Floral Morphology and Genotypic Evaluation of American Marigold Parental Lines using RAPD Technique

Abstract

Marigold (Tagetes erecta L.) is an ornamental plant in Asteraceae (Compositae) family. Marigold flowers are popularly used as an ornamental plant, cut flowers for making lei, and spiritual flowers. It can be grown all over the regions. However, information on research and improvement of marigolds in Thailand is limited. Twelve parental lines were studied using the morphological description of Supa (1991). The result showed that these parental lines could be divided according to 2 flower morphological characters 1) flower color: yellow and golden yellow and 2) flower form: fully double flower, single flower, and apetalous). RAPD banding pattern was employed to evaluate the genetic relationships of these parental lines. Twenty primers were used, and only six primers could yield polymorphic bands. Similarity coefficients were calculated, and a dendrogram was constructed by UPGMA using NTSYS (version 2.2). The results showed that the similarity index of 3 primer, OPA - 02, OPD - 11, and OPD - 19 was 0.41 - 1.00, which could differentiate sterile female parents from male parents. Dendrogram of 6 primer products, OPA - 02, OPA - 04, OPD - 05, OPD - 07, OPD - 011, and OPD - 19, showed similarity coefficient ranging from 0.42 to 0.82, which could distinguish these parental lines into three groups according to flower form; fully double flower, single flower, and apetalous as found in the morphological study.