5: 41-53.
- Brankica T, Slavica G, Jovana H, Milica M, Mila G, Goran D, Marija S. 2013. Development of a thyme essential oil formulation and its effect on Monilinia fructigena. Pestic Phytomed. 28: 273-280. https://doi.org/10.2298/PIF1304273T
- Dickman MB, Alvarez AM. 1983. Latent infection of papaya caused by Colletotrichum gloeosporioides. Plant Dis. 67: 748-750. https://doi.org/10.1094/PD-67-748
- Dennis C, Webster J. 1971. Antagonistic properties of species groups of Trichoderma: production of non-volatile antibiotics. Trans Br Mycol Soc. 57: 25-39. https://doi.org/10.1016/S0007-1536(71)80077-3
- Hofmeyr JDJ. 1938. Genetical studies of Carica papaya L. South Afr J Sci. 35: 300-304.
- Jeffries P, Dodd JC, Jeger MJ, Plumbley RA. 1990. The biology and control of Colletotrichum species on tropical fruit crops. J Plant Pathol. 39: 343-366. https:// doi.org/10.1111/j.1365-3059.1990.tb02512.x
- Joshi PV, Kadam JJ, Joshi MS, Pawar SV. 2015. Symptomatology, pathogenicity, host range and cultural study of Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. causing tip blight of jackfruit (Artocarpus heterophyllus L.). Periodic Res. 4: 1-5.
- Kagale S, Marimuthu T, Thayumanavan B, Nandakumar R, Samiyappan R. 2004. Antimicrobial activity and induction of systemic acquired resistance in rice by leaf extract of Datura metal against Rhizoctonia solani and Xanthomonas oryzae pv. oryzae. Physiol Mol Plant Pathol. 65: 91. https://doi.org/10.1016/j.pmpp.2004.11.008
- Kamle M, Pandey BK, Kumar P, Muthu Kumar M. 2013. A species-specific PCR based assay for rapid detection of mango anthracnose pathogen Colletotrichum gloeosporioides Penz. and Sacc. J Plant Pathol Microbiol. 4: 6. https://doi.org/10.4172/2157-7471.1000184
- Kelebek H, Selli S, Gubbuk H, Gunes E. 2015. Comparative evaluation of volatiles, phenolics, sugars, organic acids and antioxidant properties of Sel-42 and Tainung papaya varieties. Food Chem. 173: 912-919. https://doi.org/10.1016/j.foodchem.2014.10.116 PMid:25466106
- Kessmann H, Staub T, Hofmann C, Maetzke T, Herzo J. 1994. Induction of systemic acquired disease resistance in plants by chemicals. Ann Rev Phytopathol. 32: 439-459. https://doi.org/10.1146/annurev.py.32.090194.002255 PMid:18479201
- Kulshrestha S, Chaturvedi S, Jangir R, Agrawal K. 2015. In vitro Evaluation of antibacterial activity of some plant leaf extracts against Xanthomonas axonopodis pv. phaseoli isolated from seeds of lentil (Lens culinaris Medik). Intern Res J Biol Sci. 4: 59-64.
- Macedo TG. 2004. Chemical control and hydrothermal of anthracnose in fruits of mamoiro (Carica papaya) in the post-harvest. Brazilian J Fruticul. 28: 131-133.
- Mahesh B, Satish S. 2008. Antimicrobial activity of some important medicinal plants against plant and human pathogens. World J Agrl Sci. 4: 839-843.
- Manikandan R, Saravanakumar D, Rajendran L, Raguchander T, Samiyappan R. 2010. Standardization of liquid formulation of Pseudomonas fluorescens Pf1 for its efficacy against Fusarium wilt of tomato. Biol Control. 54: 83-89. https://doi.org/10.1016/j.biocontrol.2010.04.004
- Murray MG, Thompson WF. 1980. Rapid isolation of high molecular weight plant DNA. Nucleic Acids Res. 8(19): 4321-4325. doi: 10.1093/nar/8.19.4321 https://doi.org/10.1093/nar/8.19.4321 PMid:7433111 PMCid:PMC324241
- Muthulakshmi P, Ragavi B, Parthasarathy S. 2017. Influence of abiotic factors on the growth of Colletotricum musae causing post-harvest anthracnose disease in banana. Int J Agric Sci Res. 7:121-128.
