Understanding Orobanche and Phelipanche–host plant interactions and developing resistance

Abstract

Summary Orobanche and Phelipanche spp. (broomrapes) are parasitic plants that can be responsible for devastating losses in several important crops. The development of resistant cultivars is one of the key strategies in the fight against this pest. However, the nature of resistance is complex and the basis of the interaction between the host and the parasite is still largely unknown. Despite the progress achieved during the last century through breeding programmes, sources of resistance are often scarce (e.g. the legumes). The resistance that is available is often not durable, with field resistance being overcome by new races of the parasite (e.g. sunflower). This review summarises efforts made to improve the resistance of crop hosts for broomrapes through classical breeding programmes and looks forward to the integration of new knowledge generated from molecular and morphological studies. Emphasis is given to the need for a multidisciplinary approach to achieve success, ranging from improved field phenotyping to genetic and biotechnological studies. All components are necessary to understand this particular and characteristic interaction: a plant parasitising another plant.

Progress in research on breeding for resistance to sunflower broomrape

“…Quantitative trait loci (QTL) analyses showed that, in addition to the major gene Or 5 , resistance to race E has also a quantitative component determined by four QTLs with minor effects, in some cases non-race specific and mainly associated with the number of broomrape stalks per plant (Pérez-Vich et al, 2004). The existence of this polygenic component in race E resistance is supported by histological observations and gene expression studies that demonstrated that several mechanisms such as reduced stimulation of broomrape seed germination or rapid necrosis at early stages of parasite development are involved in resistance to this broomrape race (Labrouse et al, 2001;Pérez de Luque et al, 2009). In contrast to race E, molecular studies concluded that recessive resistance to race F in sunflower line P-96 was determined by six QTL, some of which were non-race specific and stable over environments (Pérez-Vich et al, 2004).…”

Legume breeding for broomrape resistance

“…Only moderate to low levels of incomplete resistance of complex inheritance against O. crenata have been identified in legumes Pérez-de-Luque et al 2009;Sillero et al 2010) making selection more difficult and slowing down the breeding process. Resistance to broomrape appears to have multiple components and to be based on a chain of escape and resistance mechanisms that either act alone or in combination and at different stages of the infection process (Rubiales 2003).…”

“…The integration of information obtained from QTL analysis with gene and protein expression analysis currently performed in pea or in the model plant M. truncatula in response to O. crenata infection (Castillejo et al 2004(Castillejo et al , 2009(Castillejo et al , 2012Die et al 2007;Dita et al 2009) can shortcut conventional breeding or marker-assisted selection in identifying candidate genes. Also, sequence information obtained from different parasitic plant species (Westwood et al 2012) will help in understanding parasite virulence and host resistance mechanisms.…”

Disease resistance in pea (Pisum sativum L.) types for autumn sowings in Mediterranean environments - a review

“…Only incomplete resistance to O. crenata was found in other grain legumes like faba bean that has been successfully accumulated by breeding, allowing the release of resistant cultivars (Pérez-De-Luque et al 2009). A similar effort in pea breeding for broomrape resistance has been started only recently.…”