Question

Select correct statements w.r.t. mycorrhiza
A. Ectomycorrhiza forms hartig net in the intercellular spaces of cortex cells
B. Endotrophic mycorrhiza are mostly basidiomycetes members
C. VAM is a special type of endomycorrhiza and absorbs phosphate
D. Mycorrhizal or fungal roots have root cap and root hairs.

Answer 1

Fungi are groups of eukaryotic organisms which include both the unicellular and multicellular types. They are represented by species of unicellular yeasts and multicellular mushrooms. The fungi are saprophytic in nature but in certain conditions, they are found to exist in symbiotic association with the plants.

Complete answer:
A mycorrhiza is a type of symbiotic relation between the fungi and the plants. Mycorrhizal association can be of two types which are ectomycorrhizal and endomycorrhiza. When the association between the fungi and plant tissues takes place by means of extracellular association is called ectomycorrhizas. In this condition, the hyphae of the fungi don’t enter individual cells that are present within the roots. They only enter and invade the intercellular spaces. The hyphal network in the ectomycorrhizae are known as hartig net as they form a network of hyphae without entering the cells of the cortex. There is no root present in the mycorrhiza; instead they enter the plant tissues with the help of hyphae.
In the endomycorrhiza, the association is more intimate as the hyphae of the fungi enters into the cell wall and invaginates the cell membrane. The endotrophic mycorrhiza form a special type of mycorrhizas which are known as arbuscular mycorrhizas of vesicular- arbuscular mycorrhizas (VAM). In this condition, the hyphae penetrate the plant cells and give rise to structures such as swollen vesicles or branched invaginations. The branched invaginations are called arbuscules.
The VAM helps to facilitate the transfer of nutrients between the cell of the plants and fungal hyphae. It is particularly important in the absorption of phosphate.
The endotrophic mycorrhiza is generally formed by the members of the fungi in the division Glomeromycota while the ectomycorrhizal are formed by members of the Basidiomycota, Ascomycota and Zygomycota.

Hence, the correct answer is option (C).

Additional information:
The fungi is generally present in the rhizosphere or the root system of the plant. In this type of association, the fungus invades the tissues of the root of the host plant and derives nourishment from it. The fungi enter into the host tissue either intracellularly or extracellularly. The plant prepares its food in the form of inorganic molecules which are sugars during the process of photosynthesis. The fungi utilize the available sugars for its survival and in return, it supplies water and other types of nutrients such as minerals and ions, to the plant root system.

Note: The mycorrhiza association occurs between the fungi which derive the water and other important nutrients from the soil and transports it into the plant’s root system, which is taken up by the plant. In this type of association, the fungal hyphae either invades the cell membrane of the plant or remains extracellular. In a special type of endomycorrhiza such as the vesicular- arbuscular mycorrhizas (VAM), the hyphae absorb phosphate and supply it to the plant.