动物世界里的你争我斗.ppt

1、Ex situ conservation of forest genetic resources: Principles and practices Ramanatha RaoGenetic resources Genotypes or populations Cultivars Genetic stocks, & Related wild & weedy speciesConservation Species level Genepool level or Ecosystem level http:/ 衬塑复合管 涂塑复合管 钢塑复合管 消防涂覆钢管 http:/Ex Situ Conser

2、vation has to take into accountBiological factors of the speciesBreeding systemsProduction of seedsNature of seedsSeed size and volumeManaging the FGR genebanks Collecting Monitoring storage conditions Viability monitoring Regeneration and multiplication, Characterization and evaluation Documentatio

3、n and information Distribution for useField genebanks (FGB)/Arboreta/Ex Situ stands Some problems Damaged by natural calamities Infection Neglect or abuse Substantial no. of individual genotypes Require more space Relatively expensive to maintain However Provide easy & ready access Alternative metho

4、ds are yet to be developed Major role for perennial speciesConservation of PlantsSeed 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 considerationsConservation of Plants FGB (contd.)Important considerations Establishment of seedlings Sampling techniques Number of plants Security of site Replication/duplication Adaptation Size of the plot Pests and diseases/natural calamities Is

6、olation Ease of accessConservation of Plants FGB (contd.)Conservation of Tissues/Cells Difficult-to-conserve species Recalcitrant seeds Vegetatively propagated Large seeds For some species the only option Cryopreservation Rapid progress madeGreat potential for conservation In vitro conservation: sec

7、urity, availability & cost For the long term conservation of shoot cultures Cryopreservation in LN2 becoming availableOther rolesDistribution of germplasm Collecting of samples from the fieldNeed to keep culture growth to Minimum or arrestedConservation of Tissues/Cells (contd.)Ways to achieve slow

8、growthUse of immature zygotic embryos (not for vegetatively propagated species)Addition of inhibitors or retardantsManipulating storage temperatureMineral oil overlayReduced oxygen tensionDefoliation of shootsConservation of Tissues/Cells (contd.)Essential requirements Capacity of plants to regenera

9、te in vitro Establish in the filed Genes for regeneration ability?StatusProtocols for many speciesWork in progress on many othersWork on somaclonal variationGenetic uniformity of the materialMuch research needed in Monitoring genetic stability & Ways & means of conserving GD through in vitro Conserv

10、ation of Tissues/Cells (contd.)Synthetic SeedsSynthetic SeedsAnother promising method for Clonally propagated or Species with recalcitrant seedEncapsulation of shoot tips & somatic embryos In semi solid material BeadsWith current pace of development Production & storage of artificial seeds may be a

11、routine practice soon Conservation of Tissues/Cells (contd.)In vitro genebanksIn vitro genebanks Discussed only different components Need align all the components Protocols for tissue cultureSuccessful regenerationTransfer to soil Genetic stabilityCryopreservation of cultured material Vitrification

12、or encapsulation For viable long term conservation strategy Conservation of Tissues/Cells (contd.)DNA or Gene BanksDNA or Gene BanksProgress in biotechnology Breaking down species barriers Progress in this field has led DNA libraries Single useful genes Suggestions to store in DNA libraries Total ge

13、nomic information of germplasm Despite the problems DNA Storage - an additional option for Improves the access May 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 /species Discuss & develop process of ex situ conservation for target genetic diversity/species Identify resources Follow up as needed Next steps (Contd.)