Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrape are in a current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of herbicide use and global warming to a lesser degree. We reviewed relevant facts about the biology and physiology of broomrape weeds and the major feasible control strategies. The points of vulnerability of some underground events, key for their parasitism such as crop-induced germination or haustorial development are reviewed as inhibition targets of the broomrape-crop association. Among the reviewed strategies are those aimed 1) to reduce broomrape seed bank viability, such as fumigation, herbigation, solarization and use of broomrape-specific pathogens; 2) diversion strategies to reduce the broomrape ability to timely detect the host such as those based on promotion of suicidal germination, on introduction of allelochemical interference, or on down-regulating host exudation of germination-inducing factors; 3) strategies to inhibit the capacity of the broomrape seedling to penetrate the crop and connect with the vascular system, such as biotic or abiotic inhibition of broomrape radicle growth, crop resistance to broomrape penetration either natural, genetically engineered or elicited by biotic- or abiotic-resistance-inducing agents and 4) strategies acting once broomrape seedling has bridged its vascular system with that of the host, aimed to impede or to endure the parasitic sink such as those based on the delivery of herbicides via haustoria, use of resistant and tolerant varieties or implementation of cultural practices improving crop competitiveness.

Inactivation of the FCY2 (cytosine permease), FCY1 (cytosine deaminase), and FUR1 (uracil phosphoribosyltransferase) genes in Candida lusitaniae produced two patterns of resistance to flucytosine. Mutant fur1 demonstrated resistance to 5-fluorouracil, whereas mutants fcy1 and fcy2 demonstrated fluconazole resistance in the presence of subinhibitory flucytosine concentrations.

Freshly harvested barley seeds are considered as dormant since they do not germinate at temperatures above 20 °C. This dormancy is broken during dry storage. Molecular regulation of dormancy was investigated using cDNA-AFLP to identify transcripts differentially expressed in dormant and non-dormant embryos. Transcript patterns in embryos from dry dormant and non-dormant seeds and from both seeds imbibed for 5 h at 30 °C, a temperature at which dormancy is expressed, were compared. Thirty-nine Transcript-Derived Fragments (TDF) that were reproducibly differentially expressed among treatments were identified, and 25 of these were cloned and sequenced. Among these, eight transcripts were observed to be differentially expressed during after-ripening, seven of which decline, probably due to post-maturation degradation. HV13B, TDF identified as having homology to fructose-6-phosphate-2-kinase/fructose-2,6-biphosphatase, may have a role in the maintenance of dormancy in barley and probably in other cereals. During the first 5 h of imbibition, there was expression of 24 TDF which was apparently independent of dormancy, revealing putative epigenetic regulation. This was typified by HV44A, a SET domain protein. Seven TDF differentially expressed, and especially HV12D, HV42B, and HV32B, in dormant and non-dormant seeds were potential signalling elements. HV12D had homology with an ARIADNE gene which could be implicated in ABA signalling.

Sur les 82 espèces d'adventices du colza d'hiver ( Brassica napus L.), répertoriées en Poitou-Charentes, 22 sont identifiées comme les plus affines du colza. 50 % des adventices affines sont parasitées aux champs par Orobanche ramosa , jouant le rôle de plantes hôtes. Des co-cultures en serres (adventice/ Orobanche ramosa ) révèlent que des adventices, non parasitées aux champs, peuvent être attaquées par l'orobanche, qui y effectue un cycle plus ou moins complet. Des co-cultures in vitro (adventice/ Orobanche ramosa ) montrent que les exsudats racinaires d'adventices, non parasitées aux champs et en co-culture en serres, peuvent induire la germination des graines d'orobanche, mais sans fixation du parasite. Ces adventices jouent le rôle de faux-hôtes.