Vegetative propagation:
It is a method of asexual propagation. The vegetative method utilizes plant parts like leaves, stems, and roots for reproduction, either sourced from a single mother plant or other plants.
Importance of Vegetative Propagation:
When plants face challenges in regenerating through seeds, vegetative propagation becomes crucial for their revival. This approach offers benefits such as early growth, uniformity, and consistent traits compared to seed regeneration. The term “true to type” defines the reliability of vegetatively propagated populations. The use of propagation structures like playhouses, shade nets, greenhouses, mist houses, potting shades, tissue culture labs, and hardening rooms has significantly enhanced efficiency. Various growth media, such as nursery soil, finely ground farmyard manure, sphagnum moss, sand, sawdust, vermiculite, charcoal powder, peat moss, and coco peat, contribute to the successful commercial production of essential horticultural crops. In cases where multiple propagation methods are applicable, choosing the most effective and economical one becomes paramount.
Types:
1.Vegetativ e Reproduction through Underground Plant Parts:
- Roots: Plants like mint and ginger can reproduce vegetatively through their root systems. Nodes on the roots can develop into new shoots, enabling the plant to spread horizontally underground.
- Corms: Corms are swollen underground stems that store nutrients and allow plants like gladiolus and crocus to reproduce vegetatively. New corms develop from buds on the parent corm, creating offspring plants.
- Bulbs: Plants such as onions and tulips reproduce through bulbs. These underground storage organs contain buds that develop into new shoots and roots, facilitating vegetative propagation.
- Rhizomes: Rhizomes are horizontal underground stems that produce new shoots and roots at nodes along their length. Plants like bamboo and iris use rhizomes for vegetative reproduction, spreading laterally to form new plants.
2. Vegetative Reproduction using Above Ground Plant Parts:
- Buds: Some plants, like potatoes and strawberries, reproduce through buds. These can be adventitious buds on stems or specialized structures like tubers, which develop into new plants.
- Leaves: Certain plants, such as African violets and succulents, can reproduce vegetatively through their leaves. Leaves develop adventitious roots and shoots, allowing them to propagate and form new plants.
- Tissues: In tissue culture, small pieces of plant tissue, such as stem or leaf segments, are cultured in a nutrient medium to produce new plants. This method is commonly used in agriculture and horticulture for mass propagation of plants.
- Cuttings: Various types of cuttings can be used for vegetative propagation:
- Hardwood: Cuttings taken from mature, woody stems of deciduous plants during dormancy.
- Semi-hardwood: Cuttings taken from partially mature stems of plants that have completed their growth for the season.
- Softwood: Cuttings taken from young, green stems of actively growing plants.
- Herbaceous: Cuttings taken from non-woody, herbaceous plant parts such as stems or leaves.
- Layers: Plants like blackberries and roses can be propagated by layering, where a portion of a stem is bent to the ground and covered with soil. Roots develop at the buried portion, allowing the stem to establish itself as a new plant.
- Buds: Different types of buds can be used for vegetative propagation:
- Patch: A bud patch is a small piece of bark with an attached bud that is used for grafting onto rootstocks.
- Ring: A ring bud is a bud surrounded by a ring of bark that is removed from a stem and used for grafting.
- Forkert: Forkert buds are buds that develop at the base of a stem, often used for propagation in some fruit trees.
- “T” buds: “T” buds are buds that are inserted into a T-shaped incision in the bark of a rootstock for grafting.
- Grafting: Grafting is a technique where the tissues of one plant (the scion) are joined to the tissues of another plant (the rootstock), allowing them to grow together and function as a single plant. Different types of grafting include:
Limitations of Vegetative Propagation:
- Propagating plants like coconut and areca nut pose challenges due to their difficulty in vegetative propagation.
- Hybridization is not achievable in generations of plants propagated vegetatively.
- Skilled expertise and time investment are necessary for the successful vegetative propagation of plants.
Advantages:
- It ensures plants maintain true characteristics, displaying uniform growth, yield, and fruit quality.
- Exclusive vegetative propagation is essential for certain fruits like Banana, Pineapple, seedless Guava, and seedless Grape varieties.
- Fruit trees propagated vegetatively bear fruit earlier than their seed-propagated counterparts, with consistent genetic configurations.
- Asexually produced plants are manageable in size, featuring uniform fruits that simplify the harvesting process.
- Grafting onto resistant rootstocks, such as using ‘Rangpur Lime’ for budding Mandarin Orange, can prevent diseases in susceptible varieties.
- Conveniently combining better rootstocks with the method allows adaptation to specific climatic requirements.
- It enables the repair of damaged plant portions through techniques like bridge grafting or buttressing, aiding in wound healing caused by rodents.
- Improvement of inferior crown quality in existing plants, like in mangoes, is achievable through techniques such as side grafting and crown grafting.
- Growing multiple varieties on the same plant, such as Roses and Mangoes on different branches of the same stock, is feasible.
- Higher plant density per hectare is attainable due to small canopies and restricted growth.
- Modern techniques like tissue culture and micropropagation enhance rapid multiplication through vegetative propagation.
Disadvantages:
- Vegetative propagation can be challenging and more expensive for certain plants like papaya and coconut.
- Vegetative propagated plants may lack the vigor and longevity seen in plants, requiring specialized skills for successful propagation.
- Hybridization is not possible in these plants due to limited progeny variation, making them unsuitable for developing new varieties.
- Plants propagated asexually are less hardy and more susceptible to adverse conditions such as soil, climate, diseases, and pests.