Genetically determined fungal pathogen tolerance and soil variation influence ectomycorrhizal traits of loblolly pine

Abstract

Selection on genetically correlated traits within species can create indirect effects on one trait by selection on another. The consequences of these trait correlations are of interest because they may influence how suites of traits within species evolve under differing selection pressures, both natural and artificial. By utilizing genetic families of loblolly pine either tolerant (t) or susceptible (s) to two different suites of pathogenic fungi responsible for causing either pine decline or fusiform rust disease, we investigated trait variation and trait correlations within loblolly pine (Pinus taeda L.) by determining how ectomycorrhizal (EM) colonization relates to pathogen susceptibility. We detected interactions between susceptibility to pathogenic fungi and soil inoculation source on loblolly pine compatibility with the EM fungi Thelephora, and on relative growth rate of loblolly pine. Additionally, we detected spatial variation in the loblolly pine–EM fungi interaction, and found that variation in colonization rates by some members of the EM community is not dictated by genetic variation in the host plant but rather soil inoculation source alone. The work presented here illustrates the potential for indirect selection on compatibility with symbiotic EM fungi as a result of selection for resistance to fungal pathogens. Additionally, we present evidence that the host plant does not have a single “mycorrhizal trait” governing interactions with all EM fungi, but rather that it can interact with different fungal taxa independently. Synthesis. An understanding of the genetic architecture of essential traits in focal species is crucial if we are to anticipate and manage the results of natural and artificial selection. As demonstrated here, an essential but often overlooked symbiosis (that between plants and mycorrhizal fungi) may be indirectly influenced by directed selection on the host plant.

Heritable genetic variation but no local adaptation in a pine-ectomycorrhizal interaction

“…For example, Pinus edulis individuals resistant to attack by a stem boring moth were found to harbour different EM communities (Sthultz et al, 2009), which provided differing amounts of host benefit under increasing drought (Patterson et al, 2018;Gehring et al, 2014). Similarly, genotypes of P. taeda resistant to two fungal pathogens showed both variation in compatibility with specific fungal genera and variation in relative growth rate (Piculell et al, 2018). Evidence of similar effects has also been hinted at in angiosperms, with fungal leaf pathogen communities strongly correlating with EM fungal communities (Lamit et al, 2015).…”

Plant intraspecific variation modulates nutrient cycling through its below ground rhizospheric microbiome

“…Pines are obligatory ectomycorrhizal (ECM) plants and this intimate relationship strongly influences the surrounding environment (Tarkka, Drigo, & Deveau, ). The effects of the plant genotype on below‐ground microbial communities can be ideally studied through the symbiosis between pines and ECM fungi (Patterson, Flores‐Rentería, Whipple, Whitham, & Gehring, ; Pérez‐Izquierdo et al, ; Piculell, Eckhardt, & Hoeksema, ). Patterson et al () have recently shown that ECM community composition is under strong plant genetic control in Pinus edulis .…”

“…ecosystem functioning, ectomycorrhizal fungi, nutrient cycling, phylogenetic community structure, plant genotype, rhizosphere, soil bacteria (Patterson, Flores-Rentería, Whipple, Whitham, & Gehring, 2018;Pérez-Izquierdo et al, 2017;Piculell, Eckhardt, & Hoeksema, 2018). Patterson et al (2018) have recently shown that ECM community composition is under strong plant genetic control in Pinus edulis.…”

Efecto de ácidos húmicos, micorrizas y quitosano en indicadores del crecimiento de dos cultivares de tomate (Solanum lycopersicum L.)

“…Adicionalmente, la disminución o desaparición de la microflora residente en los suelos y el incremento de patógenos que afectan de manera drástica a los cultivos. Todo lo cual ha traído como consecuencia daños a la salud humana y animal (Emamverdian et al, 2015;Plá y Cobos-Porras, 2015;Singh, 2015;Piculell et al, 2018).…”

“…Some of the most notable consequences are the increase of affected areas by salt excess and ground water contamination with toxic ions besides the decrease or disappearance of resident microflora in soils and the increase of pathogens that affect cultivations drastically. All these has brought as a consequence harmful effects on human and animal health (Emamverdian et al, 2015;Plá and Cobos-Porras, 2015;Singh, 2015;Piculell et al, 2018).…”