engleski

Genetic variability of Orobanche foetida Poir. populations attacking cultivated and wild legumes

By far the most economically damaging parasitic plant species on legumes is Orobanche crenata Forks., Orobanchaceae, but some other broomrapes such as O. minor Sm. and O. aegyptiaca Pers. can also be of importance in certain areas. O. foetida Poir. is widely distributed in the Western Mediterranean area and it typically parasitizes wild plants. Only recently, it has been described as an agricultural problem in legume crops in Tunisia. The O. foetida populations growing on crops were sampled from chickpea (Cicer arietinum L.) and faba bean (Vicia faba L.) fields on the same farm in Beja, Tunisia. O. foetida populations parasitizing wild hosts were collected in Spain (Córdoba and Granada) and Morocco. The pattern of genetic variation was analysed by RAPD markers. An UPGMA cluster analysis based on Dice's distance matrix was performed. The analysis of molecular variance (AMOVA) was used to partition the total phenotypic variance into within populations, among populations within groups, and between groups (populations on crops vs. populations on wild species). The resulting dendrogram showed a clear separation of all the populations sampled. A two-way nested AMOVA showed that the most of the phenotypic diversity was attributable to differences among individuals within populations (46.16 %). The remaining phenotypic diversity was distributed among populations (34.08 %) and between groups (19.77 %). Fi-values were significant among populations within both groups but not significant between groups of populations growing on crops and wild species. In spite of a substantial internal variation among individuals within O. foetida populations growing on crops (69.80 %), there was a significant divergence among the two hosts considered (30.20 % ; fi = 0.302 ; p < 0.001), confirming a clear host-differentiation between O. foetida populations infecting chickpea and faba bean.

Orobanche foetida; population genetics; host-differentiation; RAPDs

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