scholarly journals Quantification of Conidia of Diplodia spp. Extracted from Red and Jack Pine Cones

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Isabel A. Munck ◽  
Glen R. Stanosz

Frequency of detection and inoculum production by the conifer shoot blight and canker pathogens Diplodia pinea and D. scrobiculata on cones of red pine (Pinus resinosa) and jack pine (P. banksiana) were studied. Cones were collected from the ground and from canopies of red and jack pine trees in mixed stands at three sites in each of two different locations during two consecutive summers in Wisconsin. Conidia were extracted in water, quantified, germination tested, and the Diplodia species present was determined using molecular methods. At least one pathogen was detected from each tree at each site in both years. Overall, more conidia were extracted from cones from canopies than cones from the ground and from red pine cones than jack pine cones. Both total numbers of conidia extracted and proportions of cones yielding D. pinea or D. scrobiculata varied by location and pine species. Cones from either the ground or canopies can be used for surveys to detect Diplodia spp. at a given site but cones from canopies may be more useful to determine the relative abundance of potentially available inoculum of these pathogens.

2012 ◽  
Vol 42 (10) ◽  
pp. 1819-1826 ◽  
Author(s):  
Oscar Santamaría ◽  
Denise R. Smith ◽  
Glen R. Stanosz

Four endophytes isolated from healthy shoots of adult red pine ( Pinus resinosa Aiton) or jack pine ( Pinus banksiana Lamb.) trees were tested as potential biocontrol agents of the conifer shoot blight and canker pathogens Diplodia pinea (Desmaz.) J. Kickx fil. and Diplodia scrobiculata J. de Wet, B. Slippers & M.J. Wingfield. The effect of the endophytes on the germination of Diplodia species conidia and on the symptom severity caused by these pathogens on P. banksiana seedlings under greenhouse conditions was evaluated. Aggressiveness of each organism also was determined by means of single inoculations on jack pine seedlings. The results indicated that the endophyte Trichoderma atroviride P. Karst. showed a clear antagonism to Diplodia species. The culture filtrate of this fungus was able to reduce spore germination of D. scrobiculata. Furthermore, it was able to inhibit the D. pinea invasion when both organisms were inoculated in the same seedling. The observed reduction in the symptom severity on jack pine seedlings might be due to parasitism and (or) production of inhibitory compounds. Therefore, T. atroviride might deserve further investigations for its use as biocontrol agent against D. pinea.


2005 ◽  
Vol 81 (2) ◽  
pp. 49-55 ◽  
Author(s):  
G. Laflamme ◽  
R. Blais

In the early 1980s, more than 90% of mortality caused by Gremmeniella abietina, European race, was recorded in red pine (Pinus resinosa) plantations 200 km northwest of Montreal, Quebec, Canada. Surrounding jack pines (Pinus banksiana) did not appear to be affected. Consequently, foresters began to plant the affected areas with jack pine seedlings. In 1988, plots of 100 jack pines were established in three of the four selected plantations. As reference, red pine seedlings were planted in 1989 under similar conditions in the fourth plantation. Observations were carried out annually from 1989 to 1992. Mortality of red pine seedlings reached 70% in 1992 while all jack pines on the three experimental sites were free of the disease except for a tip blight, a distinctive feature allowing race identification in the field. The North American race symptoms were present at a very low incidence, but began to increase on site I in 1992. More than 10 years after planting, the jack pine trees still show resistance to the European race of G. abietina while all the red pines died.


1956 ◽  
Vol 34 (1) ◽  
pp. 27-36 ◽  
Author(s):  
L. A. Lyons

The seed capacity of red pine cones varies from about 30 to over 110, depending on the size of the cone and its position in the tree crown, and is determined by the number of ovules that are structurally complete at the time of pollination. These ovules occur in a central "productive" region and constitute less than one-half of the total. The remaining ovules, most: of which are in the proximal part of the cone, never become structurally perfect, and do not contribute to seed production. Abortion of ovules in the productive region usually reduces seed production efficiency to 50–60%, and is accompanied mainly by withering of the nucellus in the first year and failure to produce archegonia early in the second year. The extent of ovule abortion during the first year varies indirectly with cone size, seed capacity, and height in tree.


