| Summary: | Routineproductionoflargenumbersoftransgenicplantsisrequiredtofullyexploitadvancesincassavabiotechnologyandsupportdevelopmentofiprovedgermplasmfordeploymenttofarmers.Thisarticledescribesanimproved,high-efficiencytransformationprotocolforrecalcitrantcassavacultivarTME14preferredinAfrica.Factorsthatfavorproductionoffriableembryogeniccalli(FEC)werefoundtobeuseofDKWmedium,crushingoforganizedembryogenicstructures(OES)through1–2mmsizedmetalwiremesh,washingofcrushedOEStissuesandshortexposureoftyrosinetosomaticembryos;andtransformationefficiencywasenhancedbyuseoflowAgrobacteriumdensityduringco-cultivation,co-centrifugationofFECwithAgrobacterium,germinationofparamomycinresistantsomaticembryosonmediumcontainingBAPwithgradualincreaseinconcentrationandvariationsofthefrequenyofsubcultureofcotyledonary-stageembryosonshootelongationmedium.Byapplyingtheoptimizedparameters,FECwereproducedforcassavacultivarTME14andtransformedusingAgrobacteriumstrainLBA4404harboringthebinaryvectorpCAMBIA2301.About70–80independenttransgeniclinespermlsettledcellvolume(SCV)ofFECwereregeneratedonselectivemedium.HistochemicalGUSassaysconfirmedtheexpressionofgusAgeneintransformedcalli,somaticembryosandtransgenicplants.ThepresenceandintegrationofthegusAgenewereconfirmedbyPCRandSouthernblotanalysis,respectively.RT-PCRanalysisoftransgenicplantsconfirmedtheexpressionofgusAgene.Thisprotocoldemonstratessignificantlyenhancedtransformationefficiencyoverexistingcassavatransformationprotocolsandcouldbecomeapwerfultoolforfunctionalgenomicsandtransferringnewtraitsintocassava.
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