This file is licensed under the creative commons attributionshare alike 4. Meristem micropropagation of cassava manihot esculenta. Somaclonal variations and their applications in horticultural. Somaclonal variation resulted from tissue or cell culture larkin and scowcroft, 1981 is an alternative source of new genetic diversity that is very useful for plant breeding programs including generating a novel character like drought tolerance. Variations in number and structure of chromosomes are commonly observed. Assessment of somaclonal variation in regenerated plants from immature embryos culture of durum wheat. Studies on induction of somaclonal variation in sugarcane saccharum officinarum and validation of mutant using molecular markers 10. Somaclonal variation is the genetic variation that is observed when plants are regenerated. Heritable somaclonal variation in wheat, tag theoretical and.
During the micropropagation of valuable elite clones, this variation usually results in offtypes that reduce the commercial value of resultant plants. Somaclonal variation was claimed to be a source of variation for crop improvement, especially for crops reproduced vegetatively larkin and scowcroft, 1981. The remaining content for 1973 will be released as soon as the issues become available to jstor. Somaclonal variation for disease resistance in wheat and. Applications of somaclonal variation somaclonal variation in crop improvement somaclonal variation in improvement of ornamental plants new variant retaining all the favourable characters along with an additional useful trait development of elite germplasm and commercial cultivars enhancing alien gene introgression into cultivated species in. Somaclonal variation for disease resistance in wheat 619 loids is wheat cultivar dependent. The economic consequence of somaclonal variation among. Extensive somaclonal variation for morphological and biochemical traits was observed among 142 regenerants of a mexican breeding. Progeny of 66 plants regenerated from callus cultures derived from immature embryos of norstar winter wheat were evaluated as seedlings for tolerance to controlled freezing. There is great interest in the phenotypic, genetic and epigenetic changes associated with plant in vitro culture known as somaclonal variation. In continuation of somaclonal variation and crop improvement i 1990, this volume is comprised of twentyfour chapters dealing with somaclonal variants showing resistance to saltdrought, herbicides.
Induced somaclonal variation has a potential for use in breeding programs as an additional source of variability. Somaclonal variation in a population of winter wheat sciencedirect. Somaclonal variation for disease resistance in wheat 619 loids is wheatcultivar dependent. Similarly, genetically transformed cells are carefully screened to avoid unwanted and unintended somaclonal variations so that the commercially released clones have only beneficial effects. Variation in plant phenotype is determined by genetic and epigenetic factors. The plants derived from such cells are referred to somaclones. Somaclonal variations have largely contributed towards the development of disease resistance in many crops e. Heritable somaclonal variation in gliadin proteins of wheat. Somaclonal variation in crop improvement i professor dr. Chromosomal rearrangements are an important source of this variation.
Keeping the type of somaclonal variation in cereal crops were low and undesirable. Combination of somaclonal variation and mutagenesis for. The term somaclonal variation is a phenomenon of broad taxonomic occurrence, reported for species of different ploidy levels, and for outcrossing and inbreeding, vegetatively and seed propagated, and cultivated and non. These variations will allow to introduce new characteristics into all major plant varieties thereby developing new improved varieties in a shorter period of time. Both scientists and science fiction writers envisioned that cloningthe production of many organisms from a single cell grown is tissue culture would produce row upon row of. As a result of somaclonal variations, several novel variants of existing crops have been developed, e. Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. May 05, 20 advantages of somaclonal variations help in crop improvement creation of additional genetic varitions increased and improved production ofsecondary metabolites selection of plants resistant to varioustoxins, herbicides, high salt concentrationand mineral toxicity suitable for breeding of tree species.
This file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. Somaclonal variation in tissue culture of triticum aestivum. Efficient tissue culture and regeneration methods were established using immature wheat embryos as expiants. Jamilah syafawati yaacob, rosna mat taha, norizam jaafar, zuliana hasni, hashimah elias, normadiha mohamed institute of biological sciences, faculty of science, university of malaya, 50603 kuala lumpur, malaysia. Somaclonal variation derived from in vitro culture is a novel source of germplasm. Somaclonal variation in crop improvement ii download.
