Resistance of Pinus banksiana to the European race of Gremmeniella abietina

Abstract

Au début des années 80, plus de 90 % de mortalité causée par Gremmeniella abietina, race européenne, a été relevée dans des plantations de pin rouge (Pinus resinosa) localisées à environ 200 km au nord-ouest de Montréal, Québec, Canada. Les pins gris ( Pinus banksiana) avoisinants ne semblaient pas attaqués. Les forestiers ont donc reboisé ces aires avec des semis de pin gris. Des parcelles d'études de 100 pins gris ont été établies dans trois plantations sur les quatre sélectionnées en 1988. Comme références, des semis de pin rouge ont été plantés dans des conditions semblables dans la quatrième plantation en 1989. Les observations annuelles se sont déroulées de 1989 à 1992. La mortalité des semis de pin rouge atteignait 70 % en 1992 alors que les pins gris des trois sites expérimentaux n'étaient pas attaqués, à l'exception d'une brûlure à l'extrémité des pousses, caractéristique qui permet d'identifier la race au champ. Les symptômes de la race nord-américaine étaient présents à un taux très bas; leur incidence a augmenté sur le site I en 1992. Plus de 10 ans après la plantation, les pins gris montrent une résistance à la race européenne de G. abietina alors que tous les pins rouges sont morts.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

Resistance of Pinus contorta to the European race of Gremmeniella abietina

“…1997) but little is known about the resistance mechanisms to this disease. Recently, it has been demonstrated that jack pine is resistant to the EU race ( Laflamme and Blais 2000) and defence reactions have been described ( Simard et al. 2001).…”

Enzymatic interactions between Gremmeniella abietina var. abietina, European race, and two resistant hosts, Pinus banksiana and P. contorta

“…abietina EU race, 2-year-old jack and lodgepole pine seedlings were planted adjacent to 25-year-old red pine trees naturally infected by the EU race (Laflamme and Blais 2000;Laflamme et al 2006). abietina EU race, 2-year-old jack and lodgepole pine seedlings were planted adjacent to 25-year-old red pine trees naturally infected by the EU race (Laflamme and Blais 2000;Laflamme et al 2006).…”

“…To test their resistance to Gremmeniella abietina var. abietina EU race, 2-year-old jack and lodgepole pine seedlings were planted adjacent to 25-year-old red pine trees naturally infected by the EU race (Laflamme and Blais 2000;Laflamme et al 2006). These plantations are located about 200 km northwest of Montreal, QC, Canada (46°39′N, 75°16′W).…”

Resistance toGremmeniella abietina(European race, large tree type) in introducedPinus contortaand nativePinus sylvestrisin Sweden

“…In Canada, P. banksiana has shown resistance to G. abietina (EU race) under field conditions (Laflamme and Blais 2000). A histological study was conducted on these infected pine shoots; observation demonstrated that lignosuberized tissues confine the pathogen within the necrotic area (Simard et al 2001).…”