Arbuscular mycorrhizal induced changes to plant growth and root system morphology in Prunus cerasifera

Abstract

We compared root system morphogenesis of micropropogated transplants of Prunus cerasifera L. inoculated with either of the arbuscular mycorrhizal (AM) fungi Glomus mosseae or Glomus intraradices or with the ericoid mycorrhizal species Hymenoscyphus ericae. All plants were grown in sand culture, irrigated with a nutrient solution that included a soluble source of phosphorus, for 75 days after transplanting. Arbuscular mycorrhizal colonization increased both the survival and growth (by over 100%) of transplants compared with either uninoculated controls or transplants inoculated with H. ericae. Arbuscular mycorrhizal colonization increased root, stem and leaf weights, leaf area, root length and specific leaf area, and it decreased root length/leaf area ratio, root/shoot weight ratio and specific root length. Both uptake of phosphorus and its concentration in leaves were increased by AM infection, although the time course of the relationships between intensity of AM infection and P nutrition were complex and suggested a role for factors other than nutrition. The time course for the development of infection varied. It was most rapid with G. mosseae, but it was ultimately higher with G. intraradices. None of the treatments significantly affected the lengths of adventitious roots or the first-, second- or third-order laterals that developed from them. Arbuscular mycorrhizal colonization increased the intensity of branching in all root orders with the effect being most obvious on first-order lateral roots where the number of branches increased from under 100 to over 300 brances m(-1). As a result, although first-order laterals made up 55% of the root systems of control plants, the comparable value was 36% in AM-infected plants. In contrast, second-order laterals represented 25% of control root systems, but 50% of AM-colonized root systems. Glomus intraradices but not G. mosseae increased root diameter. Anatomical studies revealed no changes in the overall form of the root tip, although there were changes in the diameter of the root cap, cell numbers and cell size. Hymenoscyphus ericae increased the duration of the metaphase index. Both AM fungal treatments increased the concentrations of soluble proteins in root extracts and modified the protein profiles by the elimination and addition of protein bands detected by PAGE analysis. We conclude that AM fungal inoculation influenced processes in the root system at different levels, but not all effects were due to improved P nutrition or increased physiological age.

The Influence of Bioproducts on Mycorrhizal Occurrence and Diversity in the Rhizosphere of Strawberry Plants under Controlled Conditions

“…The correlation found among root diameter, surface area and mycorrhizal frequency (Figure 2) is underlining the effect of AMF inoculation on root morphology [34]. Similarly, the negative relations found between the amount of nutrients and root growth parameters and mycorrhizal inoculation is confirming the negative effect of mineral fertilization on the growth of the root system and on the establishment of the mycorrhizal symbiosis [54].…”

“…Root morphological parameters (total root length, root diameter, root surface area, root volume and total number of root tips) were measured by an image analysis system with an Epson scanner controlled by WinRhizo software (Regent Instruments Inc.). The degree of branching of the root system was calculated as the ratio between the total number of roots and their total length [34].…”

Interactions between arbuscular mycorrhizal fungi and phosphate-solubilizing fungus (Mortierella sp.) and their effects on Kostelelzkya virginica growth and enzyme activities of rhizosphere and bulk soils at different salinities

“…Plants inoculated with three fungi had significantly lower root dry matter than plants inoculated with Gm and Ms, probably due to the lower mycorrhizal root colonization of the former plants. However, inoculation of AMF and Ms may increase root development and nutrient uptake, and this may decrease root/shoot ratios (Kothari et al 1990;Berta et al 1995).…”

Interactions between plant‐growth‐promoting rhizobacteria (PGPR), arbuscular mycorrhizal fungi and Rhizobium spp. in the rhizosphere of Anthyllis cytisoides, a model legume for revegetation in mediterranean semi‐arid ecosystems

“…Plants were dried at 60 °C for 24 h and their d. wt determined. Specific root length (SRL) was studied, as it is a parameter which can be correlated with morphological features taking place in root architecture derived from changes in the branching pattern of the root (Berta et al, 1995;Barea et al, 1996). It was calculated thus: total root length/total d. wt.…”