Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Application of tissue culture in crop improvement


Published on

innovative ideas of tissue culture in crop improvement

Published in: Education
  • Be the first to comment

Application of tissue culture in crop improvement

  1. 1. Application of tissue culture in crop improvement Presented by, M. Uma Maheshwari, M. Phil., (Botany)
  2. 2. Introduction  Plant tissue culture comprises a set of invitro techniques, methods, strategies that are part of plant biotechnology.  Tissue culture had been exploited to create genetic variability, to improve the health of planted material, increase the number of desired germplasms.  Tissue culture are combined with molecular techniques, successfully used toincorporatespecifictraitsthroughgenetransfer.  Thecultureofprotoplasts,anthers,microspores,ovulesandembryos used tocreatenewgeneticvariation.  Cell culture produced somaclonal and gametoclonal variants with crop improvementpotential.  The culture of single cells and meristems can be effectively used to eradicatepathogenstherebyincreasingtheyieldofthecrops.
  3. 3. Application of tissue culture in crop improvement Newer molecular and cellular technologies have a broad significant impactoncropimprovement The various application of tissue culture approaches to crop improvement are- Breedingandbiotechnology Widehybridization Haploids Somaclonalvariation Micropropagation Syntheticseeds Pathogeneradication Germplasmpreservation
  4. 4. Breeding and biotechnology Plantbreedingseparatedintotwoactivities  Manipulatinggene  Plantevaluation Controlled pollination of plants lead to specific crosses result in new generation performedbetterintheyield Tissue–culture techniques is having significant impact in manipulating genetic diversity More than 50 different species have already been genetically modified either by vector dependent (Agrobacterium) or vector independent (Biolistic, micro- injectionandliposome)methods Tissue culture techniques have been played a major role in the development of plantgeneticengineering,especiallyinefficientgenetransferandtransgenicplant recovery
  5. 5. Wide hybridization Acriticalrequirementforcropimprovementistheintroductionofnew geneticmaterialintothecultivatedlinesofinterest,whetherviasingle genes, throughgeneticengineeringormultiplegenesthroughconventional hybridizationortissueculturetechniques Theprocessoffertilizationcanbeblockedatanyofthestages,resultingin thefunctionalbarriertothehybridizationandtheblockageofgenetransfer betweenthetwoplants. Twotypesof barriers Pre-zygoticbarriers Post-zygoticbarriers Toovercometheseproblems,thefollowingproceduresarefollowed invitrofertilization Embryoculture Protoplastfusion
  6. 6. in vitro fertilization  IVF has been used to facilitate both interspecific and intergeneric crosses, to overcome physiological basedselfcompatibilityandtoproducehybrids Awiderangeofplantshavebeenrecovered suchas  Tobacco  Clover  Corn  Rice  Canola  Cotton  Poppy
  7. 7. Embryo culture Itdealswiththesterileisolationandinvitrogrowthofamatureoranimmatureembryo ofobtainingaviableplant Seeddormancycanbesuccessfullybyepassed Twotypesofembryoculture Matureembryoculture Immatureembryoculture/Embryorescue Matureembryoculture o Matureembryosareisolatedfromripeseedsandare culturedin vitro o Itiscarriedoutduringfollowingcondition o Embryosremaindormantforlongtime o Lowsurvivalofembryosinvivo o Toavoidinhibitioninseedgermination o Convertsterileseedsintoviableseedlings
  8. 8. Embryo culture
  9. 9. It has been successfully applied to a number of agricultural crops including cotton, barley, banana, orchids, roses, tomato, rice, jute and some brassicas Application of embryo culture o Prevention of embryo abortion o Overcoming seed dormancy o Shortening of breeding cycle o Production of haploids o Overcoming seed sterility o Clonal propagation Embryo rescue o It involves the culture of immature embryos to rescue them from unripe or hybrid seeds that fails to germinate
  10. 10. Protoplast fusion It has been suggested as a means of developing unique hybrid plantswhichcannotbeproducedbyconventionalhybridization Protoplasts of two plants can be fused by chemical or physical methods Applicationofprotoplastfusion Ithas opened new possibilities for thein vitro genetic manipulation oftoimprovethecrops  Diseaseresistance  Environmentaltolerance  Qualitycharacters Cytoplasmicmalesterility
  11. 11. Protoplast fusion
  12. 12. Haploids  Haploid plants are characterized by possessing only a single set of chromosomes.  Haploid plants are of great significance for the production of homozygous lines  At least 171 plant species have been used to produce haploid plants by pollen,antherandmicrosporeculture  Cereals(barley,maize,rice,rye,wheat)  Fruits(grapeandstrawberry)  Oil-seeds(rapeandcanola)  Trees(apple,litchi,poplarandrubber)  Plantationcrops(cotton,sugarcaneandtobacco)  Vegetable crops (asparagus, Brussels sprouts, cabbage, carrot, pepper,potato,sugarbeet,tomatoandwingbean)
