Showing papers on "Dendrogram published in 1987"

Application of Cluster Analysis for Establishment of Genetic Similarity in Gene‐For‐Gene Host‐Parasite Relationships

Abstract: Genetic similarity and/or dissimilarity among virulence phenotypes of phytopathogenic organisms and generally in gene-for-gene relationships can be exactly expressed by cluster analysis. The present paper deals with the application of a definite hierarchical agglomerative clustering method based on μ-connected clusters as a means for describing genetic structure of virulence in a set of 48 physiological races (isolates) of Bremia lactucae (lettuce downy mildew). A dendrogram and a minimums, panning tree were used to distinguish between virulence phenotypes of B. lactucae. Further application of the methods of numerical taxonomy to phytopathology is briefly discussed.

Parsimonious trees

Abstract: Dendrograms based onn objects can contain as many asn − 1 levels (internal nodes) and prove difficult to interpret. Two methods are described for transforming a dendrogram into a more readily interpretable parsimonious tree. These involve limiting either (i) the number of different values taken by the heights of the internal nodes, or (ii) the number of internal nodes. An illustrative example is presented.

Isozyme characterization of ascosphaerales associated with bees. iv. analyses1

Abstract: A dendrogram was constructed that utilized indices of genetic distance for all isolates tested in an isozyme characterization of Ascosphaerales. The Ascosphaerales clustered into three groups: (1) A. proliperda and A. atra, (2) mating types of A. apis, and (3) A. asterophora and A. major. Ascosphaera aggregata and Bettsia alvei did not cluster consistently with other isolates.