File Name: advantages and disadvantages of micropropagation .zip
What is Plant Tissue Culture? Plant Tissue Culture is a process that uses plant material in a growing medium to grow new platelets. The initial plant material is cultured and developed in a specific and tightly controlled environment. Otherwise known as micropropagation, the Tissue Culture Process helps you to grow multiple uniform plants in quick succession. This process is beneficial for developing countries looking to increase crop yield, a private at-home grower interested in producing consistent quality, as well as businesses looking to produce exact replicas of a species for profit.
Plants can be propagated by sexual through generation of seeds or asexual through multiplication of vegetative parts means. Clonal propagation refers to the process of asexual reproduction by multiplication of genetically identical copies of individual plants. The term clone is used to represent a plant population derived from a single individual by asexual reproduction.
Asexual reproduction through multiplication of vegetative parts is the only method for the in vivo propagation of certain plants, as they do not produce viable seeds e. Clonal propagation has been successfully applied for the propagation of apple, potato, tuberous and several ornamental plants.
Faster multiplication — large number of plants can be produced from a single individual in a short period. Seed — raised plants pass through an undesirable juvenile phase which is avoided in asexual propagation. The in vivo clonal propagation of plants is tedious, expensive and frequently unsuccessful. In vitro clonal propagation through tissue culture is referred to as micro propagation. Use of tissue culture technique for micro propagation was first started by Morel for propagation of orchids, and is now applied to several plants.
Micro propagation is a handy technique for rapid multiplication of plants. Some authors add two more stages stage 0 and IV for more comprehensive representation of micro- propagation. All these stages are represented in Fig. This is the initial step in micro- propagation, and involves the selection and growth of stock plants for about 3 months under controlled conditions. In this stage, the initiation and establishment of culture in a suitable medium is achieved.
Selection of appropriate explants is important. The most commonly used explants are organs, shoot tips and axillary buds. The chosen explant is surface sterilized and washed before use. It is in this stage, the major activity of micro propagation occurs in a defined culture medium. Stage II mainly involves multiplication of shoots or rapid embryo formation from the explant. This stage involves the transfer of shoots to a medium for rapid development into shoots.
Sometimes, the shoots are directly planted in soil to develop roots. In vitro rooting of shoots is preferred while simultaneously handling a large number of species. This stage involves the establishment of plantlets in soil. This is done by transferring the plantlets of stage III from the laboratory to the environment of greenhouse. For some plant species, stage III is skipped, and un-rooted stage II shoots are planted in pots or in suitable compost mixture. The different stages described above for micro propagation are particularly useful for comparison between two or more plant systems, besides better understanding.
It may however, be noted that not all plant species need to be propagated in vitro through all the five stages referred above. Micro propagation mostly involves in vitro clonal propagation by two approaches:.
Besides the above two approaches, the plant regeneration processes namely organogenesis and somatic embryogenesis may also be treated as micro propagation.
Organogenesis: The formation of individual organs such as shoots, roots, directly from an explant lacking preformed meristem or from the callus and cell culture induced from the explant. Quiescent or actively dividing meristems are present at the axillary and apical shoots shoot tips. The axillary buds located in the axils of leaves are capable of developing into shoots.
In the in vivo state, however only a limited number of axillary meristems can form shoots. By means of induced in vitro multiplication in micro propagation, it is possible to develop plants from meristem and shoot tip cultures and from bud cultures.
Apical meristem is a dome of tissue located at the extreme tip of a shoot. The apical meristem along with the young leaf primordia constitutes the shoot apex. For the development of disease-free plants, meristem tips should be cultured. Meristem or shoot tip is isolated from a stem by a V-shaped cut. The size frequently 0. In general, the larger the explant shoot tip , the better are the chances for culture survival.
For good results of micro propagation, explants should be taken from the actively growing shoot tips, and the ideal timing is at the end of the plants dormancy period. A diagrammatic representation of shoot tip or meristem culture in micro propagation is given in Fig In stage I , the culture of meristem is established. In stage II , shoot development along with axillary shoot proliferation occurs. High levels of cytokinins are required for this purpose.
