Somatic Embryogenesis in Anise (Pimpinella Anisum L.): The Effect of Proline on Embryogenic Callus Formation and Aba on Advanced Embryo Development

The effects of cytokinins, carbohydrates and amino acids were studied on maturation and regeneration of embryogenic callus (EC) in kodo millet (Paspalum scorbiculatum Linn.) using a two-step culture procedure. The highest percentage (87.6%) of EC induction was obtained in the induction medium containing Murashige and Skoog (MS) basal salts supplemented with 9.0 lM 2,4-dichlorophenoxy acetic acid and 2.25 lM kinetin. This EC was subcultured in the maturation medium for somatic embryo (SE) maturation and plantlet formation. Addition of cytokinins, carbohydrates and amino acids in the maturation medium promoted the SE maturation and plantlet formation. The maturation medium containing MS basal salts amended with 4.50 lM thidiazuron, 120 mM maltose and 200 lM L-proline gave the maximum number of SEs (39.4) and plantlets (31.3). Plantlets were successfully grown to maturity after hardening in the soil.

Section: Discussionmentioning

confidence: 96%

Effects of cytokinins, carbohydrates and amino acids on induction and maturation of somatic embryos in kodo millet (Paspalum scorbiculatum Linn.)

Ceasar¹,

Ignacimuthu²

2010

“…Enrichment of the regeneration medium with amino acids and increased sucrose level may account for the differential response. The addition of amino acids to the culture medium has been shown to be beneficial to morphogenetic expression (Moghaddam et al 2000;Bela and Shetty 1999). With stem-derived callus of Tribulus terrestris, the addition of casein hydrolysate and yeast extract improved somatic embryogenesis of Tribulus terrestris callus cultures (Mohan et al 2000).…”

Section: Morphogenetic Responsementioning

confidence: 97%

Plant regeneration using immature zygotic embryos of Tribulus terrestris

Palmer

Keller

2010

The genus Tribulus is the source of a number of steroidal saponins and other bioactive compounds which are of medicinal and pharmaceutical importance and plant regeneration of Tribulus terrestris has been reported. The objective of this study was to evaluate the potential of immature zygotic embryos of Tribulus terrestris as an explant for plant regeneration. Embryos were cultured on MS medium supplemented with 1-naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D) and thidiazuron (TDZ), alone or in combination and callus and shoot or embryo formation evaluated. With 2.5 mg/l NAA or 2,4-D, callus formation frequency was 100% but 57% with 2.5 mg/l TDZ. The combination of 2.5 mg/l TDZ and NAA or 2,4-D also elicited callus formation frequency of 100%. The callus formation frequency was lower with lower levels of these growth regulators. On a medium with 0.5 mg/l TDZ, 17.4% of the 2,4-D-derived callus (2.5 mg/ l), developed embryo-like structures and this increased to 37.3 and 41.4% respectively, when TDZ was combined with 0.5 mg/l indole-3-butyric acid (IBA) or 2,4-D. Both shoot formation and embryo-like structures developed in cultures with 2.5 mg/l TDZ, alone or in combination with 0.5 mg/l IBA or 2,4-D. The optimum sucrose level for morphogenetic response of embryo-derived callus was between 5.0 and 7.5%. Embryo-like structures were also observed when the 2,4-D-derived callus was cultured in a liquid containing benzyladenine (BA) and IBA. Plants were regenerated from both embryo-like structures and shoot buds on solid MS medium containing 0.2 mg/l IBA and rooted plantlets were transferred to soil.

“…While the addition of casein hydrolysate and L-proline did not affect the frequency of callus formation, they were nevertheless beneficial to embryo formation. Amino acids have been shown to exert beneficial effects on somatic embryo formation and development by providing a ready source of reduced nitrogen (Mohamed et al 2004;Bela and Shetty 1999). High levels of sucrose may exert an osmotic stress effect which is conducive to the somatic embryo induction process (Gaj 2004;Lou and Kako 1995).…”

Section: Discussionmentioning

confidence: 98%

Somatic embryogenesis in Crambe abyssinica Hochst. ex R.E. Fries using seedling explants

Palmer

Keller

2010

Somatic embryogenesis in Crambe abyssinica, an important industrial oilseed species, was investigated. Cotyledon, hypocotyl and root explants from 8-day-old seedlings of C. abyssinica cv. Prophet were cultured with levels of 1-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) ranging from 2.2 to 39.0 lM, combined with 6-benzyladenine (BA) to achieve an auxin:cytokinin ratio of 20:1, and callus formation assessed. Callus formation frequency for cotyledon and hypocotyl explants was 100% for levels of 2,4-D from 4.5 to 33.9 lM. The response was similar with NAA levels of 13.0 to 39.0 lM. Root explants were less responsive. When calluses were transferred to a medium containing 0.56 lM each of thidiazuron and BA with 1.0 lM indole-3-butyric acid (IBA), somatic embryos were induced. Moreover, embryos were induced from calluses grown on media containing either 11.3 lM 2,4-D or 13.0 lM NAA, or higher. On a medium without plant growth regulators, embryos were induced but at a much lower frequency. For all three explants, 22.6 lM 2,4-D and 26.0 lM NAA was optimal for embryogenic callus induction. Hypocotylderived calluses were superior to cotyledon-and rootderived calluses for embryo induction. The best embryo formation response was with medium containing 5.0-6.0% sucrose. The highest average number of embryos per callus (36) was obtained from hypocotyl calluses from medium with 22.6 lM 2,4-D. Somatic embryos germinated best on half-strength B5 or MS medium with 3% sucrose, and plantlets were successfully established under greenhouse conditions. The results indicate that high levels of auxins are required for the induction of embryogenic calluses from explants of C. abyssinicia, while cytokinins are critical for somatic embryo formation.