Tissue culture increases the efficiency of mutagenic treatment to induce variations. Or the other hand, success in improving wheat plants by inducing somaclonal stuales sn. Study of somaclonal variation in two rice cultivars. Applications of somaclonal variations biology discussion. Somaclonal variation in crop improvement ii download ebook. Genotype differences in culturability were evident, and from the ten accessions most amenable to culture, a total of 2,846 plants were regenerated. Selected crops somaclonal variants, with increased disease resistance developed, without in vitro selection and within vitro selection are respectively given in tables 46. Read this article to learn about the basis, isolation and limitations of somaclonal variations and also factors affecting the production of somaclonal variants. Molecular characterization of genetic variation in. Callus induction, plant regeneration and somaclonal. Angra 2 1 instituto agronomico do paranaiapar, caixa postal 481, 8600970 londrina, pr, brasil.
The moving wall represents the time period between the last issue available in jstor and the most recently published issue of a journal. Plants regenerated from the embryogenic calli of wheat have revealed variants for various agronomic and quality characters such as plant height, stem thickness, leaf size, spike. Heritable somaclonal variation in gliadin proteins of. As this variation represents a new tool for the plant breeder. Heritable somaclonal variation in wheat springerlink. Somaclonal variation in tissue culture is a complex problem that needs several approaches to be appreciated correctly. The crops include rice, wheat, maize, sugarcane, potato, carrot etc. Mutationbased plant improvement, which changes one or a few specific traits of a cultivar, can contribute to crop improvement. Extensive somaclonal variation for morphological and biochemical traits was observed among 142 regenerants of a mexican breeding line. Development of somaclonal variants of wheat triticum. Highly differentiated tissues such as roots, leaves, and stems generally produce more variations than explants with preexisting meristems, such as axillary buds and shoot tips duncan 1997.
Somaclonal variation provides a valuable source of genetic variation for the. Somaclonal variation is a tool that can be used by plant breeders. Lt50 values predicted temperatures at which mean survival frequencies are 50% for four families in the r2 generation. Heritable somaclonal variation in gliadin proteins of wheat plants derived from immature embryo callus culture d. Genomic changes associated with somaclonal variation in. Some new strains of wheat, carrot, tomato, celery and other crops created via somaclonal variation are already undergoing field tests. Conclusion somaclonal variations being used as a novel source of heritable genetic variations suitable for upgrading existing cultivars of crop plants.
This variation arising from cell and tissue cultures is called somaclonal variation that can be geneticepigenetic in nature. Various references have introduced somaclonal variation as. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. Somaclonal variation caused by the process of tissue culture is also called tissue culture induced variation to more speci. Heritable somaclonal variation in wheat efficient tissue culture and regeneration methods were established using immature wheat embryos as explants. Somaclonal variation for freezing tolerance in a population.
The main factors that influence the variation generated from tissue culture are 1 the degree of departure from organised growth, 2 the genotype, 3 growth regulators and 4 tissue source. Production of haploid wheat plants and subsequent production of dihaploids double hap loids can fix desirable characters in a single generation. Epigenetic aspects of somaclonal variation in plants. Feb, 2016 a number of cultivars have been developed through somaclonal variation in different horticultural crops for a range of useful traits, which are presented in table 3.
The tech niques are more simple than those of recombinant dna, and they result in a rich source of genetic vari ability. Breeders are finding it attractive because of its simplicity. Tissue culturederived variation in crop improvement pdf. Quantification of the tissueculture induced variation in. Pdf thirtyone somaclones in two advanced successive selfed generations r 6 and r 7 regenerated in vitro from immature. Potential application of somaclonal variation in crops has been proposed as a supplementary tool to well established breeding approaches ahloowalia, 1982, cheng et al. Simultaneously, the effects of two concentrations of 2,4d 0. Study of somaclonal variation in two rice cultivars regenerated from embryo culture, using ssr markers hamed salehian 1, nadali babaeian 1, nadali bagheri 1, behnam sedaghati 2, farzad banaeiasl 3, sara kabirnataj 1 1department of plant breeding and biotechnology, sari agricultural sciences and natural university, iran.
Variation is understood to be generated via a combination of genetic andor. Studies on plant regeneration and somaclonal variation in wheat. Genomic changes associated with somaclonal variation. Iurure applications in the next five years, somaclonal variation should become widely used for crop improvement. Jones 3 1 kansas state university, department of agronomy, manhattan, ks 66506, usa. Among the factors that affect this socalled tissue culture induced variation are explant genotype, explant tissue origin, medium composition, and the length of time in culture. Introduction plant tissue culture is a source of new genetic variability, named as somaclonal variation larkin, scowcroft, 1981.
