In vitro selection for resistance to Fusarium oxysporum f. sp. dianthi and detection of genetic polymorphism via RAPD analysis in carnation

摘要

Embryogenic calli derived from leaf base explants of two carnation cultivars, Lia and White Liberty, were culturedin vitrofor resistance to toxic metabolites produced byFusarium oxysporumf.sp.dianthi, using two selection methods, the double – layer culture and culture filtrate techniques.Results indicatedthat the reduction of callus growth rate was higher with thein vitroselection method using double layer than with thein vitroselection method using culture filtrate. Results also revealed that embryogenic callus percentage, shoot formation and root induction percentages were affected byin vitroselection methods. Regenerated plants from the two tested cultivars were grown to maturity in the greenhouse.Five primers were used to amplify DNA of the two selected carnation cultivars and their sixteen somaclones. A total of 62 amplification products were obtained, out of which 96.15% showed polymorphism. Genetic similarity among the eighteen genotypes ranged from 0.32 to 0.91. Using RAPD technique, the regenerated somaclonal variant lines and their parents were classified into two clusters: The cultivar Lia and its 8 somaclones were grouped in one cluster while the cultivar White Liberty and its somaclones were included in another cluster.The present study indicated that the use of RAPD technique was sensitive and powerful to detect genetic variation at the level of DNA among carnation variants. This might be of particular importance in the future, dealing withinvitroselection forFusarium– resistant lines.