- Narayanan P, Parthasarathy S, Rajalakshmi J, Arunkumar P, Vanitha S. 2016. Systemic elicitation of defense related enzymes suppressing Fusarium wilt in mulberry (Morus spp.). Afr J Microbiol Res. 10: 813-819. https://doi.org/10.5897/AJMR2015.7900
- Nene YL, Thapliyal PN. 1982. Fungicides in Plant Diseases Control. Oxford and IBH Pubishing Co Pvt. Ltd., New Delhi. pp.163.
- Obon JM, Diaz-Garcia MC, Castellar MR. 2011. Red fruit juice quality and authenticity control by HPLC. J Food Compos Anal. 6: 760-771 https://doi.org/10.1016/j.jfca.2011.03.012
- Pandey A, Yadava LP, Manoharan M, Chauhan UG, Pandey BK. 2012. Effectiveness of cultural parameters on the growth and sporulation of Colletotrichum gloeosporioides causing anthracnose disease of mango (Mangifera indica L). J Biol Sci. 12: 123-133. https:// doi.org/10.3844/ojbsci.2012.123.133
- Pandey DK, Tripathi RN, Tripathi NN. 1982. Antifungal activity in some seed extracts. Environ India. 4: 164167.
- Parthasarathy S, Rajalakshmi J, Narayanan P, Arunkumar K, Prabakar K. 2017. Bio-control potential of microbial antagonists against post-harvest diseases of fruit crops: A review. Res Rev: J Bot Sci. 6: 17-23.
- Parthasarathy S, Rajalakshmi J, Narayanan P, Prabakar K.2016a. Botanicals in eco-friendly post-harvest disease management. Innovative Farm. 1: 67-71.
- Parthasarathy S, Thiribhuvanamala G, Subramanium KS, Prabakar K. 2016b. Bacterial antagonists and hexanalinduced systemic resistance of mango fruits against Lasiodiplodia theobromae causing stem-end rot. J Plant Interact. 11: 158-166. https://doi.org/10.1080/1742914 5.2016.1252068
- Paull RE, Nishijima W, Reyes M, Cavaletto C. 1997. Postharvest handling and losses during marketing of papaya (Carica papaya). Postharvest Biol Technol. 11: 165-179. https://doi.org/10.1016/S0925-5214(97) 00028-8
- Rangaswami G. 1958. An agar block technique for isolating soil micro-organisms with special reference to Pythiaceous fungi. Sci Culture 24: 85-94.
- Ravindran C, Kohli, Anshuman, Murthy and Srinivas. 2007. Fruit production in India. Chronica Horticulturae 42: 21-26.
- Rahman MA, Kadhir J, Mahmud TMM, Abdul R, Begum S. 2007. Screening of antagonistic bacteria for biocontrol activities on Colletotrichum gloeosporioides in papaya. Asian J Plant Sci. 6: 12-20. https://doi.org/10.3923/ajps.2007.12.20
- Roopadevi, Jamadar MM. 2016. In-vitro bioassay of different fungicides against anthracnose of green gram caused by Colletotrichum truncatum (Schw.) Andrus and Moore. Environ Ecol. 34: 132-135.
- Rufino MS, Alves RE, de Brito ES, Perez-Jimenez J, SauraCalixto F, Mancini-Filho J. 2010. Bioactive compounds and antioxidant capacities of 18 non-traditional tropical fruits from Brazil. Food Chem. 121: 996-1002.https:// doi.org/10.1016/j.foodchem.2010.01.037
- Siddiqui Y, Ali A. 2014. Colletotrichum gloeosporioides (Anthracnose). Post-harvest Decay 4: 337-364. https:// doi.org/10.1016/B978-0-12-411552-1.00011-9
- Spadaro D, Gullino ML. 2004. State of the art and future prospects of the biological control of postharvest fruit disease. Intern J Food Microbiol. 91:185-194. https:// doi.org/10.1016/S0168-1605(03)00380-5
- Stracieri J, Pereira FD, da Silveira AL, Magalhães HM, de Goes A. 2016. Morphocultural and molecular characterization of papaya tree Colletotrichum spp. Afr J Agrlc Res. 11: 1755-1764. https://doi.org/10.5897/AJAR2016.10868
- Sutton BC. 1992. The genus Glomerella and its anamorph Colletotrichum. pp. 1-26. In: Bailey JA, Jeger MU (Eds.). Colletotrichum biology, pathology and control. CAB International, Wallingford.
- Taale E, Savadogo A, Zongo C, Somda MK, Sereme SS, Karou SD, Soulama I, Traore, AS. 2015. Biochemical and molecular characterization of strains isolated bacteria from Soumbala. Int J Adv Res Biol Sci. 2: 279-290.
