Relationship between molecular markers and morphological traits in a cassava collection

In order to study the relationship between the molecular and morphological characterizations in a cassaya (Manihot esculenta Crantz) germplasm collection at the CENIAP-INIA, Marcay, Venezuela, 19 Morphological traits were evaluated and compared with the non-hierarchic structure generated by the RAPD primers: OPA-04 and 07, OPB-07, OPK-03, 05 and 15, OPM-04, 14, 18 and 20, for 65 entries of the collection. The relationships between the molecular markers and morphological trait patterns were studied using the error rate estimate for groups from the function linear discriminate, simple correspondence analysis and Shannon diversity index. The cassava collection was distributed among four main groups in the molecular and morphological characterization, respectively. The linear discriminate analysis of morphologic traits showed that 60.12% of the collection waws classified into molecular groups. The molecular markers showed higher genetic diversify than the morphological traits. These results emphasize the importance of joint treatment of morphological traits and molecular markers because they generate information that can be considered complementary, since a unique pattern of association between accessions does not originate and shows that high phenotypic similarity need not be genetically similar as different gene pools can show similar phenotypes.