ISOZYME VARIATION AND GERMPLASM RELATIONSHIPS IN THE ERAGROSTIS-CURVULA COMPLEX

Eragrostis curvula germplasm includes a diversity of forms whose biosy stematic relationships remain obscure. Because the E. curvula complex reproduces primarily by apomixis, morphological characters may be insu fficient to assess biological affinities among them. Seed isozyme anal ysis of 52 strains, including several different morphological types, a nd 24 hybrids provided useful descriptors. Distinct bands were found f or each of those types and were used as isozyme markers. Cluster analy sis revealed similarities within and among types in agreement with mor phological characters. Principal coordinate analysis showed a distribu tion of variability within the complex and supported the existence of genetic groups based on ploidy level, mode of reproduction and isozyme bands. Results also provided new information about the genetic relati onships of certain materials whose morphological characteristics were intermediate and allowed detection of misclassified strains. (C) 1997 Elsevier Science Ltd.