- Vanitha S. 2010. Developing new formulation using plant oils and testing their physical stability and antifungal activity against Alternaria chlamydospora causing leaf blight in Solanum nigrum. Res J Agric Sci. 1: 385-390.
- Vincent JM. 1947. Distortion of fungal hyphae in the presence of certain inhibitors. Nature 150: 850. https:// doi.org/10.1038/159850b0 PMid:20343980
- Udomkun P, Nagle M, Mahayothee B, Nohr D, Koza A, Müller J. 2014. Influence of air drying properties on non-enzymatic browning, major bio-active compounds and antioxidant capacity of osmotically pre-treated papaya. LWT-Food Sci Technol. 60: 914-922. https://doi.org/10.1016/j.lwt.2014.10.036
- White TJ, Bruns TD, Lee SB and Taylor JW. 1990. Amplification and Direct Sequencing of Fungal Ribosomal RNA Genes for Phylogenetics. pp. 315-322. In: Innis MA, Gelfand DH, Sninsky JJ and White TJ (Eds). PCR protocols: A guide to methods and applications. Academic Press, New York.
- Xiao CL, Mac Kenzie SJ, Legard DE. 2004. Genetic and pathogenic analyses of Colletotrichum gloeosporioides from strawberry and non-cultivated hosts. Phytopathology. 94: 446-453. https://doi.org/10.1094/PHYTO.2004.94.5.446 PMid:18943762
- Diversity of cry Genes Occurring in the North East
Abstract Views :282 |
PDF Views:121
Authors
R. Rangeshwaran
1,
V. Velavan
2,
Satendra Kumar
2,
V. Apoorva
2,
K. M. Venugopala
2,
A. N. Shylesha
2,
G. Sivakumar
2
Affiliations
1 ICAR-National Bureau of Agricultural Insect Resources, H.A. Farm Post, Hebbal, Bellary Road, Bengaluru – 560024, Karnataka, IN
2 ICAR-National Research Centre for Banana, Thogaimalai Rd, Podavur, Thiruchirapalli – 620102, Tamil Nadu, IN
1 ICAR-National Bureau of Agricultural Insect Resources, H.A. Farm Post, Hebbal, Bellary Road, Bengaluru – 560024, Karnataka, IN
2 ICAR-National Research Centre for Banana, Thogaimalai Rd, Podavur, Thiruchirapalli – 620102, Tamil Nadu, IN
Source
Journal of Biological Control, Vol 33, No 3 (2019), Pagination: 242-252Abstract
The search for new Bacillus thuringiensis (Bt) strains is a continuous process and researchers are now focusing on finding toxin proteins that are toxic to pests of insect orders that are not reported. In the present study soil and insect cadaver samples were collected from North East India comprising the states of Assam, Tripura and Mehhalaya and native Bt were isolated using standard protocols. At total of 30 Bt isolates were purified and characterized. Various types of crystal morphology were encountered that included bipyramidal, cuboidal, square, rhomboid, spherical and irregular. PCR analysis showed that diverse cry genes were expressed. The cry genes identified were Lepidoptera, Coleoptera and Diptera specific. Detected genes included cry1Ac, cry2A, cry4A, cry10A, cry16A, cry17A, cry19A, cry30Aa, cry44Aa, cry11A, cry4B, cry12A, cry8A and cry7A. Many of them were positive for Vip3A protein. The coleopteran specific Bt were evaluated against Sitophilus oryzae and Callosobruchus chinensis and NBAIR-AgBt6 was found to be toxic. The isolates are being further evaluated for use as biopesticides.Keywords
Bacillus thuringiensis, Bioassay, Cry Genes, Diversity, North East.Full Text
References
- Aly AH Nariman. 2007. PCR Detection of cry genes in local Bacillus thuringiensis Isolates. Aust J Basic Appl Sci. 1(4): 461-466.
- Aronson AI. 1994. Bacillus thuringiensis and its use as biological insecticide. Plant Breed Rev. 12: 19-45.
- Asokan R, Mahadeva Swamy HM, Birah A, Geetha G Thimmegowda. 2013. Bacillus thuringiensis Isolates from Great Nicobar Islands. Curr Microbiol. 66: 621626.
