Current projects:
Genetics and population genetics of P. infestans
Populations of P. infestans in much of the world have recently been modified dramatically by major migrations, such that populations previously present in the USA and Canada , Europe, South America and Asia have been displaced by introduced strains. We documented these changes throughout the 1990s and into the 21st century. Previously populations in these locations were strongly clonal, asexual, and dominated by a single clonal lineage of P. infestans. Now, in some locations populations are sexual and highly diverse, and in other locations there is the potential for populations to become sexual. The new populations have made late blight significantly more problematic throughout much of the world. We documented these migrations and compared derivative populations with the source population in central Mexico . The current population of P. infestans in the USA is completely different from that of 20 years ago, but it is still strongly clonal and still asexual. Our current effort is to analyze populations in the USA , to be vigilant for any evidence of sexual reproduction. Oospores are the result of sexual reproduction and are ecologically important because (in addition to producing new genotypes) these enable survival of P. infestans in the absence of a living host – otherwise not possible.
Selected Publications:
Elansky, S., Smirnov, A., Dyakov, Y., Dolgova, A., Filippov, A., Kozlovsky, B., Kozlovskaya, I., Russo, P., Smart, C., and Fry, W. 2001. Genotypic analysis of Russian isolates of Phytophthora infestans from the Moscow region, Siberia and Far East. Journal of Phytopathology 149: 605-611.
Fry, W.E. and Goodwin, S.B., 1997. Resurgence of the Irish Potato Famine Fungus. Bioscience, 47: 363-371.
Goodwin, S. B., Smart, C. D., Sandrock, R. W., Deahl, K. L., Punja, Z. K. and Fry, W. E. 1998. Genetic change within populations of Phytophthora infestans in the United States and Canada during 1994 to 1996: Role of migration and recombination. Phytopathology 88: (939-949).
Grünwald, N. J., Flier, W. G., Sturbaum, A. K., Garay-Serrano, E., van den Bosch, T. B. M., Smart, C. D., Matuszak, J. M., Lozoya-Saldaña, H., Turkensteen, L. J. and Fry, W. E. 2001. Population structure of Phytophthora infestans in the Toluca Valley region of Central Mexico. Phytopathology 91: 882-890.
Reis, A., C. D. Smart, W. E. Fry, L. A. Maffia and E. S. G. Mizubuti (2003). "Characterization of isolates of Phytophthora infestans from southern and southeastern brazil from 1998-2000." Plant Disease 87: 896-900.
Migrations of Phytophthora infestans during the latter part of the 20th century
Antheridium and oogonium of P. infestans