Aesculus pavia foliar saponins: defensive role against the leafminer Cameraria ohridella.
BACKGROUND
Recently, the leafminer Cameraria ohridella Deschka & Dimic has caused heavy damage to the white-flowering horse chestnut in Europe. Among the Aesculus genus, A. pavia L. HBT genotype, characterised by red flowers, showed an atypical resistance towards this pest. Its leaves, shaken in water, originated a dense foam, indicating the presence of saponins, unlike the common horse chestnut tree. The aim was to isolate and identify these leaf saponins and test their possible defensive role against C. ohridella.


RESULTS
Spectroscopic analyses showed that A. pavia HBT genotype leaves contained a mixture of saponins, four of which were based on the same structure as commercial escin saponins, the typical saponin mixture produced by A. hippocastanum and accumulated only within bark and fruit tissues. The mixture showed a repellent effect on C. ohridella moth. The number of mines detected on the leaves of A. hippocastanum plants treated with A. pavia HBT saponins through watering and stem brushing was significantly lower than the control, and in many cases no mines were ever observed.


CONCLUSIONS
The results showed that the exogenous saponins were translocated from roots/stem to the leaf tissues, and their accumulation seemed to ensure an appreciable degree of protection against the leafminer.
Ferracini
Chiara
C
DIVAPRA-Entomologia e Zoologia Applicate all'Ambiente Carlo Vidano, Università degli Studi di Torino, Grugliasco, Italy. chiara.ferracini@unito.it
Curir
Paolo
P
Dolci
Marcello
M
Lanzotti
Virginia
V
Alma
Alberto
A
D031319:Aesculus / Q000033:anatomy & histology / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001688:Biological Products / Q000032:analysis / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D005838:Genotype; D007814:Larva / Q000187:drug effects; D009036:Moths / Q000187:drug effects*; D010641:Phenotype; D018515:Plant Leaves / Q000737:chemistry*; D012503:Saponins / Q000032:analysis / Q000494:pharmacology*
D001688:Biological Products; D012503:Saponins