The Research of Biological Characteristics and Chlorophyll Fluorescence Parameters Diurnal Fluctuations of Autotetraploid 'Hanfu'Apple Leaves

摘要

Most of the polyploidy grow vigorously with higher yield, stronger adaptability and better disease resistance. With the well developed in vitro regeneration technique, autopolyploid induced in vitro has become an effective way of polyploidy breeding in apple. There is no report about autopolyploidy apple. Here the paper studied the biological characteristics and chlorophyll fluorescence parameters diurnal fluctuations of autotetraploid 'Hanfu' apple leaves. The autotetraploid apple was doubled by colchicin from a diploid. The autotetraploid apple appeared dwarf and the color of its leaves were greener than diploid. The characteristics analysis of leaf structure supported the phenomenon of autotetraploid the dwarf. Stomatal density analysis suggested that the disease resistance of autotetraploid apple was better than the diploid. The contents of chlorophyll a, chlorophyll b and carotenoid in autotetraploid apple are significantly higher than the diploid. The fluorescence performance index PI value of autotetraploid, based on absorbing light energy, was also higher than the diploid. Both chlorophyll content and fluorescence parameters indicated that autotetraploid apple had better photosynthetic performance than the diploid. This study provided a good example of polyploidy breeding.