Inheritance of Rust Resistance in Southern Pines

Reliability of field, greenhouse and cut‐shoot screening procedures for evaluating susceptibility of Scots pine to Melampsora pinitorqua

“…Changes in morphological and physiological mechanisms of resistance during the maturation stage of the shoot tissues could explain the differences observed in the degree of rust susceptibility (BJORKMAN 1966;HARE 1972;KINLOCH 1982). Maturity of shoot tissue could have an in¯uence on disease expression.…”

“…Maturity of shoot tissue could have an in¯uence on disease expression. Changes in morphological and physiological mechanisms of resistance during the maturation stage of the shoot tissues could explain the differences observed in the degree of rust susceptibility (BJORKMAN 1966;HARE 1972;KINLOCH 1982). Although twisting rust susceptibility is expected to decrease with age according to ®eld observations, the good relationships obtained between excised shoot from 5-to 6-year-old trees and seedling evaluations showed that ontogenetic changes did not seem to be of major importance in the expression of susceptibility in this age range and under our experimental conditions.…”

Genetics of slash pine /

“…Amount of volume gain will vary among studies because of the emphasis that may be given to other traits besides volume when selections are made. No immunity to pests has been found in slash pine, but offspring of certain trees have shown important amounts of resistance to fusiform rust or cone and seed insects (Jewell 1966; Sartor and Neel 1971).…”

Identification of Nine Pathotype-Specific Genes Conferring Resistance to Fusiform Rust in Loblolly Pine (Pinus taeda L.)

“…The OP families were useful for recognizing resistant and susceptible selections, and the full sib data led Jewell [12] to propose that resistance in slash pine was controlled by a dominant single gene, but later Jewell and Mallett [13], with additional disease data from full-sib seedlings from resistant selections 8-7 and 18-27, deemed resistance in slash pine to be more complex. Kinloch and Walkinshaw [14], in a reanalysis of an earlier study by Griggs and Walkinshaw [15] that used full-sib slash pine families from a five parent diallel cross (including resistant parents, 8-7 and 18-27 used in works [12,13]) challenged with basidiospore inocula derived from two single galls, reported fusiform rust resistance involving dominant single host genes, two in that study, and based on the data hypothesized gene-for-gene interactions. Powers [16] and Kuhlman and Matthews [17] reported methods for the development of single-genotype Cqf isolates with the Kuhlman and Matthews work showing virulence variation among single-genotype isolates derived from the same single gall.…”

“…Jewell [12] based on a series of artificially inoculated trials, using expectedly diverse basidiospore inocula obtained from naturally infected oak leaves OP slash pine families from rust-free and rust-infected selections as well as full-sib families from rust-free and rust-infected slash pine selections, reported disease data summarized from several years of work. The OP families were useful for recognizing resistant and susceptible selections, and the full sib data led Jewell [12] to propose that resistance in slash pine was controlled by a dominant single gene, but later Jewell and Mallett [13], with additional disease data from full-sib seedlings from resistant selections 8-7 and 18-27, deemed resistance in slash pine to be more complex.…”