Publication:

In vitro selection for Fusarium oxysporum f. sp. conglutinans resistance in brassica vegetables

Background Fusarium wilt is an issue of concern in economically and nutritionally important Brassica vegetable cultivation. Thus, it deserves measures against the adverse production impact caused by Fusarium wilt.

Methods In this study, development of resistance to F. oxysporum f. sp. conglutinans in six white head cabbage cultivars, by in vitro chemical mutagenesis and selection, through direct and indirect organogenesis was examined. 6 day and 10 day old hypocotyl, shoot tip and calli, from 6 day old hypocotyl explants, were subjected to chemical mutagenesis treatment (DMSO (4% v/v) + EMS (0.3% v/v) for two hours at 28±2°C) were incubated in MS shoot induction medium (MS+ NAA (0.2 mg/l), BAP (3 mg/l), GA3 (0.01 mg/L) and AgNO3 (0.5 mg/l)). Shoots developed from hypocotyl and shoot tip explants (in the MS shoot induction medium and then in MS + NAA (0.2 mg/l), BAP (3 mg/l), GA3 (0.01 mg/l) for shoot development) and calli following mutagenesis treatment were screened for Fusarium resistance subjecting to 15% and 20% Fusarium culture filtrate for 30 and 60 day selection periods for each strength respectively.

Results Developed plantlets from all six cultivars tested, showed resistance to Fusarium culture filtrate in the in vitro conditions with different survival frequencies ranging between 12.5% to 84.0% from hypocotyl and 0.0% to 86.7% from shoot tip explants among cultivars indicating development of resistance to Fusarium by in vitro chemical mutagenesis.

Conclusions Direct organogenesis, and 10 day old hypocotyl and 6 day old shoot tips are potential explants for successful application of in vitro chemical mutagenesis for Fusarrium resistance development in in cabbage.