Transformation efficiency in Chrysanthemum from various sources of explants

Abstract

Nowadays, Chrysanthemum is one of the most popular ornamental plants. However their production is constrained by problems with pests and diseases, mainly white rust disease (Puccinia horiana P. Henn). One potential alternative is the development of plants through genetic engineering, namely disease resistant transgenic plants. Problem that often occurs in the process is the inhibition of regeneration of calli from the transformation that makes it difficult for researchers to carry out DNA testing from leaves. Calli regeneration is regulated by several factors, such as the use of explant sources and media composition. This study aims to find best explant sources for transformation results into shoots, for DNA analysis. The study was carried out at the level of transformation with three types of explants namely leaves, lateral shoot buds, and internodes. Genetic transformation was carried out by two-stage co-cultivation method using Agrobacterium tumefaciens strain EHA105 which contained pEKB-WD binary vector T-DNA construct. Results showed that the most appropriate genetic transformation of explants originating from internodes was 69.33%, but the explants had the lowest regeneration efficiency (1,92%). The highest regeneration efficiency was obtained in explants originating from lateral shoot buds, which amounted to 77.78% with transformation efficiency 54,00%. Both lowest efficiencies were found in leaves (27,31%) for transformation efficiency and regeneration efficiency of 6,45%.