1987 ◽  
Vol 17 (1) ◽  
pp. 51-57 ◽  
Author(s):  
P. J. Bedker ◽  
M. J. Wingfield ◽  
R. A. Blanchette

Three species of 11-year-old pine trees were inoculated with Bursaphelenchusxylophilus in the field. Four branches in single whorls on red, Scots, and jack pine trees were wounded and inoculated with 10 000 nematodes each or with water extracts from Botrytiscinerea cultures. Prior to field inoculations, the pathogenicity of the nematode isolate was confirmed on seedlings in the greenhouse. Fourteen weeks after inoculation, 27 of 80 and 13 of 52 branches were dead or dying on Scots and jack pine trees, respectively. No symptoms were observed on red pine trees inoculated with B. xylophilus or on any controls. Branch death was attributed to the formation of girdling cankers resulting from inoculation. An average of 9.14, 10.39, and 0.02 nematodes were extracted per gram of wood from branch samples collected from Scots, jack, and red pine trees at 14 weeks, respectively, and at 58 weeks an average of 13.82, 1.01, and 0.05 nematodes per gram of wood sampled were recovered. Proportions of branch samples with nematodes declined from 14 to 58 weeks after inoculation. Although limited mortality of branches occurred, the pine wood nematode was not found to cause tree death following inoculation.


2001 ◽  
Vol 133 (3) ◽  
pp. 343-353 ◽  
Author(s):  
Nathan W. Siegert ◽  
Deborah G. McCullough

AbstractHost preference of the pine shoot beetle, Tomicus piniperda (L.), was investigated in two laboratory choice test studies using red pine (Pinus resinosa Ait.) (Pinaceae), jack pine (Pinus banksiana Lamb.), and Scotch pine (Pinus sylvestris L.). Host preference of parent adult beetles was evaluated using freshly cut, similarly sized logs in a wind tunnel. Parent beetles colonized Scotch pine logs significantly more often when given a choice of Scotch pine and either red pine or jack pine logs, but did not show a preference when presented with red pine and jack pine logs. Host preference of progeny adults was tested in a laboratory bioassay using current-year pine shoots. Shoot-feeding progeny adults initiated tunnels in jack pine shoots significantly more often than in Scotch pine and red pine shoots, and preferred Scotch pine over red pine shoots. Shoots with diameters of 0.4–0.5 cm were attacked most frequently, regardless of species. Results suggest that the two North American pines are suitable hosts, but T. piniperda may be most likely to colonize Scotch pine, a European species. Efforts to detect or monitor T. piniperda populations in the Great Lakes and northeastern regions should focus on areas with abundant Scotch pine brood material. Progeny that emerge from brood material, however, may be as likely to shoot-feed in jack pine as in Scotch pine.


1952 ◽  
Vol 84 (2) ◽  
pp. 59-61
Author(s):  
A. S. West

Leconte's sawfly or the red-headed pine sawfly (Neodiprion lecontei Fitch) is a common insect attacking pines in Ontario. Plantations red pine are almost invariably attacked from the time the trees have reached two to four feet in height. Periodically epidemic populations cause significant damage. The life history and habits of the species have heen described by Middleton (2) who states that this insect attacks practically all species of pine as bell as larch. Schaffner (3) also indicates that the larvae feed on a wide variety of pine and occasionally on other conifers. Red pine (Pinus resinosa Ait.) is undoubtedly the usual host, although in Ontario jack pine (Pinus banksiana Lamb.) is sometimes attacked. In 1946 evidence was secured to show that jack pine needles may be selected for oviposition even in an area where red pine foliage is plentiful. (Figure 1).


1966 ◽  
Vol 44 (9) ◽  
pp. 1117-1120
Author(s):  
G. B. Ouellette

Through inoculation tests in the greenhouse and in the field, the previously unknown 0 and I stages of Coleosporium viburni Arth. are shown to occur on jack pine (Pinus banksiana Lamb.). These stages are described and differences in aeciospore morphology which permit distinction on pine of this rust from Coleosporium asterum (Diet.) Syd. are discussed. The description of C. asterum is amended to include differences in aeciospore size between collections on jack and red pine (Pinus resinosa Ait.). The known distribution of C. viburni is summarized.


1954 ◽  
Vol 86 (4) ◽  
pp. 167-168 ◽  
Author(s):  
H. C. Coppel

In collecting sawfly eggs, larvae, and cocoons for propagating beneficial insects at the Belleville laboratory, a heavy infestation of a pine sawfly, Neodiprion nanulus Schedl, was discovered in 1942 nine miles north of Belleville, on a 25-year-old plantation of red pine, Pinus resinosa Ait.; Scots pine, Pinus sylvestris L.; and jack pine, Pinus banksiana Lamb.From samples of the eggs collected in the spring of 1943, no parasites emerged.


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