new method to quantify the inoculum potential of arbuscular mycorrhizal fungi

• Published in: The New phytologist 1994-09, Vol.128 (1), p.89-92
• Main Authors: Liu, R.J, Luo, X.S
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Arbuscular mycorrhizut fungi; Biological and medical sciences; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Fungal spores; Fungi; Hyphae; Infections; Inoculation; Inoculum; inoculum density; inoculum potential; Mycorrhizal fungi; Nicotiana tabacum; Parasitism and symbiosis; pathogenicity; Plant physiology and development; Plant roots; Plants; propagules; quantitative analysis; Sorghum bicolor subsp. drummondii; Spores; Symbiosis; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); Trifolium repens; vesicular arbuscular mycorrhizae
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.1994.tb03990.x

Previously described concepts of inoculum potential (IP) and methods to measure the IP of arbuscular mycorrhizal fungi (AMF) are reviewed. The concept of IP is elusive and needs developing. A new definition of IP is described here as the number of viable fungal propagules and structures coupled with their initial infectivity, and the IP can be calculated from the formula IP = (N x W x K) + S or IP = (N x L) + S, where N = numbers of vesicles in roots and points of hyphae connected with the roots per unit length of the roots; W = root weight; K = root length per unit weight of the roots; L = root length; S = numbers of viable spores in an inoculum. For the AMF that produce spores in roots, few spores, or no spores, the formula becomes IP = N x W x K = N x L. The parameter of the IP is therefore the total numbers of vesicles and/or spores in roots, points of hyphae connected with roots, and viable spores in an inoculum of any type. The correlation coefficients between the IP of the inoculum of Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe, Glomus versiforme (Karsten) Berch, or Sclerocystis sinuosa Gerdemann & Bakhi and the amount of early stage infection produced by the corresponding inoculum were all > 0.93 (P < 0.01) on three host plants, Gossypium hirsutum L., Nicotiana tabacum L., or Sorghum sudanense L. It is suggested that the IP should be easily and rapidly estimated with accuracy by the present method.