Which one of the following helps in absorption of phosphorus from soil to the plants ?

Glomus

Among the options provided, the microbe that helps in the absorption of phosphorus from soil to plants is Glomus. Glomus is a type of mycorrhizal fungus that forms a mutualistic association with the roots of plants, known as arbuscular mycorrhiza. In this symbiotic relationship, the Glomus fungus colonizes the root system of the plant, forming specialized structures called arbuscules and vesicles.

One of the significant benefits of this association is the enhanced nutrient uptake, including phosphorus. The hyphal network of Glomus extends into the surrounding soil, effectively exploring a larger volume of soil and accessing phosphorus that may be less available to the plant's roots alone. The fungus solubilizes and absorbs phosphorus from the soil, making it more accessible for the plant. In return, the plant provides the fungus with carbohydrates as a source of energy.

Rhizobium, Nostoc, and Azospirillum are other types of beneficial microbes, but they primarily play roles in nitrogen fixation (Rhizobium and Nostoc) and promoting plant growth through other mechanisms (Azospirillum).