Ectomycorrhizal fungal communities of pedunculate and sessile oak seedlings from bare-root forest nurseries

Abstract

In this study, we present the detailed molecular investigation of the ectomycorrhizal (ECM) community of Quercus petraea and Quercus robur seedlings grown in bare-root forest nurseries. In all tested oak samples, mycorrhizal colonization was nearly 100%. Morphological observation and molecular investigations (sequencing of fungal ITS rDNA) revealed a total of 23 mycorrhizal taxa. The most frequent and abundant fungal taxa were Hebeloma sacchariolens, Tuber sp., and Peziza sp.; from the detected fungal taxa, 20 were noted for Q. petraea and 23 for Q. robur. Depending on the nursery, the species richness of identified ECM fungal taxa for both oak species ranged from six to 11 taxa. The mean species richness for all nurseries was 5.36 and 5.82 taxa per Q. petraea and Q. robur sample, respectively. According to the analysis of similarity, ECM fungal communities were similar for Q. petraea and Q. robur (R = 0.019; p = 0.151). On the other hand, detected fungal communities were significantly different between nurseries (R = 0.927; p < 0.0001). Using the Spearman rank correlation, it was determined that the ectomycorrhizal diversity (in terms of richness, the Shannon diversity, evenness, and Simpson dominance indices) is significantly related to the soil parameters of each nursery. We conclude that individual nursery may be considered as separate ecological niches that strongly discriminate diversity of ECM fungi.

Diversity of ectomycorrhizal fungus assemblages on nursery grown European beech seedlings

“…Of the 27 recognized fungal taxa, only 6 were found in more than one nursery. The occurrence of ECM fungi in nurseries with a frequency of only one agrees with the findings of studies carried out by Leski et al (2010) on European oak seedlings, and supports our concept that each nursery had a unique structure of ECM assemblages. This is further confirmed by the ANO-SIM and NMDS analyzes that have clearly shown that ECM fungal communities differed significantly between the nurseries (Fig.…”

“…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.…”

“…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.…”

“…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.…”

Successional traits of ectomycorrhizal fungi in forest reclamation after surface mining and agricultural disturbances: A review

“…The best results are expected when fungal inocula are specifically adapted to the environmental conditions of transplantation sites (Rincón et al, 2007). However, if not intentionally mycorrhized, tree seedlings usually get colonized by native ECM fungi during their development in nurseries (Leski et al, 2010;Pietras et al, 2013). Inoculated or nursery-originated ECM species are often poor competitors among field conditions (Danielson & Visser, 1989;Xu et al, 2001;Rincón et al, 2007), but they can help seedlings to develop new short roots susceptible to the colonization of indigenous ECM symbionts (Grossnickle, 2005), or to increase the overall percent of ECM root mycorrhization (Onwuchekwa et al, 2014).…”