Taxonomic studies in wall barley (Hordeum murinum sensu lato) and sea barley (Hordeum marinum sensu lato). 2. Multivariate morphometrics

Abstract

The demarcation of the Old World species in Hordeum L. section Hordeastrum Doell. has been the subject of considerable controversy. The present paper reports the results of a morphometric analysis of the wall and sea barleys (H. murinum L., H. marinum Huds., and their allies). A sample of 227 accessions was scored for 39 characters, and the resulting data matrix was divided into three groups on the basis of lodicules and cpiblast characters. These three groups were then subjected to several aspects of discriminant analysis (stepwise discriminant analysis, linear discriminant analysis, canonical analysis of discriminance, and nearest neighbor discriminant analysis) both on untransformed and log-transformed data. The results indicate that the wall and sea barleys consist of five distinct groups worthy of morphological specific rank. These correspond to H. marinum sensu stricto, H. geniculatum All., H. glaucum Steudel. H. murinum sensu stricto, and H. leporinum Link. Ranges for 37 characters within these five taxa are presented. A key to the five species and one hybrid (reported in the first paper of this series) is supplied. Our conclusions are discussed in the context of various taxonomic treatments of the group.