MODIFICATION OF ROOTS 17JULY 2024
MODIFICATION OF TAP ROOTS :
1.STORAGE ROOTS: These roots store food material and become swollen they are edible in nature The function of absorption of water and nutrient done by secondary roots. They assume various shapes based on that they are following types:
(a)Conical: When they become cone like Ex. Carrot
(b) Fusiform : They are spindle shaped Broad in the middle with both end narrow.Ex.Radish
(c)Napiform :Spherical in shape basal portion is swollen and apex is tapering .Ex. Turnip
(d)Tuberous: They are swollen but do not have a definite shape.Ex. Mirabilis jalapa
NODULATED ROOTS: The primary branches of the leguminous plants bear nodule like swellings due to the presence of a bacteria named Rhizobium ,this is a symbiotic relationship between plant and bacteria. Plant provide food and shelter to the bacteria & in return bacteria fix atmospheric nitrogen and provide it to the plant.Ex.All leguminous plants like Pea, Dalbergia, etc.
PNEUMATOPHORES OR RESPIRATORY ROOTS:
In mangroves or saline swamps near sea shores the aeration is impossible hence the plants grown in such areas develop upright aerial braches from horizontal roots such upright branches are called pneumatophores which bear pores called lenticels for exchange of gases.Ex Sonneratia.
Modification of adventitious roots:
1.Storage roots : The adventitious roots that store food material.
(a)Tuberous roots: Arises from nodes of running stem also have adventitious bud they are swollen without a definite shape.Ex Sweet potato
(b) Fasciculated roots: Swollen tuberous roots in cluster .Ex. Dahlia
(c) Palmate tuberous roots : Swollen roots are palmate in shape (shape of human hand) Ex. Orchid
(d)Nodulose Roots: Swollen single bead at the apex. Ex. Mango ginger
(e)Moniliform roots: These roots are alternately swollen giving a beaded appearance.Ex. Bitter gourd
(d) Annulated roots : These thickened roots look as it formed by number of disc placed one above the other.Ex Ipecac
