Any means by which a plant reproduces itself without forming seeds or spores. In single-celled algae and fungi, it is achieved by simple cell division. Many bryophytes produce detachable buds called gemmae. Higher plants, especially flowering plants, may increase by a variety of means, such as bulbils, tubers, stolons, and runners. Fragments of stems or roots may break off and grow into new plants, as in many perennial weeds. Some plants, including fern species, bud off small plantlets along the edges of their leaves or in the leaf axils, a process called vivipary. Some species (eg blackberries) reproduce entirely in one or more of these ways, never producing viable seeds; All new plants produced by these means are clones, ie with a genetic make-up identical to that of the parent. A successful plant can thus produce offspring equally well-adapted to similar conditions. The process is also used in horticulture, allowing mass production of plants with desirable traits which might be lost in breeding.
Vegetative reproduction is a type of asexual reproduction found in plants also called vegetative propagation or vegetative multiplication. It is a process by which new plant "individuals" arise or are obtained without production of seeds or spores. It is both a natural process in many plant species (including organisms that may or may not be considered "plants", such as bacteria and fungi) and one utilized or encouraged by horticulturists to obtain quantities of economically valuable plants.
Natural vegetative reproduction is mostly a process found in herbaceous and woody perennials, and typically involves structural modifications of the stem, although any horizontal, underground part of a plant (whether stem or a root) can contribute to vegetative reproduction of a plant. Most plant species that survive and significantly expand by vegetative reproduction would be perennial almost by definition, since specialized organs of vegetative reproduction, like seeds of annuals, serve to survive seasonally harsh conditions. A plant that persists in a location through vegetative reproduction of individuals over a long period of time constitutes a clonal colony. However, in vegetative reproduction, the new plants that result are new individuals in almost every respect except genetic.
Natural vegetative structures
A rhizome is a modified stem serving as an organ of vegetative reproduction. Prostrate aerial stems, called runners or stolons are important vegetative reproduction organs in some species, such as the strawberry, numerous grasses, and some ferns. Adventitious buds develop into above ground stems and leaves, forming on roots near the ground surface and on damaged stems (as on the stumps of cut trees).
A form of budding called suckering is the reproduction or regeneration of a plant by shoots that arise from an existing root system.
Another type of a vegetative reproduction is the production of bulbs. Plants like onion (Allium cepa), hyacinth (Hyacinth), narcissus (Narcissus) and tulips (Tulipa) reproduce by forming bulbs. However, there are several cases where vegetatively propagated plants are not genetically identical. Leaf cutting propagation of certain chimeral variegated plants, such as snake plant, will produce mainly nonvariegated plants. The leafy crown of a pineapple fruit will root to form a new plant. Vegetative reproduction involves only vegetative structures, i.e.
Horticultural aspects
Man-made methods of vegetative reproduction are usually enhancements of natural processes, but range from simple cloning such as rooting of cuttings to grafting and artificial propagation by laboratory tissue cloning.
In horticulture, a "cutting" is a branch that has been cut off from a mother plant below an internode and then rooted, often with the help of a rooting liquid or powder containing hormones. When a full root has formed and leaves begin to sprout anew, the clone is a self-sufficient plant, genetically identical to the mother plant. Examples are cutting from the stems of blackberries (Rubus occidentalis), cutting from leaves of African violets (Saintpaulia), and cutting the stems of verbenas (Verbena) to create new plants. This is a process of taking a bud and grafting onto a plants stem.
Cultivated plants propagated by vegetative methods
A number of commonly cultivated plants are propagated by vegetative means rather than by seeds. This is a listing of such plants:
Avocado Banana Cacao Canna Citrus (lemon, orange, grapefruit) Date Fig Manioc (cassava) Nut crops (walnut, pecan) Pineapple Pome fruits (apple, pear) Poplar Potato Strawberry Sugar cane Tea Vanilla Willow
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