Effect of plant-derived smoke extract on in vitro plantlet regeneration from rapeseed (Brassica napus L. cv. Topas) microspore-derived embryos

The effect of aqueous smoke extract, derived from Tanacetum parthenium, onin vitro plantlet regeneration from rapeseed (Brassica napus L. cv. Topas)microspore-derived embryos (MDEs) was evaluated in this study. Inoculation ofrapeseed MDEs with the smoke-extract dilutions (1:250, 1:500, 1:1000 and 1:2000)for various times (5, 10 and 15 min) significantly enhanced the percentage ofregenerated plantlets from these embryos and also decreased the callogenesispercentage in these explants. The root length and shoot length of inoculated MDEswere significantly improved with all smoke-extract dilutions except for dilutions of1:100 and 1:10. Application of smoke-extract solutions (1:1000, 1:500, 1:250 and1:100) in B5 regeneration medium significantly enhanced the plantlet regenerationfrom rapeseed MDEs compared to control cultures. Furthermore, use of smokeextractsolutions in combination with GA3 (0.1 and 0.15 mgl-1) significantlyimproved the root length and shoot length of rapeseed MDEs compared to separateuse of smoke-extract solutions. Use of filter paper saturated with aqueous smokeextract (1:250) on top of the B5 regeneration medium was the best smoke treatmentmethod improving the plantlet regeneration percentage, root length and shootlength of rapeseed MDEs compared to other treatment methods. The conversionfrequency of rapeseed MDEs pretreated with smoke extract dilution of 1:500 wasimproved up to 50% compared with the control MDEs (26.67%), whereas the useof smoke extract (1:100) in B5 regeneration medium enhanced the conversionfrequency of these MDEs up to 62% compared with the control cultures (