identifying host plants of hyobanche l. (orobanchaceae) by dna sequencing of host root tissue
Post on 12-Jan-2016
24 Views
Preview:
DESCRIPTION
TRANSCRIPT
Identifying host plants of Hyobanche L.
(Orobanchaceae) by DNA sequencing of
host root tissue
Andrea D. Wolfe and Nidia Arguedas
The Ohio State University
Background on Hyobanche
• Small genus of holoparasitic plants endemic to southern Africa– Eight species described as of 1996
• One not seen in herbarium collections; three to be submerged into one spp
– Another seven to be described
• Host plants noted on herbarium sheets– Asteraceae, Ericaceae, Euphorbiaceae, Poaceae,
Restionaceae, Sterculiaceae, Thymelaeaceae
sp. nov. sp. interm.
sanguinea atropurpurea.
Background on Hyobanche
• Small genus of holoparasitic plants endemic to southern Africa– Eight species described as of 1996
• One not seen in herbarium collections; three to be submerged into one spp
– Another seven to be described
• Host plants noted on herbarium sheets– Asteraceae, Ericaceae, Euphorbiaceae, Poaceae,
Restionaceae, Sterculiaceae, Thymelaeaceae
Usually based on proximity. . .
which may or may not have anything to do with the actual host plant!
Rhizomes of Hyobanche may be several meters long, and host roots are attached along the length of the rhizome on specialized haustoria from leaf bracts.
Haustorial connections are generally fragile, which makes tracing the host-parasite attachment difficult.
Fynbos
Coastal habitats
Karoo
High Veld
Methods
• Excavate rhizome system of Hyobanche
• Collect roots attached via haustorial connections
• Collect leaf tissue of plants in vicinity
• Sequence ITS and rbcL from roots and leaves– Matching sequence infers host of Hyobanche
Conclusions
• DNA “fingerprinting” approach works well for identifying hosts of Hyobanche– Positive identifications made for every
population sampled
• Host range of coastal populations primarily in Asteraceae– Also found on Passerina and Bromus
Acknowledgments
Field Assistance: Brad Ripley, Tony Dold, Beyers Cronje
Funding: National Science Foundation
top related