International Journal of Bioresource Science
  • Year: 2024
  • Volume: 11
  • Issue: 1

Most Probable Number Bioassays and Trap Culture Techniques are Promising in Estimating Quantitative and Qualitative Arbuscular Mycorrhizal Fungi

  • Author:
  • Michael Sakha1,2,*, Joyce Jefwa2, Lydia Mutua3, Andrew Ogolla Egesa4, Pius Gumo1, Erick Otieno1, Joseph P. Gweyi-Onyango1
  • Total Page Count: 14
  • Published Online: Feb 21, 2025
  • Page Number: 1 to 14

1Department of Agricultural Science and Technology, Kenyatta University, Nairobi, Kenya

2The National Museums of Kenya Herbarium Department, Nairobi, Kenya

3Division of Academic, Co-operative Development, Research & Innovation, The Co-operative University of Kenya, Nairobi

4Environmental Horticulture Department, University of Florida, Gainesville, FL32611, Florida, USA

*Corresponding author: sirher.sakha225@gmail.com (ORCID ID: 0000-0001-5996-2261)

Online Published on 21 February, 2025.

Abstract

Arbuscular mycorrhizal (AM) fungi form a symbiotic relationship with plant roots and are the key functional group in soils. Several methods have been used traditionally to assess the mycorrhizal potential to colonize plants. The AM fungus is always quantified through direct analysis of field soil. However, the information obtained through this method is inaccurate and thus, there was the need to compare it with the most probable number (MPN) and trap culture techniques. The MPN and trap culture assay experiments were laid out in a glasshouse at the National Museums of Kenya in a Completely Randomized Design and replicated four times. MPN assay results revealed that the dilution levels differed significantly in root infectivity and percentage root colonization as quantified, and both of them reduced from the highest to the lowest dilution series. The standard media (commercial inoculant) elicited higher root infectivity than field soil. Besides, sorghum roots in standard media at dilution 4-4 had 18.75% root colonization intensity whereas in the same dilution level in soil, there was no root colonization. Four AMF genera (Scutellospora, Gigaspora, Acaulospora, and Glomus) were extracted in both field soil and trap culture. Moreover, a total of 42 and 78 spores were isolated and identified in field soil and trap culture respectively. These findings provide new insights into AMF species infectivity, colonization, and sporulation.

Arbuscular mycorrhizal (AM) fungi are the key functional group in soils, which forms symbiotic relationships with plant roots.

The study compared the conventional method of AM estimation with the most probable number (MPN) and trap culture techniques.

From both field and soil and trap culture, four AMF genera (Scutellospora, Gigaspora, Acaulospora, and Glomus) were extracted.

Hence the study provide new insights into AMF species infectivity, colonization, and sporulation.

Keywords

Colonization intensity, Infectivity, Inoculum, Propagule, Spore density, Sporulation