The use of only one type of molecular marker, such as rapds, to assess the genetic stability of an in vitro production system may be inadequate, and an approach that focuses on morphological traits appears to be a valuable. Somaclonal variation for disease resistance in wheat and production of dihaploids through wheat x maize hybrids. Identifying business opportunities and problems pdf download. Advantages of somaclonal variations help in crop improvement creation of additional genetic varitions increased and improved production ofsecondary metabolites selection of plants resistant to varioustoxins, herbicides, high salt concentrationand mineral toxicity suitable for. For example, tvtc is the somaclone with tangerine fruit color and virescent leaves. When plant tissue is passaged through in vitro culture, many regenerated plants appear to be no longer clonal copies of their donor genotype. Lt50 values predicted temperatures at which mean survival frequencies are 50% for four families in the r2. Combination of somaclonal variation and mutagenesis for crop. Several works with wheat have revealed that the somaclonal variation might result from point. Molecular characterization of genetic variation in somaclones. Selection of mineral toxicities tolerant in sorghum plant mainly for aluminium toxicity detection and isolation of somaclonal variants advantages of somaclonal variations help in crop improvement creation of additional genetic varitions increased and improved production of secondary metabolites selection of plants resistant to various toxins. Agronomic characteristics were studied in an r2 plant population, derived by self pollination from seventy regenerant plants r1, derived from immature. Somaclonal variation as a tool for crop improvement. Pdf somaclonal variation as a tool for crop improvement.
Somaclonal variation in tissue culture of triticum. Pdf somaclones, regenerated from three durum wheat cultivars karim, sebou and. The occurrence of somaclonal variation is both a boon and bane. Pdf somaclonal variation in bread wheat triticum aestivum l. In 1984, taiwan banana research institute started a selection program for resistance to fusarium wilt in cavendish bananas using somaclonal variation hwang and ko, 1987.
Ahloowalia bs 1982 plant regeneration from callus in wheat. Recently a somaclonal variant wheat variety hezu8 has been officially released for commercial production gao et al. Because there is a chance of result of unwanted offtypes that reduces the commercial value. Ahloowalia bs 1986 limitation to the use of somaclonal variation in crop improvement. Click download or read online button to get somaclonal variation in crop improvement ii book now. Studies on plant regeneration and somaclonal variation in.
Differences in both the frequency and nature of somaclonal variation may occur when regeneration is achieved from different tissue sources sahijram et al. Heritable, genetic changes alter the dna stable, but nonheritable changes alter gene expression, aka epigenetic since. The genetic variations found in the in vitro cultured cells are collectively referred to as somaclonal variations. In vitro propagation systems that are based on the use of microcuttings or meristem cultures are considered analogous to clonal cuttings and so widely viewed to be largely free from such somaclonal effects. Download book pdf somaclonal variations and crop improvement pp 1275 cite as. In a previous experiment, in vitro plants of three genotypes of. Genotype differences in culturability were evident, and from the ten accessions most amenable to culture, a total o f 2,846 plants were regenerated. The journal publishes original papers presenting new scientific results on breeding, genetics, physiology, pathology and production of primarily wheat, rye, barley, oat and maize. Somaclonal variation does not preclude the use of rice. Table 3 in vitro selection of desirable traits and development of some commercially exploited varieties through somaclonal variation in different horticultural crops. This site is like a library, use search box in the widget to get ebook that you want. Heritable somaclonal variation in wheat, tag theoretical.
Somaclonal variation can be manifested as either somatically or meiotically stable events. Genetic variations in plants that have been produced by plant tissue culture and can be detected as genetic or phenotypic traits. Callus induction, plant regeneration and somaclonal variation in in vivo and in vitro grown white shrimp plant justicia betonica linn. Multiple variants with the same phenotype are labeled tcl, tc2, tc3, etc. In addition, somaclonal variation has been free of the regulatory hurdles that plague products of recombinant dna. Somaclonal variation in the gliadin patterns of grains of regenerated wheat plants. Phenotypic and dna variation among putative plant clones is termed somaclonal variation. Agropyron desertorum f 1 hybrid somaclonal variation in tissue culture of triticum aestivum. The term somaclonal variation is a phenomenon of broad taxonomic occurrence, reported for species of different ploidy levels, and for outcrossing and inbreeding, vegetatively. Combination of somaclonal variation and mutagenesis for crop improvement. Heritable somaclonal variation in gliadin proteins of wheat plants.
160 1093 1318 1139 1115 443 967 133 160 975 454 986 1471 724 470 70 771 1489 747 1373 358 62 1405 1576 417 151 1540 1116 1253 1420 328 764 1403 31 1314 955 241 1354