First report of Lecanosticta acicola in Turkey and new host records
In March 2017, severe blight symptoms resembling those caused by Lecanosticta acicola (EPPO A2 List) were observed in the Atatürk Arboretum in Istanbul, Turkey. The disease was observed on needles of Pinus nigra subsp. pallasiana (Anatolian black pine – including two endemic varieties of this subspecies: fastigiata and pallasiana), as well as on Pinus sylvestris (Scots pine). Following these initial observations, a survey was conducted in 2017/2018 on a total of 37 trees from 28 taxa (4 Cedrus and 24 Pinus) in the arboretum. The presence of the fungus in samples of symptomatic needles was confirmed by isolation followed by molecular identification (sequencing of the ITS region). L. acicola was isolated from symptomatic needles of 10 trees belonging to the following 7 taxa: Cedrus libani, Pinus sylvestris, P. nigra subsp. nigra, P. nigra subsp. laricio, P. nigra subsp. pallasiana, P. nigra subsp. pallasiana var. fastigiata and P. nigra subsp. pallasiana var. pallasiana f. şeneriana. Disease severity, assessed by estimating the percentage of symptomatic crown volume, ranged between 10% and 100%. Infection severity was highest on the endemic varieties of P. nigra subsp. pallasiana (80%-100%) and lowest on C. libani. This is the first time that L. acicola is reported from Turkey, as well as on a non-pine species Cedrus libani and on two varieties of P. nigra subsp. pallasiana under natural conditions. The authors also noted that the introduction of L. acicola may accelerate the disappearance of already endangered Turkish Pinus taxa (P. nigra subsp. pallasiana var. fastigiata and var. pallasiana f. şeneriana).
The situation of Lecanosticta acicola in Turkey can be described as follows: Present, few occurrences (first observed in the Atatürk Arboretum, Istanbul in 2017).
Sources
Oskay F, Laas M, Mullett M, Lehtijärvi A, Doğmuş-Lehtijärvi HT, Woodward S, Drenkhan R (2020) First report of Lecanosticta acicola on pine and non-pine hosts in Turkey. Forest Pathology 50, e12654. https://doi.org/10.1111/efp.12654