Stage III is associated with rooting of shoots and further growth of plantlet. The root formation is facilitated by low cytokinin and high auxin concentration. This is opposite to shoot formation since high level of cytokinins is required in stage II. Lower light intensity is more appropriate for good micro propagation. The plant buds possess quiescent or active meristems depending on the physiological state of the plant. Two types of bud cultures are used— single node culture and axillary bud culture.
This is a natural method for vegetative propagation of plants both in vivo and in vitro conditions. The bud found in the axil of leaf is comparable to the stem tip, for its ability in micro propagation. A bud along with a piece of stem is isolated and cultured to develop into a plantlet. Closed buds are used to reduce the chances of infections.
A diagrammatic representation of single node culture is depicted in Fig In single node culture, no cytokinin is added.
In this method, a shoot tip along with axillary bud is isolated. The cultures are carried out with high cytokinin concentration. As a result of this, apical dominance stops and axillary buds develop. A schematic representation of axillary bud culture for a rosette plant and an elongate plant is given in Fig This is however, variable and depends on the nature of the plant species and the developmental stage of the explant used.
In general, juvenile explants require less cytokinin compared to adult explants. Sometimes, the presence of apical meristem may interfere with axillary shoot development. In such a case, it has to be removed. The stem and leaf structures that are naturally formed on plant tissues located in sites other than the normal leaf axil regions are regarded as adventitious shoots. There are many adventitious shoots which include stems, bulbs, tubers and rhizomes.
The adventitious shoots are useful for in vivo and in vitro clonal propagation. The meristematic regions of adventitious shoots can be induced in a suitable medium to regenerate to plants. Organogenesis is the process of morphogenesis involving the formation of plant organs i. It is of two types — direct organogenesis and indirect organogenesis. Tissues from leaves, stems, roots and inflorescences can be directly cultured to produce plant organs.
In direct organogenesis, the tissue undergoes morphogenesis without going through a callus or suspension cell culture stage. The term direct adventitious organ formation is also used for direct organogenesis.
Induction of adventitious shoot formation directly on roots, leaves and various other organs of intact plants is a widely used method for plant propagation. This approach is particularly useful for herbaceous species. For appropriate organogenesis in culture system, exogenous addition of growth regulators—auxin and cytokinin is required. The concentration of the growth promoting substance depends on the age and nature of the explant, besides the growth conditions.
When the organogenesis occurs through callus or suspension cell culture formation, it is regarded as indirect organogenesis Fig Callus growth can be established from many explants leaves, roots, cotyledons, stems, flower petals etc.
The explants for good organogenesis should be mitotically active immature tissues. It is advantageous to select meristematic tissues shoot tip, leaf, and petiole for efficient indirect organogenesis. This is because their growth rate and survival rate are much better. For indirect organogenesis, the cultures may be grown in liquid medium or solid medium. The concentration of growth regulators in the medium is critical for organogenesis. By varying the concentrations of auxins and cytokinins, in vitro organogenesis can be manipulated:.
The process of regeneration of embryos from somatic cells, tissues or organs is regarded as somatic or asexual embryogenesis. Somatic embryogenesis may result in non-zygotic embryos or somatic embryos directly formed from somatic organs , parthogenetic embryos formed from unfertilized egg and androgenic embryos formed from male gametophyte. In a general usage, when the term somatic embryo is used it implies that it is formed from somatic tissues under in vitro conditions. Somatic embryos are structurally similar to zygotic sexually formed embryos, and they can be excised from the parent tissues and induced to germinate in tissue culture media.
Development of somatic embryos can be done in plant cultures using somatic cells, particularly epidermis, parenchymatous cells of petioles or secondary root phloem. Somatic embryos arise from single cells located within the clusters of meristematic cells in the callus or cell suspension. First a pro-embryo is formed which then develops into an embryo, and finally a plant.
