20. The main function of mycorrhiza is
(1) Absorption of water
(2) Absorption of phosphates
(3) Protection from bacteria
(4) Defense from insects

The Core Function: Enhanced Nutrient Absorption

The primary function of mycorrhiza is to increase the absorption of nutrients, particularly phosphates, from the soil. Mycorrhizal fungi extend their hyphal networks far beyond the plant’s root system, penetrating soil microenvironments that roots alone cannot reach. Through this expanded network, they access and mobilize nutrients that would otherwise remain unavailable to the plant.

Why Phosphates?

Phosphorus is an essential macronutrient for plant growth, but it is often present in forms that are not easily accessible to plant roots. Mycorrhizal fungi are especially adept at absorbing phosphates and transferring them to their host plants, significantly improving phosphorus nutrition and overall plant vigor145.

Additional Benefits

While the main function is phosphate absorption, mycorrhizae also:

• Enhance the uptake of water and other minerals1235.

• Improve drought resistance and stress tolerance1237.

• Support soil structure and fertility157.

• Provide some protection against soil pathogens by promoting plant health26.

Answer to the Question

Given the options:

1. Absorption of water

2. Absorption of phosphates

3. Protection from bacteria

4. Defense from insects

The best answer is:

(2) Absorption of phosphates