ISHS Acta Horticulturae 773: XXVII International Horticultural Congress - IHC2006: International Symposium on Citrus and Other Tropical and Subtropical Fruit Crops
CITRUS GENETIC TRANSFORMATION WITH INTEREST TARGET GENES AND FURTHER USES OF TRANSGENIC LINES IN SOMATIC FUSION |
| Authors: | W.W. Guo, Y.X. Duan, D.L. Li, X. Liu, B. Tan, X.D. Cai, J.W. Grosser, X.X. Deng |
| Keywords: | orange, Satsuma mandarin, mandarin, tangor, trifoliate orange, transgenic fusion, cultivar improvement |
| Abstract:
Citrus is one of the most important fruit crops in China and worldwide. Genetic transformation using more recently cloned target genes is an effective alternative method for citrus improvement. In our laboratory, transformation systems using several explant sources such as protoplasts, embryogenic calli and epicotyl segments have been well established and optimized. Protoplast and embryogenic callus, as explants, are convenient to use and available at any time for transformation of seedless cultivars. Epicotyl segments from seed germination as explants are only available for seedy cultivars. The organogenesis of epicotyl segments of ‘Bingtang’ sweet orange (Citrus sinensis), an elite citrus cultivar in China, was optimized recently. Different cutting modes (i.e. transversal, longitudinal, and oblique) were compared, and their effect on the number and quality of regenerated buds and shoots was observed. Oblique cut, which was first reported, showed the best result. With the optimized regeneration systems, genetic transformation using several target genes, such as green fluorescent protein (GFP, an in vivo visual marker), LFY, AP1 (to shorten juvenility), Xa21 (for potential citrus bacterial canker resistance), and Barnase (to induce seedless fruit), was conducted. Numerous transgenic plants were regenerated from several citrus cultivars. Southern blot analysis confirmed the integration of target genes in the plant genome. Transgenic lines containing the GFP gene are also being used in somatic fusion for several purposes. Further evaluation of these transgenic materials for cultivar improvement is needed. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
