Fungal communities in mycorrhizal roots of conifer seedlings in forest nurseries under different cultivation systems, assessed by morphotyping, direct sequencing and mycelial isolation

Abstract

Fungi colonising root tips of Pinus sylvestris and Picea abies grown under four different seedling cultivation systems were assessed by morphotyping, direct sequencing and isolation methods. Roots were morphotyped using two approaches: (1) 10% of the whole root system from 30 seedlings of each species and (2) 20 randomly selected tips per plant from 300 seedlings of each species. The first approach yielded 15 morphotypes, the second yielded 27, including 18 new morphotypes. The overall community consisted of 33 morphotypes. The level of mycorrhizal colonisation of roots determined by each approach was about 50%. The cultivation system had a marked effect on the level of mycorrhizal colonisation. In pine, the highest level of colonisation (48%) was observed in bare-root systems, while in spruce, colonisation was highest in polyethylene rolls (71%). Direct internal transcribed spacer ribosomal DNA sequencing and isolation detected a total of 93 fungal taxa, including 27 mycorrhizal. A total of 71 (76.3%) fungi were identified at least to a genus level. The overlap between the two methods was low. Only 13 (13.9%) of taxa were both sequenced and isolated, 47 (50.5%) were detected exclusively by sequencing and 33 (35.5%) exclusively by isolation. All isolated mycorrhizal fungi were also detected by direct sequencing. Characteristic mycorrhizas were Phialophora finlandia, Amphinema byssoides, Rhizopogon rubescens, Suillus luteus and Thelephora terrestris. There was a moderate similarity in mycorrhizal communities between pine and spruce and among different cultivation systems.

Diversity of ectomycorrhizal fungus assemblages on nursery grown European beech seedlings

“…We discovered 27 taxa of ECM fungi on 2-year-old beech seedlings from four bare-root nurseries. The number of recognized taxa was richer than for conifers (Scots pine, Norway spruce, and European larch) and small-leaved lime (Menkis et al 2005;Iwański et al 2006;Rudawska et al 2006;Leski et al 2008;Timonen and Kauppinen 2008), but comparable with pedunculate and sessile oak (Leski et al 2010) grown in nursery conditions. Taxa richness in individual nurseries ranged from 6 to 13, and is a characteristic feature of each nursery rather than a methodological bias causing underestimation.…”

“…In conclusion, as noted for beech and other forest tree species (Menkis et al 2005;Iwański et al 2006;Rudawska et al 2006;Leski et al 2008Leski et al , 2010Timonen and Kauppinen 2008), ECM fungal communities in forest bare-root nurseries are fairly diverse and the level of colonization of seedlings is very high. We therefore agree with the opinion of Southworth et al (2009) that artificial inoculation in general is not necessary in nursery practice.…”

“…Our findings add to the evidence of a growing number of symbionts being able to colonize seedlings in nursery conditions, and emphasize the elucidation potential of molecular tools for detailed descriptions of ECM communities in different environments. Some of the identified fungi (Cenococcum, Tuber, Hebeloma, Laccaria) have been previously noted in forest nurseries as ECM symbionts of coniferous (Menkis et al 2005;Rudawska et al 2006;Leski et al 2008;Menkis and Vasaitis 2011) or deciduous hosts (Leski et al 2010), but some of them have been found for the first time in nursery conditions (Hydnotrya, Hymenogaster, Lactarius), or even as mycorrhizal partners of European beech (Naucoria, Geopora). For more details about the detected ECM fungi, see Online Resource 3.…”

Effect of organic fertilization and mulching on the growth of European larch (Larix decidua L.) and biological activity of soils

“…tworz¹ bardzo liczne mikoryzy u drzew iglastych w szkó³kach (Danielson 1991). Mikoryzy tworzone z udzia³em dwóch ostatnich gatunków grzybów licznie stwierdzano tak¿e u oewierka w szkó³kach (Menkis et al 2005;Rudawska et al 2006). Mikoryzy te, po wysadzeniu sadzonek na stanowiska sta³e, s¹ szybko zastêpowane przez inne grzyby ektomikoryzowe.…”

Evaluación del estado micorrícico de plántulas de Pinus ponderosa producidas bajo fertirriego, sin manejo de la micorrización

“…Numerosos estudios han demostrado la superioridad de las plántulas micorrizadas frente a las no micorrizadas en términos de establecimiento y supervivencia en campo, generando mejores respuestas a los crecimientos en las forestaciones (Gagnon et al 1988 y referencias allí incluidas, Stenström et al 1990, Krasowski et al 1999, Jumpponen 2001, Van Tichelen et al 2001, Dunabeitia et al 2004, Ortega et al 2004. Sin embargo, el manejo de la micorrización bajo sistemas que reciben fertilización requiere un estudio detallado para cada caso, dado que existen reportes contradictorios sobre el efecto inhibidor de la fertilización sobre la micorrización, dependiendo de las especies arbóreas y fúngicas involucradas (Menkis et al 2005).…”