Embryogenic Protoplast Cultures of Orange Jessamine (Murraya Paniculata) and Their Regeneration Into Plants Flowering in Vitro

Embryogenic callus was induced from the hypocotyl region of seedlings germinated from immature embryos of orange jessamine (Murraya paniculata (L.) Jack) on Murashige & Tucker (1969) medium containing 50 g 1-1 sucrose, 5.0 mg 1- l benzyladenine, 2.5 mg 1-1 2,4-dichlorophenoxyacetic acid and 600 mg 1-1 malt extract. Isolated protoplasts divided to produce callus on Murashige & Tucker (1969) medium containing 50 g 1-1 sucrose, 0.01 mg 1-1 gibberellin A4+7 and 600 mg 1-l malt extract. Callus developed to plantlets via somatic embryogenesis on Murashige & Tucker (1969) medium with 50 g 1 -l lactose but no plant growth regulators. These plantlets flowered in vitro on half strength Murashige & Tucker (1969) medium containing 50 g 1-l sucrose after 2 months culture

In vitro flowering of Fortunella hindsii (Champ.)

Abstract. Branch internodes of mature plants and stem internodes of seedlings of Fortunella hindsii flowered in vitro on half-strength MT (Murashige and Tucker 1969) basal medium supplemented with benzyladenine, adenine, 6-~-~dimethylallylaminopurine and kinetin. The highest percentage of flowering was achieved with explants ori- ginating from branch internodes of flowering plants close to the apex on half-strength MT basal medium containing 5% sucrose and 0.01 mg 1-1 BA in light. Exposure to darkness for more than 3 weeks followed by re-exposure to light reduced flowering. Flowering required a 4-day exposure to BA, but shoot formation could be initiated even without exposure to BA. First branch internode segments on MT basal medium containing 5% sucrose were prolific in flower (85%) production. The sucrose treatment affected the flower bud size distribution. There were about 13 flower buds per culture in the largest size category (>5 ram)

Plant Regeneration Via Somatic Embryogenesis From Protoplasts Of Uganda Cherry Orange (Citropsis Schweinfurthii)

Protoplasts isolated from embryogenic callus of Citropsis schweinfurthii (Engl.) Swing. & M. Kell were cultured in MT (Murashige and Tucker 1969) basal medium containing 5% sucrose supplemented with 0.0, 0.001, 0.01, 0.1 or 1.0 mg 1-1 BA, 0, 300, 600 or 900 mg 1-1 malt extract and 0.6 M sorbitol. The highest plating efficiency was obtained on MT basal medium containing 5% sucrose supplemented with 0.01 mg 1-1 BA and 600 mg 1-1 malt extract. MT basal medium containing 5% sucrose and supplemented with 0.01 mg 1-1 kinetin was found to be a medium suitable for the development of globular somatic embryos derived from protoplasts into heart-shaped somatic embryos with cotyledon-like struc- tures. The highest percentage of shoot formation was obtained using 0.1 mg 1-1 GA 3. A complete protoplast- to-plant system was developed for C. schweinfurthii, which could facilitate the transfer of nuclear and cyto- plasmic genes from this species into cultivated Citrus through protoplast fusion

Plant Regeneration Via somatic Embryogenesis from Protoplasts of Six Plant Species Related to Citrus

Protoplasts isolated from embryogenic callus of Fortunella polyandra (Ridl.), Atalantia bilocularis (Pieree ex Guill.), Hesperethusa crenulata (Roxb.), Glycosmis pentaphylla (Re~.) Ca)rr., Triphasia trifolia (Burm. f.) P. Wils. and Murraya koenigii (L.) Spreng. were cultured in MT (Murashige and Tucker 1969) basal medium contain- ing 5% sucrose supplemented with 0.0, 0.001, 0.01, 0.1 or 1.0 mg 1-1 BA and 0.6 M sorbitol. The highest plating efficiencies for all species were obtained on MT basal medium containing 5% sucrose supplemented with 0.001 mg 1 -a B.A. E polyandra produced higher percentages of globular ,somatic embryo development, while A. bilocu- laris consistently showed a lower percentage of globular somatic embryo development in all 5 concentrations of BA. MT basal medium containing 5% sucrose and sup- plemented with 0.001 mg 1-1 BA was found to be a suit- able medium for development of globular somatic em- bryos derived from protoplasts to form heart-shaped somatic embryos with cotyledon-like structures. The highest percentages of shoot fl)rmation for all 6 species were obtained using 0.1 mg 1 -] GA. 3. A complete proto- plast-to-plant system was developed for E polyandra, A. bilocularis and Z trifolia, which could facilitate the trans- fer of nuclear and cytoplasmic genes from these species into cultivated Citrus through protoplast fusion