Microsatellite isolation and characterization for Colletotrichum spp, causal agent of anthracnose in Andean blackberry.

The genus Colletotrichum, comprised of pathogenic fungi that affect plants grown worldwide, causes the disease known as anthracnose in several fruit and vegetable species. Several studies conducted on plants have shown that the disease is characterized by the presence of one or several species of the fungus attacking the fruit or other organs of the same host. To develop and implement effective control strategies, it is vital to understand the genetic structure of the fungus in agricultural systems, identify associated Colletotrichum species, and define the subpopulations responsible for the disease. Molecular tools were accordingly developed to characterize genotypic populations of Colletotrichum spp, causal agent of anthracnose in commercial crops of Andean blackberry (Rubus glaucus Benth.). A microsatellite-enriched library for Colletotrichum gloeosporioides was developed to identify and characterize microsatellite loci among isolates collected in R. glaucus plantations. Thirty microsatellites were developed and tested in 36 isolates gathered from eight different blackberry-production areas of Colombia. Ten pairs of microsatellites were polymorphic.

Genetic diversity and molecular characterization of several Heliconia species in Colombia.

Researchers have classified the Heliconia genus as a group of highly variable and diverse plants. Species and cultivars are visually differentiated primarily on the basis of the color and size of inflorescence bracts. At taxonomic level, flower type (parabolic, sigmoid, or erect) and size are taken into account. The vast morphological diversity of heliconias at intra-specific, intra-population, and varietal levels in central-west Colombia prompted the present study. We characterized the genetic variability of 67 genotypes of cultivated heliconias belonging to Heliconia caribaea Lamarck, H. bihai (L.) L., H. orthotricha L. Andersson, H. stricta Huber, H. wagneriana Petersen, and H. psittacorum L. f., as well as that of several interspecific hybrids such as H. psittacorum L. f. x H. spathocircinata Aristeguieta and H. caribaea Lamarck x H. bihai (L.) L. We also created an approximation to their phylogenetic analysis. Molecular analysis using amplified fragment length polymorphism (AFLP) markers revealed a total of 170 bands. Two large, well-defined groups resulted: the first grouped cultivars of the very closely related H. caribaea and H. bihai species with those of H. orthotricha and H. psittacorum, and the second grouped H. stricta and H. wagneriana cultivars. The lowest percentage of polymorphism was found in H. psittacorum (17.65%) and the highest was in H. stricta (55.88%). Using AFLP, phylogenetic analysis of the species studied revealed the monophyletic origin of the Heliconiaceae family, and identified the Heliconia subgenus as monophyletic while providing evidence of the polyphyletic origin of several representatives of the Stenochlamys subgenus.