Buds

Buds

Buds are the growing points surrounded by protective scale leaves. The bud primordium matures into bud. They have compressed axis in which the internodes are not elongated and the young leaves are closed and crowded. When these buds develop, the internodes elongate and the leaves spread out. Buds have architecture identical to the original shoot and develop into lateral branches or may terminate by developing into a flower or inflorescence. Based on Origin Buds are classified into (a) Terminal or Apical bud (b) Lateral or Axillary or Axil bud. Based on Function Buds classified into (a) Vegetative bud (b) Floral or Reproductive bud

1.        Terminal bud or apical bud: These buds are present at the apex of the main stem and at the tips of the branches.

2.        Lateral bud or Axillary bud: These buds occur in the axil of the leaves and develop into a branch or flower.

2.        Extra axillary bud : These buds are formed at nodes but outside the axil of the leaf as in Solanum americanum.

3.        Accessory bud : An extra bud on either side (collateral bud) or above (superposed bud or serial bud) the axillary bud. Example: Citrus and Duranta

4.        Adventitious buds: Buds arising at any part other than stem are known as adventitious bud. Radical buds are those that arises from the lateral roots which grow into plantlets. Example: Millingtonia, Bergera koenigii (Murraya koenigii), Coffea arabica and Aegle marmelos. Foliar buds are those that grow on leaves from veins or from margins of the leaves. Example: Begonia (Elephant ear plant) and Bryophyllum (Sprout leaf plant). Cauline buds arise directly from the stem either from cut, pruned ends or from branches. Adventitious buds function as propagules which are produced on the stem as tuberous structures. Example: Dioscorea, Agave.

5.        Bulbils (or specialized buds) : Bulbils are modified and enlarged bud, meant for propagation. When bulbils detach from parent plant and fall on the ground, they germinate into new plants and serve as a means of vegetative propagation. In Agave and Allium proliferum floral buds get modified into bulbils. In Lilium bulbiferum and Dioscorea bulbifera, the bulbils develop in axil of leaves. In Oxalis, they develop just above the swollen root.