Alargeproportionofmutantswithalteredpigmentfeatureshavebeenobtainedviaexposuretoheavy-ionbeams,atechniquethatisefficientfortraitimprovementinthebreedingofplantsandalgae.However,littleisknownaboutthechangesofthephotosyntheticresponseofmicroalgaeafterexposure.Inourgroup,sixprogeniesofScenedesmusquadricaudadeficientinchlorophyllawereisolatedaftercarbon-ionexposurethatwereprovidedbytheheavyionresearchfacilityinLanzhou(HIRFL),China.Twoprogenieswerepickedupbecausetheirphotosyntheticefficiencyandthephotoprotectionabilityweremarkedlydifferentfromthewildtype.