Gene transfer as an important approach to resistance breeding in apple
Apple trees were genetically engineered to increase resistance to diseases such as fire blight, apple scab and powdery mildew. To increase resistance to fire blight, genes coding for antibacterial proteins have previously been used, such as attacin E from Hyalophora cecropia and lysozyme from bacteriophage T4. We used the gene coding for EPS-depolymerase from an Erwinia amylovora bacteriophage. The transgenic plants were analyzed with molecular and biochemical techniques. Their susceptibility to fire blight was evaluated in the greenhouse. To prevent the spread of transgenic seeds and pollen into the environment, we investigated introducing parthenocarpy and male sterility into transgenic apple plants. The plants obtained have been transferred to the greenhouse. Data on pollen development will be collected as soon as they form flower buds. The stability of transgene integration and expression were studied after long-term in vitro cultivation of transgenic lines. Some irregularities were detected after analysis of the data gathered by PCR, RT-PCR, ELISA and Southern Blot.