Fusarium wilt-resistant lines of Brazil banana (Musa spp., AAA) obtained by EMS-induced mutation a micro-cross-section cultural system

Abstract

This study combined the micro-cross-section cultural system with vitro mutagenesis induced by ethyl methanesulphonate (EMS) to screen for fusarium wilt-resistant lines of Brazil banana (Musa spp., AAA). The results indicated that the optimum EMS concentration and duration for the treatment of micro-cross-sections cut from the pseudostem of tissue-cultured plantlet were 300mm and 60min, respectively. Under the optimal treatment, an average of 2·2 regenerated shoots were produced from each explant. One hundred regenerated plantlets were used for screening for fusarium wilt-resistant lines by the early screening technique. The initial disease symptom - yellowing lower leaves of susceptible plantlets - was observed 2weeks after inoculation. After 2months, only six plants survived - the putative fusarium wilt-resistant lines. The fusarium wilt pathogen Fusarium oxysporum f. sp. cubense race 4, was identified the preliminary test field by a SCAR marker technique. Of the six putative resistant lines, five survived the preliminary field test. The regenerated plantlets from these five fusarium wilt-resistant lines were subjected to early screening again, where they showed markedly reduced disease incidences compared with regenerated plantlets of Brazil banana (control). It was concluded that EMS-induced mutation of banana through the micro-cross-section cultural system is potentially useful for banana improvement. © 2012 BSPP.