The influence of varied microbial substrate conditions on the growth and mycorrhizal colonization of little bluestem (Schizachyrium scoparium (Michx.) Nash]

Abstract

SUMMARYTo determine the response of little bluestem [Schisachyrium scoparium (Michx.) Nash] to vesicular-arbuscular mycorrhizal (VAM) fungi, various microbial populations, and interactions between VAM fungi and other microbes plants were grown m three substrates; autoclaved soil, autoclaved soil to which VAM fungal-free sievmgs of non-autoclaved soil were added, and non-autoclaved soil. Mycorrhizal plants were established in autoclaved soil and in autoclaved soil receiving sievings by using little bluestem root pieces that were Cloroxtreated for 9 or 17 s as a source of VAM fungal inoculum. Exposure of root pieces to a 05 "" solution of sodium hypochlorite (Clorox) for 13-23 s, surface-sterilizes the roots, but it does not destroy viable internal VAM fungi. Control plants were grown in substrates receiving autoclaved root pieces. Plants grown in the autoclaved substrates had greater total biomass than plants grown m non-autoclaved soil. Inoculum type (autoclaved or surface sterilized root pieces) or addition of sievings had no effect on any growth parameter for plants grown in autoclaved soil. Mycorrhizal plants grown m the autoclaved substrate, not receiving sievmgs had higher tissue concentrations of P, Ca, S, Zn, Mn, and Fe than non-mycorrhizal plants grown m the same substrate. However, mycorrhizal plants did not produce more biomass than non-mycorrhizal plants in autoclaved substrates. Differences observed between plants grown m the autoclaved and non-autoclaved substrates are most likely attributable to greater nutrient ava.lab.l.tv of autoclaved substrates. The type of inoculum used and sub.strate conditions had negligible effects on rhizoplane and soil microbial populations. These included rhizoplane fungi and bacteria and selected functional groups of rh.zoplane microbes (cellulose, ch.tin, and protein decomposers).

Feeback between Plants and Their Soil Communities in an Old Field Community

“…The root inoculum of each plant species was then prepared by washing the remaining soil from the roots with water and cutting the roots into segments of < I em. These roots were not surface sterilized as in Meredith and Anderson (1992). A portion of each root inoculum was autoclaved and was used to make the physical effect of the roots consistent across the treatments, as described for the soil inocula.…”

The Fungal Root Endophyte Serendipita indica (Piriformospora indica) Enhances Bread and Durum Wheat Performance under Boron Toxicity at Both Vegetative and Generative Stages of Development through Mechanisms Unrelated to Mineral Homeostasis

“…Plant growth can be enhanced by soil sterilization through autoclaving or other techniques thanks to the elimination of soil-borne pathogens and competing micro-organisms [ 106 , 107 , 108 ]. In the present investigation, it appeared that soil sterilization resulted in significantly elevated shoot dry matters irrespective of S. indica , which is in agreement with the literature.…”

Positive density dependence in seedlings of the neotropical tree species Garcinia macrophylla and Xylopia micans

“…Seedlings used in this experiment were collected at least 20 m from adult conspecifics and were surface‐sterilized in a dilute (5%) solution of bleach prior to planting. This sterilization removes fungal or bacterial pathogens and mutualists on the surface of the roots, but not in the interior of the root system (Meredith & Anderson 1992). Preliminary observations indicated that treatment in bleach did not impede subsequent performance.…”