Dear Pathak,

Here is a shoot's disinfecting method used by Shekhawat et al., 2015 :

The explants were pretreated with 0.1% (w/v) Bavistin (a systemic fungicide; BASF India Ltd., India) solution, and subsequently the surface was sterilized with 0.1% (w/v) HgCl2 (disinfectant, Himedia, India) solution for 5 min to check fungal and bacterial contamination, respectively. After rinsing five to six times with sterile distilled water, the explants were dipped in 90% ethyl alcohol. The sterilized explants were inoculated vertically onto the culture medium under laminar air flow cabinet (Technico Pvt. Ltd., Chennai, India).

Thank you Ramez Saad,

I have also used both bavistin and HgCl2 at the time of inoculation and it appeared after 2-3 weeks. Sometimes this appeared even after sub-culturing i.e. 5-6 weeks after inoculation. So I thought it would be bacterial contamination but I have confirmed that it wasn't because of contamination.

Dear Pathak

This problem does not appear to be due to explant exudates and may be due to internal contamination. How do you test the absence of bacterial infection?

Hello

I agree with Dr. Miri. Whould you please take a picture of samples. I guess it could be helpful.

Best wishes