Screening method for resistance to fusarium wilt of banana basing on green fluorescent protein tagged pathogen and root exudates.

A green fluorescent protein (sGFP) tagged Foc4 strain was developed by the method of PEG-CaCl2.The fluorescent signal was clearly visible in cytoplasm and nucleus of the hyphae and spores under the fluorescence microscopy.The transformed Foc retained its pathogenicity and growth patterns.Water culture of 9 banana cultivars with different resistance were performed for 15 days using 200 mL of sterile distilled water for each plantlet,and the root exudates were collected and bioassay for their effects on the GFP tagged Foc4.The results showed that the apolar fraction of the root exudates from the highly resistant cultivars could kill the pathogen.Those of the general resistant cultivars could inhibit the spore germination and hyphal growth,while the sensitive cultivars couldn’t.