Effect of genotype on callus induction and plant regeneration from leaf explants of sugarcane (Saccharum sp.)

Nine sugarcane genotypes (CP59-73, CP63-588, CP80-314, SP71-1081, F160, L62-96, CP70-321, CP57- 614 and Clone III) were evaluated for their callus induction capacity, embryogenic callus production and plant regeneration ability. Leaf cylinders were used as explants using Murashige and Skoog (MS) based medium supplemented with 3 mg l-1 2,-4 dichlorophenoxyacetic acid. Plant regeneration was accomplished on hormone free modified MS medium supplemented with casein hydrolyzate. The genotypes tested showed high callus induction percentage (69 to 95%) and high embryogenic callus percentage (60 to 100%). These genotypes also showed excellent regeneration capacities, with regeneration percentages ranged between 88 and 100%. Significant differences were observed between genotypes for callus induction capacity, embryogenic response and plant regeneration ability indicating that these criteria are genotype dependent. Plant regeneration ability is highly correlated with embryogenic callus production. The in vitro regenerated plants were successfully rooted and well acclimatised in growth cabinet conditions

Growth, proline and ion accumulation in sugarcane callus cultures under drought-induced osmotic stress and its subsequent relief

Calli obtained from two sugarcane cultivars (R570 and CP59-73) were exposed to different osmotic stress intensities followed by a period of stress relief. Relative rate growth, callus water content and changes in organic and inorganic solutes were determined at the end of stress and relief periods. After the stress period, calli derived from both cultivars showed a decrease in RGR, but at lesser extent in R570 than CP59-73 cultivar. Same tendency was recorded in the callus water content under mannitolinduced osmotic stress. The inorganic solutes seemed to have no contribution in the osmotic adjustment in mannitol-stressed calli since K+ and Ca2+ concentrations decreased drastically while Na+ and Mg2+ concentrations were not affected. The accumulation of proline occurred in both cultivars and was more marked in CP59-73 than R570 cultivar. At the end of the relief period, we observed that all the considered parameters have recovered completely to reach the control levels. According to these results, we conclude that the drought stress-induced changes are reversible, at the least at the cellular level, in sugarcane cultivar

In vitro culture techniques as a tool of sugarcane bud germination study under salt stress

Germination was the first stage confronted to soil salinity and it is important to determine salt effects on this stage. In this study, we reported an in vitro procedure for studying sugarcane bud germinationand shoot growth under salt stress with different NaCl concentrations (0, 17, 34, 68 and 102 mM) using cultivar NCo310. Germination percentage of control was about 92% after 8 days. Germination of buds,plant fresh and dry mass decreased with increasing salinity. Data indicated that in vitro culture techniques could be used to evaluate salt stress effects in sugarcane at the germination stage

Phasenverhalten von Polyethylen in Mischsystemen

The phase behavior of PE in mixed systems is studied in this thesis. Theoretical aspects: thermodynamics of polymer solutions, IPNs, polymerization-induced phase separation. PE in non-reactive systems: solvents, alkanes, mixed solvents. PE in reactive systems: polymerization with BPO, polymerization with DCPO, glass transition temperature, crystallinity.SIGLEAvailable from: <a href=http://ArchiMeD.uni-mainz.de/pub/2003/0051/diss.pdf target=NewWindow>http://ArchiMeD.uni-mainz.de/pub/2003/0051/diss.pdf</a> / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman