Effect of different concentrations of NaCl on micropropagation of Mentha sp.

Wild type species of Mentha was assayed in vitro for salinity (NaCl) tolerance. Micro propagated subcultured stem of Mentha was used to assay shoot length, multi shooting, root length, root number, and the emergence of leaves. Different concentration of NaCl (0.1 mg/ml, 0.2 mg/ml, 0.3 mg/ml and 0.4 mg/ml) supplemented in MS media was used for different treatments. Data was recorded after various periods (7 days, 14 days, 21 days, and 28 days) of time. The study reveal that shoot length increases favourably at low concentration of NaCl (0.1 mg/ml and 0.2 mg/ml) but at higher concentration (0.3mg/ml and 0.4 mg/ml) there is a reduction in length. Number of emerged shoots increases during every treatment.  The number, however, gets inhibited at 0.4mg/ml of NaCl. NaCl's concentration (except 0.4 mg/ml, which completely inhibits emergence) seems to favor the emergence of roots. The number seems to be the greatest at 0.3 mg/ml of NaCl. Every concentration of NaCl except for 0.4 mg/ml (which completely inhibits the growth) inhibits the root length.  Every concentration of NaCl has been found to favour the emergence of leaf in the propagated plantlet. A concentration of 0.3 mg/ml has been found to initiate the emergence of leaves the fastest. The emergence of leaves could also be noticed at 0.3 mg/ml and 0.4 mg/ml even after 21 days of incubation. The finding mentioned above can be useful in future research on micropropagation. The details of each finding is described.