Variation in the ability to form ectomycorrhizas in the F1 progeny of an interspecific poplar (Populus spp.) cross

Abstract

The aim of this study was to determine the existence of a genetic basis for the ability to form ectomycorrhiza on a model angiosperm tree (Populus, poplar). Parental clones and 18 progeny from a controlled interspecific cross between Populus deltoides and Populus trichocarpa were grown in a glasshouse and inoculated with mycelium of the ectomycorrhizal fungus Laccaria bicolor. Three months after inoculation, the percentage of mycorrhizal root tips was determined for each inoculated plant. The data indicate variability in the ability to form ectomycorrhizas among the F1 progeny, including individual progeny which are different to either parent. This suggests a genetic basis for mycorrhiza formation.

Former Land Use and Host Genotype Influence the Mycorrhizal Colonization of Poplar Roots

“…Our findings and that of Gehring et al [8], Khasa et al [10], Tagu et al [11,12], van der Heijden and Kuyper [13] and Walker and McNabb [14] imply that both factors, former land use and clone type, are important determinants of mycorrhizal colonization. The land use types represented, beside the abiotic factors, the different inoculum capacities and were therefore the most important factors determining the mycorrhizal abundance and diversity on the roots of poplars.…”

“…During the early stage of growth, the main colonizers of poplar roots are AM fungi, which are subsequently replaced by ECM fungi [15]. The ratio between ECM and AM colonization of poplars is showing a broad range and has been found to be influenced by environmental factors and host genetics [10][11][12][13][14]. Plant genotypes have been shown to differ in both their ability to form mycorrhiza, and in the relative benefit received from this mycorrhizal colonization [9,30].…”

“…Although most plant species generally form only one of the several possible types of mycorrhizal associations, poplars are among the few commercially important trees that form tripartite symbiotic associations with ECM and AM fungi [6,7]. Whereas some studies consider that the colonization by AM versus ECM fungi is influenced by the local soil environment [8,9], other studies also suggest that host plant genetics may play a role in determining the dominant mycorrhizal type in dually colonized hosts [10][11][12][13][14]. Neville et al [15] described that during the juvenile stage of growth, the main colonizers of poplar roots are AM fungi, which are subsequently replaced by ECM fungi.…”

Genome Resequencing in Populus: Revealing Large-Scale Genome Variation and Implications on Specialized-Trait Genomics

“…We hypothesize that signifi cant advances in understanding these highly specifi c interaction can be made by focusing on the types of polymorphisms that occur at the species level. Tagu et al ( 2001 ) reported signifi cant segregation in Populus colonization by the symbiont Laccaria bicolor in F 1 progeny from a P. trichocarpa x P. deltoides interspecifi c cross. Further, Labbé et al ( 2011 ) suggested preferential colonization of P. trichocarpa compared to P. deltoides and mapped QTL associated with percent colonization in the F 1 pedigree family 54B.…”

Fair Trade in the Underworld: the Ectomycorrhizal Symbiosis

“…The ability of poplar trees to form ectomycorrhizas is under genetic control (Tagu et al 2001). Heritability of the ectomycorrhizal trait was investigated in Pinus elliottii (Rosado et al 1994) and a strong narrow-sense heritability was found (0.81) for the percentage of ectomycorrhizas formed.…”