Reading reflection - 4/3/13

The Role of Endomycorrhizae in Revegetation Practices in the Semi-Arid West. II. A Bioassay
to Determine the Effect of Land Disturbance on Endomycorrhizal Populations.
Author(s): Thomas Moorman and F. Brent ReevesSource: American Journal of Botany, Vol. 66, No. 1 (Jan., 1979), pp. 14-18.

This article points out that populations of endomycorrhizae fungus were significantly reduced following land disturbance in Colorado soils.VA mycorrhizal fungi can survive in the soil in plant roots, or as spores in the soil. Surprisingly, the disturbed soil contained significantly greater numbers of spores of VA mycorrihizal fungi, however most spores observed were cracked or dead. An average of 6.7 spores per g in undisturbed soil was found compared to an average of 10.4 spores in the disturbed soil. However, previous studies have shown that spores are not the the principal source of inoculum, but that infected plant roots or mycelium in the soil were important sources of inoculum. Spore counts are inconclusive due to factors on the production of spores such as plant nutrients, season, and host plants.
Therefore, a bioassay was developed to measure changes in the endomycorrhizae population. In the bioassay, inoculum levels were measured by comparing the percentage infection in corn (Zea mays) root systems thirty days after planting in undisturbed or disturbed soils. The bioassay measures the relative amounts of inoculum in the soils by observing the amount of development of mycorrhizal fungi in the host plants.Corn is utilized becasue it is known to host many VA mycorrhizal fungi. The percentage infection was 2% in the disturbed soil compared to 77% in the adjacent undisturbed soil. The correlation between the incidence of active mycorrhizal propagules and the incidence of mycorrhizal plants in these soils. This correlation has far reaching implications in restoring disturbed ecosystems and habitats.

AM incolum fungal production

MIP bioassay