Abstract

The rice chitinase gene (CHI), the alfalfa defensin gene (alfAFP) and their bivalent gene (CHI-AFP) were introduced into tomato line Micro-Tom via Agrobacterium-mediated gene transfer method. Transformants were obtained and confirmed by GFP, PCR and Southern blot hybridization. One to four copies of transgene were integrated into the tomato nuclear genome. Transcription levels of chitinase, alfAFPand their bivalent gene CHI-AFP in various transgenic lines were determined using Northern blot and Western blot analysis. Performance test of resistance analyses to Botrytis cinerea with T₁ generation transgenic tomato lines showed the transgenic lines exhibited higher resistance to the pathogens infected than that of the non-transgenic plants and the resistance levels were related to expression levels of the transgene, showing dosage-effect. The transgenic tomato harboringCHI-AFP cassette showed the highest disease resistance; it suggested that co-transformation with alfAFP and chitinase gene was more effective than individual transformations on the resistance to B. cinerea. Some independent lines with high disease resistance, low variability and stable expression of transgenes could be selected for the further studies and molecular breeding.

Key words: Transgenic tomato, rice chitinase gene, alfalfa defensin gene, Botrytis cinerea.