sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDU Faculty of Forestry Journal
Serial: A, Number: Special Issue, Year: 2009, ISSN: 1302-7085, Page: 48-56
SUSCEPTIBILITY OF DIFFERENT CONIFEROUS SEEDLINGS
INOCULATED WITH Diplodia pinea
H. Tuğba Doğmuş-Lehtijärvi 1* , Asko Lehtijärvi 1 , Gürsel Karaca 2 ,
A. Gülden Aday 1 , Funda Oskay 1
1 Süleyman Demirel University, Faculty of Forestry, Dept. of Botany, Isparta-Turkey
2 Süleyman Demirel University, Faculty of Agriculture, Dept. of Plant Protection, Isparta-Turkey
ABSTRACT
* tugba@orman.sdu.edu.tr
In this study, virulence of 5 Diplodia pinea isolates on Pinus nigra, Pinus brutia, Pinus
sylvestris, Cedrus libani, Abies nordmanniana ssp. bornmülleriana and Juniperus excelsa
seedlings was investigated. Needle fascicles on terminal and three lateral shoots of each
seedling were removed to create small wounds. Agar plugs with D. pinea mycelia were
placed in the wounds and secured in position with laboratory film. Five seedlings were used
for each species-isolate combination and a randomized complete block design was used in
the trial. Nine weeks later dead shoots, lesion length and fungal growth were recorded.
Dead shoots occurred in almost all isolate–host combinations: the only exceptions were two
isolates on J. excelsa. Within host variation in dead shoot rates among the isolates was low.
However, there was high variation in the mean dead shoot rate among the hosts, with the
highest rate (98.0%) on C. libani, and the lowest (4.0%) on J. excelsa. On C. libani all
isolates caused remarkable lesion, while on the other host species some of the isolates
caused lesion. The average lengths of lesion were 15.72 mm on C. libani, 8.12 mm on P.
nigra, 2.4 on P. sylvestris, 1.2 on P. brutia and 0.08 mm on A. nordmanniana ssp.
bornmülleriana and J. excelsa. Similarly, average linear extension of D. pinea in the shoot
tissues was high on C. libani and Pinus spp. and low on J. excelsa. The results indicate high
virulence of D. pinea on C. libani and P. nigra.
Keywords: Pathogenicity, Pinus nigra, Pinus brutia, Pinus sylvestris, Cedrus libani,
Abies nordmanniana ssp. bornmülleriana, Juniperus excelsa
1- INTRODUCTION
Diplodia pinea (Desm.) Kickx. (=Sphaeropsis sapinea (Fr.) Dyko Sutton) has
a worldwide distribution and causes the disease known by the common name of
Diplodia tip blight of pine (Stanosz et al., 1996). The fungus can affect the trees
from early to older ages causing shoot blight, twig blight, dead top, sap stain, root
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