Mix inoculation of native mycorrhiza and yeast on different Populus species growing in greenhouse condition

BOENEL, M; PASTORINO MJ; FONTENLA S; MESTRE MC; BOENEL, M; PASTORINO MJ; FONTENLA S; MESTRE MC

Valdivia

Workshop; Mycorrhizal Symbiosis in the Southern Cone of South America; 2017

In Argentina, there is an increasing interest on improving P opulus sp. production forlarge scale plantation. P opulus trees present both arbuscular mycorrhiza andectomycorrhiza colonization. Manipulation of mycorrhizal colonization could be animportant tool to enhance plant production. The aim of the present study was toevaluate the effect of two native yeasts on mycorrhizal colonization of P opulustrichocarpa and P . nigra produced under greenhouse condition. One year old, 30 cmcuttings were planted in pots containing sterile peat, clean sand and native soil(1:1:2). Yeast inoculation was performed in two steps: submerging the cutting in cellsuspensionfor 8 h before planting and spreading cell-suspension on cutting baseafter 20 days. Native soil from steppe was used as mycorrhizal inoculum. Chlorophyllcontains was measure as evaluation of plant health. Ectomycorrhizal presence wasevaluated by observation of fresh roots; and the percentage of arbuscularmycorrhizal colonization was evaluated on roots stain with tryphan blue. All plantswere healthy with similar level of chlorophyll. No ectomycorrhizal colonization wasobserved on any plant. Colonization by dark septate entophytes was observed asmicrosclerotia and hyphae in less than 10% of the roots. Vesicular-arbucularmycorrhizal colonization was observed in both tree species, with average rootcolonization over 50%. Two distinguishing patterns of colonization were observed:colonization by thick hyphae showing arbuscules, terminal vesicles and intracellularcoil structures; and colonization by fine hyphae with intercalar swollen andarbuscules. One of the yeast inoculated enhance mycorrhizal colonization, butstatistical differences to control treatment were not significant. The lack ofectomycorrhizal colonization could be attributed to plant age, but it has to be furtherinvestigated. The present work is a pioneer and innovative research for poplarproduction in Argentina. Greenhouse trials like the present one, allow the selectionof mycorrhization-helper microorganisms for future field experimentation.