A method for estimation of tree's condition on activity of defence response in phloem was checked in Pinus sylvestris L. stands located near Krasnoyarsk (Siberia, Russia). The length of necrosis caused by inoculation of phloem of living tree by Ceratocystis laricicola Redf. et Minter was used as the parameter being measured. The field experiments were carried out in two even-aged (about 60 years) pine stands that were approximately equal on structure, productivity, density and recreation loading, but differentiated on degree of industrial pollution. The two permanent sample plots (SP) were founded in the severely polluted stand. The other two SP were placed in the unpolluted pine forest. The amount of pine trees within each SP varied from 200 to 250. From 22 up to 37 pine-trees selected randomly within every SP were inoculated with C. laricicola mycelium (test 1) and its extract (test 2). One inoculation hole per one tree (diameter 7 mm) was made in stem at a height of 1.3 m. Application of the both agents caused necrosis in phloem around the place of inoculation. In the case of fungal inoculation (test 1), the average length of necrosis in the unpolluted forest exceeded significantly the same parameter in the polluted stand: 51.7-79.4mm and 39.4-41.3mm, correspondingly. The action of the fungal metabolites caused the opposite results: in the unpolluted stand the average size of necroses was smaller in comparison with this parameter in the polluted stands 44.5-15.3 mm and 57.9-61.8 mm. The reasons of this difference are discussed. The both agents (C. laricicola mycelium and its extract) were suitable to reveal the difference of tree's condition in polluted and unpolluted pine stands. The application of fungal extract is more preferable in comparison with fungal mycelium because of smaller variability of necrosis size. Besides, the application of extract allows controlling inoculum dose and excludes the dangerous of spreading infection in forests.
|ジャーナル||Journal of the Faculty of Agriculture, Kyushu University|
|出版ステータス||出版済み - 10 1 2008|
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