Analysis of diversity and relationships among Gladiolus cultivars using morphological and RAPD markers

Abstract

A study was conducted during 2003–05 to identify and characterize 54 Gladiolus cultivars using morphological traits and RAPDs and to estimate the genetic relationships between the selected genotypes. Nine morphological traits and 225 random amplified polymorphic DNA (RAPD) markers amplified with 25 arbitrary primers were employed to discriminate between the cultivars and to evaluate the relatedness between them. A total of 225 RAPD bands (250–3000 bp) were obtained of which 211 (93.78%) were polymorphic. Number of bands generated per primer ranged from 4 to 14 with an average of 9 bands. For morphological data, Euclidean distances were calculated and an unweighed pair-group method using an arithmetic average was used to construct a dendrogram. In addition, principal component analysis was carried out based on RAPD data. In both the cluster analyses, cultivar ‘Pusa Lohit’ branched out from the dendrograms, confirming that it is quite different from all other genotypes. Furthermore, cultivar pairs ‘Ripples’ and ‘Anglia’, ‘Friendship’ and ‘Yellow Jame’, ‘Creamy Green’ and ‘Morello’, ‘Pusa Suhagin’ and ‘Pusa Archana’, ‘The Barton’ and ‘Christian Jane’, ‘Plumtart’ and ‘Chantiler’ and ‘Peter Pears’ and ‘Picardy’ were very close in both the dendrograms indicating that they are quite similar to each other and this result was also supported by PCA analysis. However, incongruence existed between these cluster analyses, and the relationships between some cultivars require further investigation.