SUM M.A RYBulbil formation in vitro by single leaf explants from shoot clump cultures was investi^iiied for Sarctssus cultivars ftt Kfverne and Ilaweva. Smgie leaf explants (30 50 mm leaf with attached basal plate tissue) formed bulbils very mfrequently unless cultured on media containing both auxin and a high concentration of sucrose wbereas auxin was not necessary for bulbil formation by sboot clump cultures. As well as showing mucb stronger stimulation by auxin, bulbil initiation and development were more stronglv inhibited by BA in single leaf cultures than in shoot clump cultures. Partitioning of dry matter into bulbils was generally lower in single leaf cultures tban in shoot clump cultures but was more sensitive to growth regulators.Optimal sucrose and auxin concentrations for bulbil development b> single leaf cultures were investigated. Bulbil formation in the presence of NAA was strongly stimulated bv 176 mM sucrose for both cultivars but ibere w^ere genotypic differences m auxin responses. St Keverne showing good bulbil dex elopment witb 054 //M NAA, 5-4//M IAA and 5-4 ^/M lBA and Hawera responding only to 27/'M IA.A.It is concluded tbat single leaf cuhures could provide a simple system for investigation of the regulation i>f Narcissus bulb initiation and development.