Revista de fisiología y patología vegetal

Response of Different Salts as Alternative Nitrogen Source for Ginger (Zingiber officinal rosc.) In Vitro Regeneration

Genene Gezahegn1*, Tileye Feyissa2 and Yayis Rezene1

In Ethiopia, ginger is mainly produced in southern parts of the country specifically in some districts of Wolayta and Kambata Tambaro administrative zones. Its production is being challenged primarily due to bacterial wilt disease eruption as of 2012 production season. Use of disease free tissue culture generated seed rhizome as part of integrated management was considered as best option to reduce the disease impact. On the other hand, major media components like ammonium nitrate are not available for large scale in vitro propagation. To enhance disease free ginger in vitro propagation; experiment was designed with the aim to select alternative sources of nitrogen to replace unavailable ammonium nitrate due to its explosive nature and safety issue. Three nitrogen salts at different level were evaluated as part of MS medium for in vitro regeneration of Volvo ginger cultivar. Three alternative salts tasted (NH4Cl KNO3 and urea) were observed as potential replacements of NH4NO3 in MS medium supplemented with 2.0 mg/l BAP and 1.0 mg/l Kinetin. The highest mean shoot number (9.33) of shoots from media containing 1.0 g/l NH4Cl followed by mediums containing 1.9 g/l KNO3 and 4.5 g/l urea with record of mean shoot numbers 7.33 and 7.00 respectively. Whereas, the lowest explants survival and proliferation was observed on medium containing 2.0 g/l and 1.65 g/l NH4Cl. Root formation and survival after acclimatization were also affected negatively at elevated levels of NH4Cl. The highest mean number of roots was observed on medium supplemented with 1.0 g/l NH4Cl followed by normal MS media. In contrary, the lowest root number (4) was observed on medium containing 2.0 g/l NH4Cl. Survival after acclimatization was found to be 98% for plants derived from medium containing 4.5 and 1.9 g/l urea and KNO3 respectively followed by 95% for plants derived from medium containing 1.0 g/l NH4Cl. This experiment revealed that the three nitrogen salts can be used as nitrogen source. But urea (3 g/l to 4.5 g/l) was the first option for ginger in vitro propagation which ensures availability and low cost tissue culture technique.