Variability of decorative traits, response to the Aphis fabae attack and RAPD diversity in different genotypes of Calendula

Abstract

In order to identify cultivars with special decorative value and potential genitors for breeding process, 45 genotypes of Calendula genera were analyzed, belonging to six species: C. officinalis, C. alata, C. arvensis, C. stellata, C. suffruticosa and C. tripterocarpa. The average height of plants varied strongly, from 22.0 cm (C. officinalis cv. Rozovyi Sjurpriz) cm to 84.1 cm (C. tripterocarpa Rupr.). The lowest number of branches per plant was recorded on C. arvensis F. (4.6) and the largest one on C. officinalis LDA (16.4). The average number of flowers per plant ranged from 98.0 (C. suffruticosa Valh.) to 2.0 (C. officinalis UK). From among all genotypes, aphids (Aphis fabae) have attacked 19 (42.2%), and the results showed that AD% (Attack Degree) depend significantly on genotypes. RAPD analysis and phylogenetic dendrogram illustrated the relationship between genotypes and DNA polymorphism exists between the six species. Were found not only close phylogenetic links among cultivars apart of the same specie, but also between different species. C. officinalis A., C. alata UK and C. suffruticosa formed a subgroup similar to the molecular level, but also confirming some phenotypic similarities, these species having the smallest number of petals in the corolla and the highest sensitivity to Aphis fabae attack. The large variability identified in Calendula genotypes allows the selection of potential genitors for new breeding works, with appropriate decorative characteristics and resistance to aphids attack. RAPD analyses and phenotypic study allows hypothesis regarding the success of intra- and inter-specific hybridization, thus facilitating Calendula breeding processes.