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

PASTORINO M; BOENEL M; MESTRE M. C.; FONTENLA S

Valdivia

Workshop; Mycorrhizal symbiosis in the southern cone of south America; 2017

Universidad Austral de Chile

In Argentina, there is an increasing interest on improving Populus sp. production for large scale plantation. Populus trees present both arbuscular mycorrhiza and ectomycorrhiza colonization. Manipulation of mycorrhizal colonization could be an important tool to enhance plant production. The aim of the present study was to evaluate the effect of two native yeasts on mycorrhizal colonization of Populus trichocarpa and P. nigra produced under greenhouse condition. One year old, 30 cm cuttings 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 cell-suspension for 8 h before planting and spreading cell-suspension on cutting base after 20 days. Native soil from steppe was used as mycorrhizal inoculum. Chlorophyll contains was measure as evaluation of plant health. Ectomycorrhizal presence was evaluated by observation of fresh roots; and the percentage of arbuscular mycorrhizal colonization was evaluated on roots stain with tryphan blue. All plants were healthy with similar level of chlorophyll. No ectomycorrhizal colonization was observed on any plant. Colonization by dark septate entophytes was observed as microsclerotia and hyphae in less than 10% of the roots. Vesicular-arbucular mycorrhizal colonization was observed in both tree species, with average root colonization over 50%. Two distinguishing patterns of colonization were observed: colonization by thick hyphae showing arbuscules, terminal vesicles and intracellular coil structures; and colonization by fine hyphae with intercalar swollen and arbuscules. One of the yeast inoculated enhance mycorrhizal colonization, but statistical differences to control treatment were not significant. The lack of ectomycorrhizal colonization could be attributed to plant age, but it has to be further investigated. The present work is a pioneer and innovative research for poplar production in Argentina. Greenhouse trials like the present one, allow the selection of mycorrhization-helper microorganisms for future field experimentation.