Populations of Phytophthora infestans present on potato in the Cundinamarca and Boyacá plateau in 1996 are monomorphic for glucose-6-phosphate isomerase
Potato late blight, a disease caused by the Oomycete Phytophthora infestans, is responsible in great proportion for severe decrements in potato production in the Cundinamarca and Boyacá plateaus. Until now, late blight control has been done mainly with fungicides. The widened genetic variability in populations of this organism for a number of traits, including sensitivity to commercially available fungicides, observed in a world-wide perspective, has shown the need to research the genetic structure of local populations. This study was launched to characterize the populations of P. infestans in Cundinamarca and Boyacá through the polymorphism of glucose-6-phosfate isomerase (GPI). The results pointed at a clonal nature of these populations. All the local isolates were homozygous monomorphic for GPI, with genotype 100/100. Isolate Ro showed genotype 86/100 that corresponds to lineage US-1. Isolate MT2 showed genotype 84/100. These iso lates correspond to heterozygous populations that may have resulted from sexual reproduction. Isolate HIN had genotype 100/100, coinciding with local isolates. This isolate belongs to mating type A1 and corresponds to lineage US-6. This lineage represents one of the earliest migrations from Mexico to the United States, Europe and the rest of the world. Prior to the migrations of mating type A2. Results indicate that local populations are not too diverse, and suggest a clonal orrqtn. These results agree with the evaluation of this same population as regards sensitivity to metalaxil and mating type (Gonzalez, 1997). Thus, it appears as if local populations of P. infestans in Cundinamarca and Boyaca on the whole were clonal, and made up of one genotype. From thishomogeneity in the GPI alleles, one may conclude the prevalence of asexual reproduction, which restricts greatly genetic variation. Different results such as the appearance of novel genotypes would have supported the alternative view of migrations from other populations or sexual recombination involving mating types A1 and A2.
| Main Authors: | , |
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| Format: | Digital revista |
| Language: | spa |
| Published: |
Universidad Nacional de Colombia - Sede Bogotá - Facultad de Ciencias Agrarias
1998
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| Online Access: | https://revistas.unal.edu.co/index.php/agrocol/article/view/21489 |
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