Abstract
Striga spp., devastating root parasitic weeds, attack monocot crops including sorghum, millet and maize in semi-arid tropics. Their seeds require germination stimulants (mainly strigolactone, SL) released from host roots to germinate. In the present study, characterization of SLs in the root exudates from maize plants including the Striga susceptible cultivar Pioneer 3253 and tolerant cultivars KST94 and WH502, grown hydroponically was conducted by comparing retention times of germination stimulants on reversed phase HPLC with those of synthetic standards and by using LC/MS/MS. The susceptible cultivar mainly exuded larger amounts of 5-deoxystrigol and the tolerant cultivars exuded mainly strigol, sorgomol and orobanchol. 5-Deoxystrigol is more stable than hydroxy-SLs like strigol and thus susceptible cultivars might induce more germination of Striga seeds in the fields.
