Distribution and genetic diversity of Orobanche in Tunisia

Abstract

Abstract Orobanche foetida is an obligate parasite which infects the roots of host legumes range in Tunisia and in particular the faba bean causing severe damage to this crop. The use of molecular markers may be a suitable method for the identi cation of pathogenic groups in parasite populations. Genetic diversity of O. foetida specimens parasitizing several host legumes particularly faba bean was initiated in our lab using random ampli ed fragment length polymorphism DNA (RAPD). The parameters of variability calculated, detected an average value of 10.71 alleles per locus and the dendrogram obtained using the Dice coef cient allowed us to distinguish unambiguously all the specimens of O. foetida studied. Signi cant genetic differentiation among O. foetida populations was detected; diversity was attributed to differences among individuals within populations and among populations. The need of availability of good markers which could give a higher degree of resolution for discriminating closely related germplasm, could be useful to better understand the structure of populations and to well identify pathogenic groups. Better knowledge of the evolution of this species is essential to determine the risks of the appearance of more virulent specimens or of its introduction into countries where it has not yet been observed on faba bean. A planned collaboration with researchers from the Iwate biotechnology Researcher Center is on-going, to study the host interaction and gene expression associated with the response to parasitism and to identify key genes associated with resistance.