- Baig DN, Mehnaz S. 2010. Determination and distribution of cry-type genes in halophilc Bacillus thuringiensis isolates of Arabian Sea sedimentary rocks. Microbiol Res. 165(5):376-83.https://doi.org/10.1016/j.micres.2009.08.003 PMid:19850456
- Baig DN, Bukhari DA, Shakoori AR. 2010. Cry genes profiling and the toxicity of isolates of Bacillus thuringiensis from soil samples against American bollworm, Helicoverpa armigera. J Appl Microbiol. 109(6): 1967-1978. https://doi.org/10.1111/j.13652672.2010.04826.x PMid:20738439
- Barloy F, Lecadet M-M, Delécluse A. 1998. Distribution of clostridial cry-like genes among Bacillus thuringiensis and Clostridium strains. Curr Microbiol. 36: 232-237. https://doi.org/10.1007/s002849900300 PMid:9504991
- Ben-Dov E, Zaritsky A, Dahan E, Barak Z, Sinai R, Manasherob R, A Khamraev, E Troitskaya, Dubitsky A, Berezina N, Margalith Y. 1997. Extended screening by PCR for seven cry-group genes from field-collected strains of Bacillus thuringiensis. Appl Environ Microbiol. 63: 4883-90.
- Bourque SN, Valero JR, Mercier J, Lavoie MC, Levesque RC. 1993. Multiplex polymerase chain reaction for detection and differentiation of the microbial insecticide Bacillus thuringiensis. Appl Environ Microbiol. 59:(2): 523-527
- Bravo A, Sarabia S, Lopez L, Ontiveros H, Abarca C, Ortiz A, Soberon M, Quintero, R. 1998. Characterization of cry genes in a Mexican Bacillus thuringiensis strain collection. Appl Environ Microbiol. 64: 4965-4972.
- Chaubey MK. 2011. Combinatorial action of essential oils towards pulse beetle Callosobruchus chinensis Fabricius (Coleoptera: Bruchidae). Int J Agri Res. 6: 511-516. https://doi.org/10.3923/ijar.2011.511.516
- Chen ML, Chen PH, Pang JC, Chia-Wei Lin CW, Chin-Fa HC, Hau-Yang T. 2014. The correlation of the presence and expression levels of cry genes with the insecticidal activitiesagainst Plutella xylostella for Bacillus thuringiensis strains. Toxins 6: 2453-2470. https://doi.org/10.3390/toxins6082453 PMid:25153253 PMCid:PMC4147593
- Ejiofor AO, Johnson T. 2002. Physiological and molecular detection of crystalliferous Bacillus thuringiensis strains from habitats in the South Central United States. J Ind Microbiol Biotechnol. 28: 284-290 https://doi.org/10.1038/sj/jim/7000244 PMid:11986933
- Federiei BA, Luthy P, Ibarra JE. 1990. Parasporal body of Bacillus thuringiensis israelensis: Structure, protein composition and toxicity. p. 349. In: de Barjac H and Sutherland DJ (Eds.). Bacterial control of mosquitoes and black flies. New Brunswick, Rutgers University Press. https://doi.org/10.1007/978-94-011-5967-8_3
- Head G. 2005. Assessing the influence of Bt crops on natural enemies. Second Inter. Symp. on Biol. Control of Arthropods. Davos, Switzerland, Sept., 12-16.
- Hofte H, Whiteley HR. 1989. Insecticidal crystal proteins of Bacillus thuringiensis. Microbiol. Rev. 53: 242-255.
- Ito T, Ikeya T, Sahara K, Bando H. and Shin-ichiro A. 2006. Cloning and expression of two crystal protein genes, Cry30Ba1 and Cry44Aa1, obtained from a highly mosquitocidal strain, Bacillus thuringiensis subsp. entomocidus. Appl Environ Microbiol. 72:(8): 5673-5676. https://doi.org/10.1128/AEM.01894-05 PMid:16885329 PMCid:PMC1538732
- Konecka E, Baranek J, Hrycak A, Kaznowski A. 2012. Insecticidal activity of Bacillus thuringiensis Strains isolated from soil and water. Scientific World J. 2012: 1-5.
- Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. 1951. Protein measurement with the folin phenol reagent. J Biol Chem. 193: 265-75.
- Md. Abdur Rashid, Bhuiyan Al Sazzad, Rowshan Ara Begum, Reza Md. Shahjahan. 2012. Mortality effect of Bt extracts and esterase variability in three stored grain insects: Callosobruchus chinensis, Sitophilus granarius and Tribolium castaneum. Int J Agric Food Sci. 2(4) : 158-163.
