16 research outputs found
Response of sugarcane (Saccharum sp.) varieties to embryogenic callus induction and in vitro salt stress
Response of three varieties of sugarcane (Saccharum sp.) to callus induction, embryogenic callus production and in vitro salt tolerance was studied. For callus induction and embryogenic callus production, leaf bases segments were subjected to in vitro culture on Murashige and Skoog (MS) medium supplemented with 3 mg 1-1 2,4 Dichlorophenoxyacetic acid for 4 weeks. To evaluate salt tolerance of the varieties, growing calli were exposed after two subsequent subcultures (4 weeks each) to different concentrations of NaCl (0, 17, 34, 68 and 102 mM) added to the culture medium for 4 weeks. Comparision of genotypes was based on callus induction percentage, embryogenic callus production percentage and relative fresh weight growth (RFWG). For salt tolerance, necrosis percentage and relative fresh weight growth of callus were used. The three varieties responded well to callus induction with a percentage of induction about 82, 84 and 100% for CP70-321, NCo310 and CP65-357, respectively. The high percentages of embryogenic callus obtained for the three varieties indicated that these varieties have a high capacity for embryogenic callus production. Relative fresh weight growth of callus was about 1.076, 1.282 and 0.925 for CP70-321, NCo310 and CP65-357, respectively. NaCl effect resulted in calli necrosis and a reduction of their growth. However, growing calli derived from varieties CP70-321 and NCo310 showed less necrosis percentages and less relative fresh weight growth reduction under salt stress. They appeared to be more salt tolerant in vitro than CP65-357.African Journal of Biotechnology Vol. 4 (4), pp. 350-354, 200
Auxin pretreatment promotes regeneration of sugarcane (Saccharum spp. hybrids) midrib segment explants
We have developed a new, simple,
quick and genotype-independent method for direct
regeneration of sugarcane using novel midrib
segment explants. Our protocol involves two
steps: the pretreatment of starting material on MS
(Murashige and Skoog (1962) Physiol Plant
15:473–497) medium containing 3.0 mg/l 2,4-
dichlorophenoxyacetic acid (2,4-D) for 8 days
under continuous dark and subsequent transfer of
the explants to MS medium augmented with
0.1 mg/l benzyladenine (BA) and 0.1 mg/l naphthaleneacetic
acid (NAA) under light-dark conditions.
On the regeneration medium, numerous
globular structures appeared from the explants
and subsequently differentiated into shoots.
Regenerated shoots attained 2–5 cm height
within 30 days of culture initiation and readily
rooted on MS basal medium. Hardened plants
were successfully established in the greenhouse.
The regulation of sugarcane morphogenesis by
auxin pretreatment is discussed
Initiation of embryogenic cell suspensions of taro (Colocasia esculenta var. esculenta) and plant regeneration
Embryogenic callus was initiated by culturing in vitro taro corm slices on agar-solidified half-strength MS medium containing 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) for 20 days followed by transfer to 1.0 mg/L thidiazuron (TDZ). Callus was subsequently proliferated on solid medium containing 1.0 mg/L TDZ, 0.5 mg/L 2,4- D and 800 mg/L glutamine before transfer to liquid medium containing the same components but with reduced glutamine (100 mg/L). After 3 months in liquid culture on an orbital shaker, cytoplasmically dense cell aggregates began to form. Somatic embryogenesis was induced by plating suspension cells onto solid media containing reduced levels of hormones (0.1 mg/L TDZ, 0.05 mg/L 2,4-D), high concentrations of sucrose (40–50 g/L) and biotin (1.0 mg/L). Embryo maturation and germination was then induced on media containing 0.05 mg/L benzyladenine (BA) and 0.1 mg/L indole-3-acetic acid (IAA). Histological studies of the developing embryos revealed the presence of typical shoot and root poles suggesting that these structures were true somatic embryos. The rate of somatic embryos formation was 500–3,000 per mL settledcell volume while approximately 60% of the embryos regenerated into plants