Propagation by specialized plant parts
i) Rhizome: It refers to the specialized stem structure in which the main axis of the plant grows
horizontally at or just below the ground level. e.g., Bamboos, ginger, turmeric.
ii) Offset: It refers to the special type of lateral shoots or branch which develops from the main stem in certain plants and is characterized by shortened and thickened stem. e.g., Date palm, pineapple.
iii) Sucker: Sucker refers to the shoots that arise from an adventious bud or roots of a plant at below ground. E. g., Dalbergia sissoo.
iv) Bulb: Bulb is a specialized underground organ consisting of a short, fleshy vertical stem axis bearing at its apex as a growing point. e.g., Onion, lily.
v) Corm: The swollen base of a stem axis enclosed by the dry, scale-like leaves is called as corm.
It is a solid stem structure with distinct nodes and internodes. e.g., Gladiolus, elephant yam.
vi) Tuber: It is a modified stem structure which develops below the ground as a result of swelling of the sub-apical portion of a stolen and subsequent accumulation of reserve materials. Eg, Potato, Jerusalem artichoke.
vi) Runner: Runner is a specialized stem which develops from the axis of the leaf at the crown of the plant. This grows horizontally along the ground. E.g., Mentha spp.
6) Micro propagation: Micro or in vitro propagation refers to the development of new plants from very small pieces of plants in an artificial medium under aseptic conditions.