Jack Pine Wood Research Articles

A Species-Specific PCR Assay for Detection of Diplodia pinea and D. scrobiculata in Dead Red and Jack Pines with Collar Rot Symptoms.

A polymerase chain reaction (PCR)-based assay was developed for the specific detection of the fungal pathogens Diplodia pinea and D. scrobiculata from pine host tissues. Variation among mitochondrial small subunit ribosome gene (mt SSU rDNA) sequences of Botryosphaeria species and related anamorphic fungi was exploited to design primer pairs. Forward primer DpF and forward primer DsF, each when used with the nonspecific reverse primer BotR, amplified DNA of D. pinea or D. scrobiculata, respectively. Specificity was confirmed using multiple isolates of each of these two species and those of closely related fungi including Botryosphaeria obtusa. The detection limits for DNA of each pathogen in red and jack pine bark were 50 to 100 pg μl-1 and 1 pg μl-1 in red and jack pine wood. The assay was tested using naturally occurring red and jack pine seedlings and saplings exhibiting symptoms of Diplodia collar rot. Samples from lower stems/root collars of 10 dead trees of each species from each of three sites at each of two locations were tested. Results were positive for D. pinea or D. scrobiculata for the large majorities of symptomatic bark and wood samples from both locations. For positive samples, however, there were effects of location and host species on detection of D. pinea (more frequent on red pine) and D. scrobiculata (more frequent on jack pine) (P < 0.01 in both cases). These results indicate that these new primers are potentially useful for studies in areas or hosts in which both pathogens may be present.

Basic Density of Jack Pine Wood Influenced by Fertilization and Thinning

Basic wood density was measured at eight bole positions within and below the green crown in a jack pine (Pinus banksiana, Lamb.) fertilization and thinning trial near Chapleau, Ontario. Analysis showed a 6% reduction of average density in wood laid down during the first 5 years following treatment. A significant height × fertilizer interaction was noted during the same period indicating that bole density gradients specific to fertilized trees should be used to calculate biomass gains from fertilization if substantial underestimates of response are to be avoided. The portion of the bole where the wood changed most rapidly from low density, juvenile-type to higher density mature-type wood appeared to be just beneath the base of the green crown.

HEART ROT OF JACK PINE IN ONTARIO: II. LABORATORY STUDIES ON THE PATHOGENICITY AND INTERRELATIONSHIPS OF THE PRINCIPAL HEARTWOOD-INHABITING FUNGI

Two Basidiomycetes, Fomes pini (Fr.) Karst. and Peniophora pseudo-pini Weres. &amp; Gibson, and three microfungi (Ascomycetes), Tympanis hypopodia Nyl., Retinocyclus abietis (Crouan) Groves &amp; Wells, and a member of the Coryne sarcoides complex, are the fungi most frequently isolated from the heartwood of living jack pine (Pinus banksiana Lamb.) in the Province of Ontario. Of these, only F. pini is consistently associated with decayed wood. In laboratory tests all five caused significant weight losses in jack pine heartwood samples, and all but the C. sarcoides complex appreciably altered the color of the wood. T. hypopodia was exceedingly antagonistic towards F. pini, both in malt agar culture and when inoculated in advance of F. pini in jack pine wood samples. The activity of P. pseudo-pini in the test samples was reduced slightly by the prior establishment of T. hypopodia and the C. sarcoides complex, but was stimulated somewhat by the presence of R. abietis. The presence of the C. sarcoides complex in jack pine samples resulted in a moderate increase in the activity of F. pini.In some cases competitive interactions among heartwood-inhabiting fungi may partly explain the marked variability in defectiveness frequently observed among individual trees in forest stands.

CONSTITUTION OF A GLUCOMANNAN FROM JACK PINE (PINUS BANKSIANA, LAMB)

A hemicellulose fraction from jack pine wood has been shown to contain D-mannose, D-glucose, and D-galactose in a molar ratio of 49:17:2. The glucomannan was electrophoretically homogeneous and showed a degree of polymerization of 18–21 by three different methods of end group analysis. Methylation and hydrolysis yielded the following O-methyl ethers: 2,3,4,6-tetra-O-methyl-D-glucose (2.8 moles); 2,3,4,6-tetra-O-methyl-D-galactose (1 mole); 2,3,6-tri-O-methyl-D-mannose (52 moles); 2,3,6-tri-O-methyl-D-glucose (15.3 moles); di-O-methyl-D-glucose (1 mole); di-O-methyl-D-galactose (2 moles). Lack of survival of any monosaccharides in the periodate-oxidized glucomannan showed that there was no branching through C2 or C3 of any of the units. Gas–liquid partition chromatography was used to analyze products from methylation and hydrolysis and from periodate oxidation and reduction of the polysaccharides. The results showed that the glucomannan from jack pine was composed of 1 → 4 linked β-D-mannose and β-D-glucose residues with D-galactose residues present as non-reducing terminal units. Branching, if any, must occur through C6 of units making up the polysaccharide. This structure is compared with those of glucomannans found in other soft woods.