  13. 13. Haploids
  14. 14. Androgenesis  Haploidproductionoccurs throughantherorpollen culture  Intheplantbiotechnologyprogramme,haploidproductionisachievedby twomethods  Androgenesis  Gynogenesis Gynogenesis  Haploidproductionoccurs throughovaryorovule culture Pollenculturepreferablethanantherculturebecause • Androgenesis,startingfromasinglecellcanberegulated • Isolated micro spores are ideal for several genetic manipulations (transformation,mutagenesis) • Theyieldof haploidplantsisrelativelyhigher • Undesirableeffectofantherwallandassociatedtissuescanbeavoided
  15. 15. Somaclonal variation  The genetic variations found in the in vitro cultured cells are collectively calledsomaclonalvariations.Theplantsarecalledsomaclones  Itoccursduetogeneticheterogeneityinplanttissuecultures  Expressionofgeneticdisorders  Spontaneousmutationduetocultureconditions The geneticchangesinclude  Polyploidy  Aneuploidy  Chromosomal breakage  Deletion  Translocations  Geneamplification  Severalmutations
  16. 16.  Many of the changes observed in plants are regenerated in vitro have potential agriculturalandhorticulturalsignificance  Thealterationsinclude  Plantpigmentation  Seedyield  PlantvigourandSize  Essentialoils  Leafandflowermorphology  Fruitsolids  Diseasetoleranceorresistance Such variations are observed in wheat, maize, tomato, sugarcane,oats,oilseedrape,celery,potato
  17. 17. Somaclonal variation
  18. 18. Micro propagation invitroclonalpropagationthroughtissuecultureis calledmicropropagation Themicropropagationtechniqueispreferredto conventionalasexualpropagation Smallamountoftissueisneeded Possiblealternativefordevelopingresistance Meansforinternationalexchangeofplant materials invitrostockcanbeeasilyproliferated Micropropagationinvolvesinvitroclonalpropagationbytwo approaches  Multiplicationbyaxillarybuds/apicalbuds Multiplicationbyadventitiousroots
  19. 19. • Selection of mother plant and its maintenanceStage 0 • Initiation and establishment of cultureStage 1 • Multiplication of shoots or rapid somatic embryo formationStage 2 • in vitro germination of somatic embryos and or rooting of shootsStage 3 • Transfer of plantlets to sterilized soil for hardening under green house condition Stage 4 Major stages involved in Micro propagation
  20. 20. Micro propagation Applications  High rate of plant propagation  Production of disease-free plants  Production of seeds in some crops  Cost-effective process  Automated micro propagation Disadvantages x Contamination of cultures x Brewing of medium x Genetic variability x Vitrification x Cost factor
  21. 21. Synthetic seeds Usually, Sodium or Calcium alginate is selected for encapsulation becauseitislesstoxictoembryosandeasytohandle The artificial seeds can be maintained in a viable state still they are planted Asynthetic or artificial seed has been defined as a somatic embryo encapsulatedinsideacoatingandisconsideredtobeanalogoustoa zygoticseed Differenttypesofsyntheticseedsare Somaticembryosencapsulatedinawatergel Dried andcoatedsomaticembryos Driedanduncoatedsomaticembryos Somaticembryosuspendedinafluidcarrier Shootbudsencapsulatedinawatergel
  22. 22. Pathogen eradication Plant species are infected with pathogens-viruses, bacteria, fungi, mycoplasma and nematodesthatcausesdiseases Tissue culture techniques employing meristem-tips are successfully used for the productionofdisease-freeplants List of plants with virus-elimination by meristem-culture Plant species Virus eliminated Solanum tuberosum Leaf roll potato virus-A, X, Y, S Allium sativum Mosaic virus Petunia spp. Tobacco mosaic virus Musa spp. Cucumber mosaic virus Brassica oleracea Cauliflower / turnip mosaic virus Armoracia rusticena Turnip mosaic virus
  23. 23. Germplasm preservation Germplasm broadly refers to the hereditary material transmittedtotheoffspringthroughgermcells The main objective of germplasm conservation is to preserve the genetic diversity of a particular plant or geneticstockforitsuseatanytimeinfuture in vitro methods employing shoots, meristems and embryosareideallysuitedforgermplasmconservation Threemainapproaches  Cryopreservation  Coldstorage  Low-pressure and Low-oxygen storage
  24. 24. Advantages  Largequantitiescanbestoredinasmallarea Maintained in an environment free from pathogens Protectedagainstnature’shazards From germplasm stock, large number of plantscanbeobtainedwheneveritisneeded Obstacles for their transport through national and international borders are minimal (since theyaremaintainedunderasepticcondition)