Seasonal variation in mycorrhizal fungi colonizing roots of Allium tricoccum (wild leek) in a mature mixed hardwood forest

Abstract

The community of arbuscular mycorrhizal (AM) fungi colonizing roots of the forest herb Allium tricoccum Ait. (wild leek) was examined to assess whether colonization varied seasonally and spatially within the forest. Whole plants were collected to coincide with observed phenological stages, and the perennial tissue (i.e., the bulb) was used to analyze total C, N, and P over the growing season. AM fungal community composition, structure, and abundance were assessed in roots by terminal restriction fragment length polymorphism analysis and quantitative PCR. It was found that A. tricoccum rDNA co-amplified using the general AM primers NS31/AM1, and a new primer for qPCR was designed that discriminated against plant DNA to quantify AM colonization. Community structure of AM fungi did not vary seasonally, but did change spatially within the forest, and AM fungal communities were correlated with the presence of overstory tree species. Fungal colonization of roots, however, did change seasonally with a maximum observed in late winter and early spring following leaf emergence. Maximum AM fungal colonization was associated with declines in bulb N and P, suggesting that leaf emergence and growth were responsible for both declines in stored nutrients and increases in AM fungal colonization. Plant N and P contents increased between late summer and early spring while C contents remained unchanged. The observed increase in nutrient content during a time when A. tricoccum lacks leaves indicates that the roots or AM fungi are metabolically active and acquire nutrients during this time, despite an absence of photosynthesis and thus a direct supply of C from A. tricoccum.

Microbial inoculation influences arbuscular mycorrhizal fungi community structure and nutrient dynamics in temperate tree restoration

“…These five samples were randomly selected from the DNA extractions used in our TRFLP analysis. Each 25‐μL reaction contained 1 μL of template DNA, 10‐μL SYBR Green Supermix (Bio‐Rad), and 0.8 μL of primers AMG1F and AM1 (see Hewins et al for primer information). Thermal cycling conditions were 95°C for 4 minutes, followed by 30 cycles of 95°C for 30 seconds, 58°C for 1 minute, and 72°C with for 90 seconds with plate reads at 90‐second intervals following the 72°C step.…”

Iron Oxide and Titanium Dioxide Nanoparticle Effects on Plant Performance and Root Associated Microbes

“…The PCR was carried out on a PTC 100 Thermal Cycler (MJ Research, Boston, MA, USA) using cycling conditions in Helgason et al except that 32 cycles were used for PCR and the annealing temperature was 60 °C [ 38 ]. The primer NS31 was labeled with the fluorochrome HEX (4,7,2ʹ,4′,5′,7′-hexachloro-6-carboxyfluorescein) and PCR product was used for analysis of AM fungal communities using terminal restriction fragment length polymorphism procedures [ 40 ]. PCR product was digested with the restriction enzyme Hinf I (Promega, Madison, WI, USA) and TRFLPs were completed through the Cornell Bioresource Center using an Applied BioSystems 3730xl DNA Analyzer and the GS600 LIZ size standard.…”

“…, major TRFs) [ 41 ]. To estimate root length colonized by AM fungi, we used quantitative PCR (qPCR) using primer AM1 and primer AM1GF, which generates an approximately 210 base pair long amplicons [ 40 ]. The qPCR was conducted in 20 μL reaction volumes using 1× iTaqUniversal™ SYBR ® Green Supermix (Bio-Rad) on a MiniOpticon™ real-time PCR detection system (Bio-Rad Laboratories, Inc., Hercules, CA, USA) following procedures developed by Hewins et al [ 40 ].Colonization is reported as copy number per gram of dry root tissue.…”

Utilizing herbarium specimens to quantify historical mycorrhizal communities

“…TABLE 1. Arbuscular mycorrhizal fungi (AMF) clones recovered from herbarium root samples in the current study using primers AMG1F and AM1 (see Hewins et al, 2015 Of 48 clones, two did not sequence properly and three were high matches (e.g., 99%) to other non-AMF taxa. Forty-three clones were good matches to AMF taxa as determined using the BLAST tool through the National Center for Biotechnology Information (NCBI).…”