AUTHOR: Kinlay Tshering
The taxonomy and diversity of Colletotrichum capsici was validated by morphological characters (conidia shape & size, colony characteristics, appressoria size) and molecular analysis using ISSR (Intersimple sequence repeats) markers with the objectives to adopt ISSR technique to assess the level of genetic variation among C. capsici isolates, to determine if the genetic variation among isolates corresponded with variation in morphological traits, and to determine if differentiation among C. capsici isolates based on morphological or ISSR variation was related to the host from which the isolates were collected. Morphological characters were quite variable within the species. Molecular analysis revealed that there was a genetic diversity with Thai isolates from Capsicum annuum being more similar than the other isolates from Queensland collected from other hosts like sugar apple, soy bean, etc. The phylogenetic groupings of C. capsici based on ISSR polymorphism did not appear to be congruent with morphological pattern and the rate of growth of isolates in culture. Further molecular analysis with a larger samples from a range of countries are required to determine if the clustering based on geographic origin and host plant is occurring. A high degree of molecular variability indicated that ISSR markers can be well utilized for the intraspecific characterization of C. capsici.
Colletotrichum capsici, ISSR, Morphology, Molecular variability, Capsicum annuum
Bernstein, B., Zehr, E. I. & Dean, R. A. (1995). Characteristics of Colletotrichum from peach, apple, pecan and other hosts. Plant Disease 79(5) : 478-482.
Blair, M. W., Panaud, O. & McCouch, S. R.(1999). Inter-simple sequence repeats (ISSR) amplification for analysis of microsatellite motif frequency and fingerprinting in rice (Oryza sativa L.). Theoretical and Applied Genetics 98: 780-792.
Chacko, R. J., Weidemann, G. J., TeBeest, D. O. & Correl, J. C. (1994): The use of compatibility and heterokaryosis to determine potential asexual gene exchange in Colletotrichum gloeosporioides. Biological Control 4 : 382–389.
Ciser, R., Spiegel, F. W., TeBeest, D. O. & Trout, C. (1994). Evidence of mating between isolates of Colletotrichum gloeosporioides with different host specificities. Current Genetics 25 : 330-335.
Fabre, J. V., Julien, J., Parisot, D. & Dron, M. (1995). Analysis of diverse isolates of Colletotrichum lindemuthianum infecting common bean using molecular markers. Mycological Research 99 : 429-435.
Hawksworth, D. L. (1974). Mycologist’s Handbook. Commonwealth Mycological Institute, Kew, Surrey, England. 231 pp.
Holiday, P. (1980). Fungus diseases of tropical crops. Cambridge University Press, Cambridge.
Katan, T. (2000). Vegetative compatibility in Colletotrichum. In: Prusky, D., Freeman, S. & Dickman, M. B. (eds.). Colletotrichum: Host specificity, pathology and host-pathogen interaction. pp. 145-179. The American Phytopathological Society, St. Paul, MN.
Lu, G., Cannon, P. F., Reid, A & Simmons, C. M. (2004). Diversity and molecular relationships of endophytic Colletotrichum isolates from the Iwokrama Forest Reserve, Guyana. Mycological Research 108 : 53–63.
Maclean, D. J., Braithwaite, K. S., Manners, J. M. & Irwin, J. A. G. (1993). How do we identify and classify fungal plant pathogens in the era of DNA analysis? Advances in Plant Pathology 10 : 208-244.
Nagaoka, T & Ogihara, Y.(1997). Applicability of inter-simple sequence repeat polymorphisms in wheat for use as DNA markers in comparison to RFLP and RAPD markers. Theoretical and Applied Genetics 94 (5) : 597 – 602.
O’Neill, N. R., van Berkum, P, Lin, J. J., Kuo, J., Ude, G. N., Kenworthy, W. & Saunders, J. A.(1997). Application of amplified restriction fragment length polymorphism for genetic characterization of Colletotrichum pathogens of alfalfa. Phytopathology 87 : 745-750.
Photita, W., Taylor, P.W.J., Ford, R., Lumyong, P., McKenzie, E. H. C., Hyde, K. & Lumyong, S.(2005). Morphological and molecular characterization of Colletotrichum species from herbaceous plants in Thailand. Fungal Diversity 18 : 117-133.
Pring, R. J., Nash, C., Zakaria, M. & Bailey, J. A. (1995). Infection process and host range of Colletotrichum capsici. Physiological and Molecular Plant Pathology 46 : 137-152.
Sharma, P. N., Kaur, M., Sharma, O. P., Sharma, P. & Pathanja, A.(2005). Morphological, pathological and molecular variability in Colletotrichum capsici, the cause of fruit rot of chillies in the subtropical region of North-western India. Phytopathology 153 : 232-237.
Smith, B. J. & Black, L. L. (1990). Morphological, cultural and pathogenic variation among Colletotrichum species isolated from strawberry. Plant Disease 74 : 69-76.
Sutton, B. C., (1992). The genus Glomerella and its anamorph Colletotrichum. In: Bailey, J. A. & Jeger, M. J. (eds.). Colletotrichum: Biology, pathology and control. CAB International, Wallingford. pp. 128.