Impact of agrochemicals on Peronospora sparsa and phenolic profiles in three Rubus arcticus cultivars.
The main arctic bramble ( Rubus arcticus) cultivars are susceptible to downy mildew ( Peronospora sparsa), which seriously threatens the cultivation. The efficiency of Aliette, Euparen M, phosphite-containing Phosfik, Phostrol, Farm-Fos-44, and Kaliumfosfiet, as well as Bion was evaluated in the greenhouse. Fewer symptoms and less Peronospora DNA were found in plants treated with Euparen M and Bion, whereas Aliette, Phosfik, and Phostrol gave moderate protection. Three arctic bramble cultivars showed varying susceptibility to P. sparsa. An inexpensive and fast in vitro plate test gave results parallel with those obtained in the greenhouse. Quantitative differences were found in the phenolic profiles of the leaves of different cultivars and in different treatments. Several phenolic compounds were tentatively identified in arctic bramble for the first time, for example, monomeric and oligomeric ellagitannins and galloylglucoses. Negative correlation was found between the amount of P. sparsa DNA and flavonol glycosides and some ellagitannins in the leaves 8 days after inoculation, suggesting a possible role for these phenolics in the defense.
Hukkanen
Anne
A
Department of Biosciences, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland. Anne.Hukkanen@uku.fi
Kostamo
Katri
K
Kärenlampi
Sirpa
S
Kokko
Harri
H
D016573:Agrochemicals / Q000494:pharmacology*; D005838:Genotype; D044742:Peronospora / Q000187:drug effects*; D010575:Pesticides / Q000494:pharmacology; D010636:Phenols / Q000032:analysis*; D010935:Plant Diseases / Q000235:genetics; D018515:Plant Leaves / Q000737:chemistry; D027824:Rosaceae / Q000737:chemistry* / Q000187:drug effects* / Q000235:genetics
D016573:Agrochemicals; D010575:Pesticides; D010636:Phenols