Increased production of azadirachtin from an improved method of androgenic cultures of a medicinal tree Azadirachta indica A. Juss.

Abstract

This report is the first direct evidence of azadirachtin production in androgenic haploid cultures of Azadirachta indica, a woody medicinal tree. Anther cultures at early-late-uninucleate stage of microspores were established on MS medium with BAP (5 µM), 2,4-D (1 µM) and NAA (1 µM) containing 12% sucrose. The calli, induced, were further multiplied on 2,4-D and Kinetin media. Shoots, differentiated on BAP (2.2 µM) + NAA (0.05 µM) medium, were elongated on MS + BAP (0.5 µM) and multiplied on MS + BAP (1 µM) + CH (250 mg/l). Thereafter, the shoots were rooted on 1/4 MS + IBA (0.5 µM). Cytological analysis of the calli and regenerants have confirmed their haploid status with the chromosome number as 2n=x=12. The haploid cell lines and leaves from in vitro grown plantlets were analyzed for azadirachtin by RP-HPLC and mass spectroscopy. Maximum azadirachtin (728.41 µg/g DW) was detected in calli supporting best shoot proliferation while least (49 µg/g DW) was observed in an undifferentiated line from maintenance medium. This study has brought us a step closer to develop genetically pure lines that could serve as new and attractive alternative ways of homogeneous controlled production of high value compounds, round the year, independent of geographical and climatic barrier.