Root–fungus mutualism — defining mycorrhizae Mycorrhizae are best described as symbiotic associations between which two partners?

Introduction / Context:
Mycorrhizal relationships are among the most widespread and ecologically important symbioses on land. They directly influence plant nutrition, soil structure, and ecosystem productivity.

Given Data / Assumptions:

• The term “mycorrhiza” literally combines “myco-” (fungus) and “-rhiza” (root).
• We are identifying the two biological partners.
• The association is mutualistic under normal conditions.

Concept / Approach:

Mycorrhizae form when fungal hyphae associate with plant roots, either externally (ectomycorrhizae) or within root cortical cells (endomycorrhizae/arbuscular mycorrhizae). Plants benefit from improved access to immobile nutrients (especially phosphorus), while fungi receive carbohydrates from plant photosynthesis.

Step-by-Step Solution:

Verification / Alternative check:

Standard botany and ecology sources uniformly describe mycorrhizae as plant root–fungus associations, distinct from lichens (algae/cyanobacteria + fungi).

Why Other Options Are Wrong:

Algae–fungi refers to lichens; bacteria–root refers to rhizobia nodulation; bacteria–fungi and algae–bacteria are not mycorrhizae.

Common Pitfalls:

Assuming “mycorrhiza” involves algae due to familiarity with lichens; remember “rhiza” points to roots.

Final Answer:

Root and fungi