1、Ex situ conservation of forest genetic resources: Principles and practices Ramanatha Rao,Genetic resourcesGenotypes or populations CultivarsGenetic stocks, & Related wild & weedy speciesConservation Species level Genepool level or Ecosystem level, 衬塑复合管 涂塑复合管 钢塑复合管 消防涂覆钢管 ,Ex Situ Conservati
2、on has to take into account,Biological factors of the species Breeding systems Production of seeds Nature of seeds Seed size and volume,Managing the FGR genebanks CollectingMonitoring storage conditionsViability monitoringRegeneration and multiplication,Characterization and evaluationDocumentation a
3、nd informationDistribution for use,Field genebanks (FGB)/Arboreta/Ex Situ stands Some problemsDamaged by natural calamities Infection Neglect or abuseSubstantial no. of individual genotypes Require more spaceRelatively expensive to maintain However Provide easy & ready access Alternative methods
4、 are yet to be developed Major role for perennial species,Conservation of Plants,Seed collection At least 150 trees if their relationship is unknownSeed should be collected from at least 25 randomly chosen and supposedly unrelated individualsAim for final stand size of 500-1500 individuals or more T
5、he different numbers are based on population genetic considerations,Conservation of Plants FGB (contd.),Important considerations Establishment of seedlings Sampling techniques Number of plants Security of siteReplication/duplication Adaptation Size of the plot Pests and diseases/natural calamities I
6、solation Ease of access,Conservation of Plants FGB (contd.),Conservation of Tissues/CellsDifficult-to-conserve speciesRecalcitrant seedsVegetatively propagatedLarge seeds For some species the only option Cryopreservation Rapid progress madeGreat potential for conservation In vitro conservation: secu
7、rity, availability & cost,For the longterm conservation of shoot cultures Cryopreservation in LN2 becoming availableOther roles Distribution of germplasm Collecting of samples from the fieldNeed to keep culture growth to Minimum or arrested,Conservation of Tissues/Cells (contd.),Ways to achieve
8、slow growthUse of immature zygotic embryos (not for vegetatively propagated species) Addition of inhibitors or retardants Manipulating storage temperature Mineral oil overlay Reduced oxygen tension Defoliation of shoots,Conservation of Tissues/Cells (contd.),Essential requirementsCapacity of plants
9、to regenerate in vitro Establish in the filed Genes for regeneration ability?,StatusProtocols for many species Work in progress on many others Work on somaclonal variation Genetic uniformity of the materialMuch research needed in Monitoring genetic stability & Ways & means of conserving GD t
10、hrough in vitro,Conservation of Tissues/Cells (contd.),Synthetic SeedsAnother promising method for Clonally propagated or Species with recalcitrant seedEncapsulation of shoottips & somatic embryos In semisolid material Beads'With current pace of development Production & storage of artifi
11、cial seeds may be a routine practice soon,Conservation of Tissues/Cells (contd.),In vitro genebanks Discussed only different components Need align all the components Protocols for tissue culture Successful regeneration Transfer to soil Genetic stability Cryopreservation of cultured material Vitrific
12、ation or encapsulation For viable long term conservation strategy,Conservation of Tissues/Cells (contd.),DNA or Gene Banks Progress in biotechnology Breaking down species barriers Progress in this field has led DNA libraries Single useful genes Suggestions to store in DNA libraries Total genomic inf
13、ormation of germplasm Despite the problems DNA Storage - an additional option for Improves the accessMay allow recovery of genes from extinct taxa,DNA Storage,National partners to spend some time to work out above steps for specific target genetic diversity /speciesDiscuss & develop process of ex situ conservation for target genetic diversity/species Identify resourcesFollow up as needed,Next steps (Contd.),