- Morris ON, Converse V, Kanagaratnam P, Cote JC. 1998. Isolation, characterization, and culture of Bacillus thuringiensis from soil and dust from grain storage bins and their toxicity for Mamestra configurata (Lepidoptera: Noctuidae). Can Entomol. 130: 515-537. https://doi.org/10.4039/Ent130515-4
- Nazarian A, Jahangiri R, Jouzani GS, Seifinejad A, Soheilivand S, Bagheri O, Keshavarzi M, Alamisaeid K. 2009. Coleopteran-specific and putative novel cry genes in Iranian native Bacillus thuringiensis collection. J Invertebr Pathol. 102: 101-109. https://doi.org/10.1016/j.jip.2009.07.009 PMid:19631215
- Porcar M, Juarez-Perez VP. 2003. PCR-based identification of Bacillus thuringiensis pesticidal crystal genes. FEMS Microbiol Rev. 26(5): 419-32. https:// doi.org/10.1111/j.1574-6976.2003.tb00624.x PMid:12586389
- Quesada-Moraga E, Garcıa-Tovar E, Valverde-Garcıa P, Santiago-Alvarez C. 2004. Isolation, geographical diversity and insecticidal activity of Bacillus thuringiensis from soils in Spain. Microbiol Res. 159:(2004): 59-71. https://doi.org/10.1016/j.micres.2004.01.011 PMid:15160608
- Ramalakshmi A, Udayasuriyan V. 2010. Diversity of Bacillus thuringiensis isolated from Western Ghats of Tamil Nadu State, India. Curr Microbiol. 61(1): 13-8. doi: 10.1007/ s00284-009-9569-6. https://doi.org/10.1007/s00284-009-9569-6 PMid:20033169.
- Rangeshwaran R, Velavan V, Frenita DL, Surabhi Kumari, Shylesha AN, Mohan M, Satendra Kumar and Sivakumar G. 2016. Cloning, expression and bioassay of Vip3A protein from an indigenous Bacillus thuringiensis isolate. J Pure Appl Microbiol. 10(2): 1533-1539
- Salehi Jouzani G, Seifinejad A, Saeedizadeh A, Nazarian A, Yousefloo M, Soheilivand S, Mousivand M, Jahangiri R, Yazdani M, Amiri RM, Akbari S.2008. Molecular detection of nematicidal crystalliferous Bacillus thuringiensis strains of Iran and evaluation of their toxicity on free-living and plant-parasitic nematodes. Can J Microbiol. 54: 812-822. https://doi.org/10.1139/W08-074 PMid:18923549
- Sambrook J, Fritsch EF, Maniatis T. 1989. Molecular cloning: a laboratory manual. 2nd edition. Cold Spring ndHarbor Laboratory, Cold Spring Harbor, N.Y.
- Santana MA, Moccia-V CC, Gillis AE. 2008. Bacillus thuringiensis improved isolation methodology from soil samples. J Microbiol Methods 75:(2): 357-8. doi: 10.1016/j.mimet.2008.06.008. https://doi.org/10.1016/j.mimet.2008.06.008 PMid:18619500
- Schnepf E, Crickmore N, Van Rie J, Lereclus D, Baum J, Feitelson J, Zeigler DR, Dean DH. 1998. Bacillus thuringiensis and its pesticidal crystal proteins. Microbiol Mol Biol Rev. 62: 775-806.
- Thammasittirong A, Attathom T. 2008. PCR-based method for the detection of cry genes in local isolates of Bacillus thuringiensis from Thailand. J Invertebr Pathol. 98: 121-126. https://doi.org/10.1016/j.jip.2008.03.001 PMid:18407288
- Travers RS, Martin PA, Reichelderfer CF. 1987. Selective process for efficient isolation of soil Bacillus spp. Appl Environ Microbiol. 53: 1263-1266.
- Uribe D, Martinez W and Ceron J. 2003. Distribution and diversity of cry genes in native strains of Bacillus thuringiensis obtained from different ecosystems from Colombia. J Invertebr Pathol. 82: 119-127. https://doi.org/10.1016/S0022-2011(02)00195-7
- Van Frankenhuyzen K (2009) Insecticidal activity of Bacillus thuringiensis crystal proteins. J Invertebr Pathol. 101: 1-16. https://doi.org/10.1016/j.jip.2009.02.009 PMid:19269294
- Vidal-Quist JC, Castañera P. and González-Cabrera J. 2009. Diversity of Bacillus thuringiensis strains isolated from citrus orchards in Spain and evaluation of their insecticidal activity against Ceratitis capitata. J Microbiol Biotechnol. 19(8): 749-759.
- Zothansanga, Lalhmachhuani N, Senthil Kumar N, Gurusubramanian G. 2011. PCR pathotyping of native Bacillus thuringiensis from Mizoram, India. Sci Vis. 11(3): 171-176.