Mode of Penetration of Needles of Eastern White Pine by Cronartium ribicola

Seedling survival of Pinus strobus and its interspecific hybrids after artificial inoculation of Cronartium ribicola

“…Large differences in mortality among the OP families were observed at the point in the experiments when 50% of the seedlings had died, resulting in moderately high heritability estimates ( Table 2). These results reflected the findings of other eastern white pine studies (Riker et al, 1943;Riker and Patton, 1954;Patton, 1967;Patton and Johnson, 1970;Jurgens et al, 2003) that indicated that partial resistance might have reduced infection and/or delayed mortality.…”

Survival, growth and wood specific gravity of interspecific hybrids of Pinus strobus and P. wallichiana grown in Ontario

“…resistance has occurred in North America for more than half a century (Riker et al, 1943;Riker and Patton, 1954;Heimburger, 1962Heimburger, , 1972Patton, 1967;Patton and Johnson, 1970). Relatively resistant white pine genotypes were selected with various resistance mechanisms, such as ontogenetic resistance, slow rusting, and bark reactions (Patton, 1967;Patton and Johnson, 1970;Jurgens et al, 2003), and genetic gains were shown in some field tests (Zsuffa, 1981;Sinclair, 2003).…”

“…resistance has occurred in North America for more than half a century (Riker et al, 1943;Riker and Patton, 1954;Heimburger, 1962Heimburger, , 1972Patton, 1967;Patton and Johnson, 1970). Relatively resistant white pine genotypes were selected with various resistance mechanisms, such as ontogenetic resistance, slow rusting, and bark reactions (Patton, 1967;Patton and Johnson, 1970;Jurgens et al, 2003), and genetic gains were shown in some field tests (Zsuffa, 1981;Sinclair, 2003). In cases where blister rust inoculum density is high, such as in an artificial inoculation, evidence suggests that the levels of resistance in P. strobus may be insufficient to withstand heavy blister rust attack, especially at seedling stages (Heimburger, 1972;Zsuffa, 1981;Sniezko and Kegley, 2002;Lu et al, 2005).…”

Breeding eastern white pine for blister rust resistance: A review of progress in Ontario

“…Unlike other North American 5-needle pine species, such as sugar pine (P. lambertiana) and western white pine (P. monticola) in which some rare major resistance genes have been found (Kinloch and Comstock 1980;Kinloch et al 1999Kinloch et al , 2003Kinloch , 2004Sniezko 2006;Sniezko et al 2008), this mechanism has yet to be discovered in eastern white pine despite more than half a century's search in its natural populations. Although differences occur among eastern white pine genotypes in their response to blister rust infection, such as morphological barriers to blister rust invasion, ontogenetic resistance, slower rusting, and bark reactions (Riker et al 1943, Riker and Patton 1954, Patton 1967, Patton and Johnson 1970, Garrett 1985, Smith et al 2002, Jurgens et al 2003, the strength of overall resistance conferred by these mechanisms is questionable in protecting saplings from blister rust attack.…”