Naslov
Unindentified phytophthora : new threat to hybrid poplars in Croatia

Autori
Županić, Miljenko ; Pernek, Milan ; Pilaš, Ivan ; Kajba, Davorin

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings of 4th International Poplar Symposium on Combining Traditional and Novel Approaches in the Genomic Era / - , 2006

Skup
International Poplar Symposium on Combining Traditional and Novel Approaches in the Genomic Era (4 ; 2006)

Mjesto i datum
Nanjing, Kina, 05.06.2006. - 09.06.2006

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
poplar plantations; dieback; pathogen

Sažetak
Aluvial plains around rivers which have, after the hydroameliorative measures on the rivers, lost their natural regime of flooding have become suitable stands for poplar plantations. The longlasting underground water level on this stands is the main factor which has an influence on physical and chemical soil characteristics and soil fertility. In the case of high water levels these stands are flooded and the water stays a long time on the soil surface because natural waterflow back to riverbeds is restricted. All these factors are favorable for Phytophtora dispersal and infection especially in the case of monocultures. The first individual dead trees have been noticed in the poplar plantations in the region of forests near river Drava in 2001. The region has 400 ha of poplar plantations and it is estimated that 5 % have been affected by dieback. The dieback has spread to the neighbouring trees. The tree dieback is particulary present on sites in microdepresions with long-lasting water on the soil surface. The dieback is constantly spreading to other localities which are connected with water chanells from which high water is drained into microdepressions on the poplar plantations. First symptoms of tree dieback were crown damage, chlorosis and leaf shedding. The gum exudation from cracked bark is distinctive in spring and summer. Brown lesions are visible under bark. The disease is spreading in concentric circles to the neighbouring trees and the parts of poplar plantations that are in microdepressions are the most affected. The soil samples with root and root hairs from the base of the affected trees have been taken for isolation of pathogen in laboratory. The isolates have been sent for ITS fingerprinting method. Results of ITS indicate that sequences of this Phytophthora don't match with any of up to this time noted species from gene bank.

Izvorni jezik
Engleski

Znanstvena područja
Šumarstvo

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