Wood Anatomical Characteristics of Domestic Red Pine (Pinus densiflora) Infested by Pine wood Nematode (Bursaphelenchus xylophilus)

Abstract

The pine wilt disease is one of the most serious forest diseases that kill the pine trees, and the study on the invasion and movement of the pine wood nematode within the tree is very important for understanding the inhabitation of pine wood nematode. In this relation, the microscopic observation was carried out to study the place of inhabitation and movement of pine wood nematode within the infested wood. In result, the rays were mainly infested by pine wood nematode and showed dark discoloration due to their necrosis in cross, radial and tangential surface. Also, the intensive damage was found in the resin canals. On the other hand, some traumatic resin canals in tangential band were identified in the sapwood near the cambium.In the ray, the pine wood nematode occurred more commonly in the ray parenchyma cell and fusiform ray with horizontal resin canal than in the ray tracheid and uniseriate ray without horizontal resin canal, respectively. The pine wood nematode was thought to move from ray to tracheid through the large natural opening, window-like pit, in the cross-field, neither through the small natural opening, bordered pit, in the tracheid nor through the tracheid wall by creating a bore hole.

Transcriptomic Profiling Reveals Differentially Expressed Genes Associated with Pine Wood Nematode Resistance in Masson Pine (Pinus massoniana Lamb.)

“…The anatomical and biochemical changes of pine trees with PWN infection have been characterized over the past 40 years 13 . As for the pathogenic mechanism of pine wilt disease, several hypotheses have been put forward, such as cavitation formed by terpenoids blocking water transport in xylem tracheids 14 , 15 , phytotoxins produced by PWN-associated bacteria causing the death of pines 16 , 17 , the cellulose and pectin secreted by PWN degrading the cell walls of pines and causing their death 18 , etc.…”

Life in the woods: Taphonomic evolution of a diverse saproxylic community within fossil woods from Upper Cretaceous submarine mass flow deposits (Mzamba Formation, southeast Africa)

“…Fig. 29A, B) is typical of the pine wilting disease (Mamiya, 2006;Ahn et al, 2011), a pathology induced in extant trees by Parasitaphelenchidae 'eelworm' infestation. Penetration of the wood by such nematodes is commonly facilitated by saproxylic coleopterans, especially Cerambycidae (Nickle, 1970).…”