Striga spp

Allelopathy found hopeful utilization in plant protection against parasite weeds. The main world parasitic species are the witchweeds (Striga spp.), broomrapes (Orobanche spp.), and eventually dodder (Cuscuta spp.). Witchweeds and broom-rapes attack many economically important crops especially throughout the semi-arid regions. Early detection of parasitic weed infestation and protection is difficult because of the growth habit of a root parasite and huge production of dust-like seeds viable up to 20 years (Kebreab and Murdoch 1999). 

The denomination strigolactones comprises a relatively low number of structurally related compounds isolated from host and nonhost plants that induces the germination of Striga spp. and Orobanche spp. All of them share as common features a tricyclic degraded sesquiterpene skeleton (rings A, B, and C, Fig. 6.1) and a lactone-enol-y-lactone moiety (rings C and D, Fig. 6.1). 

Ethylene is a potent inductor of Striga spp. germination.26 It has been hypothesized as a possible mechanism for parasitic seed germination that attachment of the inductor to the receptor s site triggers a cascade of biosynthetic reactions leading to the synthesis of the enzymes necessary for ethylene production.12... 

Parasitic weeds such as witchweeds (Striga spp.) and broomrapes (Orobanche spp.) are known to cause severe yield losses in grains and legumes in Africa, Asia and the USA. The seeds of such weeds remain... 

Matusova, R. et ah, The strigolactone germination stimulants of the plant-parasitic Striga and Orobanche spp. are derived from the carotenoid pathway, Plant Physiol. 139, 920, 2005. 

---