When the somatic embryos develop directly on the excised plant explant without undergoing callus formation, it is referred to as direct somatic embryogenesis Fig This is possible due to the presence of pre-embryonic determined cells PEDQ found in certain tissues of plants. The characteristic features of direct somatic embryogenesis is avoiding the possibility of introducing somaclonal variations in the propagated plants.
In indirect embryogenesis, the cells from explant excised plant tissues are made to proliferate and form callus, from which cell suspension cultures can be raised. Certain cells referred to as induced embryo genic determined cells IEDC from the cell suspension can form somatic embryos.
The first method involving the meristems and induction of multiple shoots is the preferred method for the micropropagation industry since the risks of somaclonal variation genetic variation induced in tissue culture are minimal when compared to the other two methods. Living plant materials from the environment are naturally contaminated on their surfaces and sometimes interiors with microorganisms, so their surfaces are sterilized in chemical solutions usually alcohol and sodium or calcium hypochlorite. As shoots emerge from a culture, they may be sliced off and rooted with auxin to produce plantlets which, when mature, can be transferred to potting soil for further growth in the greenhouse as normal plants. Plant tissue culture is used widely in the plant sciences, forestry, and in horticulture. Plant tissue culture is a widely known technique for the production of large numbers of genetically identical plantlets. However, they are more easily removed from the explant by gentle rinsing, and the remainder usually can be killed by surface sterilization.
Commercial tissue culture involves exposing plant tissue to a specific regimen of nutrients, hormones, and light under sterile conditions to produce many new plants over a very short period of time. Tissue culture is a biotechnology used in cloning vegetatively propagated plants. In this method, the plant cell is isolated and cultured in an appropriate medium to reform the cell wall and callus. Save my name, email, and website in this browser for the next time I comment. In commercial settings, QTL mapping Learn how your comment data is processed. Solid media are prepared from liquid media with the addition of a gelling agent, usually purified agar.
Advantages and Disadvantages of micro propagation with respect to commercialization. Site news. BIC Advantages Disadvantages of micro propagation with Benefits of Biotechnology in horticulture. Advantages Disadvantages of micro propagation with respect to commercialization Advantages and Disadvantages of micro propagation with respect to commercialization Clonal mass propagation - extremely large numbers of plants can be produced. Rather than getting plants per year from an initial cutting in vegetative propagation, one can obtain more than 1,, plants per year from one initial explant through micropropagation.
Micropropagation is the practice of rapidly multiplying stock plant material to produce many 3 Advantages; 4 Disadvantages; 5 References. Notes Micropropagation has a number of advantages over traditional plant propagation techniques: The main Archived from the original (PDF) on ^ Maciej.
Micropropagation is the practice of rapidly multiplying stock plant material to produce many progeny plants, using modern plant tissue culture methods. Micropropagation also referred as tissue culture is used to multiply plants such as those that have been genetically modified or bred through conventional plant breeding methods. It is also used to provide a sufficient number of plantlets for planting from a stock plant which does not produce seeds, or does not respond well to vegetative reproduction. Cornell University botanist Frederick Campion Steward discovered and pioneered micropropagation and plant tissue culture in the late s and early s.
Biotech Articles. Publish Your Research Online. Article Summary: Plant tissue culture has enabled the production of multiples of plants through the use of plant parts, techniques and conditions. Plant tissue culture is used to produce clones of plant in a method called micopropagation. Plant tissue culture relies on the fact that many plant cells have the ability to regenerate into a whole plant in a process called totipotency.
Recent Advances in Plant in vitro Culture. Tissue culture is the in vitro aseptic culture of cells, tissues, organs or whole plant under controlled nutritional and environmental conditions [ 1 ] often to produce the clones of plants. The resultant clones are true-to type of the selected genotype.
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Advantages Disadvantages of micro propagation with respect to commercialization. Clonal mass propagation - extremely large numbers of plants can be produced. Culture is initialized from small parts of plants – so no need of much space: from 1 m2 space in culture room, - plants can be produced per year.