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| Author(s): |
Alexandra Pavan
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2006-08-28 |
| Examining board members: |
Francisco de Assis Alves Mourão Filho;
Maria Angélica Pereira de Carvalho Costa;
Beatriz Madalena Januzzi Mendes
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| Advisor: | Francisco de Assis Alves Mourão Filho |
| Abstract | |
This research aimed to produce new somatic hybrid combinations between sweet orange (Citrus sinensis) with mandarins (C. reticulata, C. reshni, C. Sunki, C. deliciosa), tangors (C reticulata x C. sinensis) or Orlando tangelo (C. reticulata x C. paradisi), and also evaluate the somatic hybrid Hamlin sweet orange (Citrus sinensis) + Montenegrina mandarin (Citrus deliciosa) for resistance to Xanthomonas axonopodis pv. citri and Xylella fastidiosa. Protoplast sources included embryogenic calli or suspension-culture derived calli, and leaves collected from plants cultivated in vitro or in screenhouses. After protoplast isolation, embryogenic protoplasts were chemically fused by polyethylene glycol (PEG) with mesophyll-derived non-embriogenic protoplasts. Fusion-derived calli were further cultured to embryo induction, germination, and plant regeneration. Regenerated plants were individually rooted or micrografted, and further acclimated in screenhouse. Somatic hybridization was confirmed by analysis of leaf morphology, molecular analysis by RAPD markers, ploidy determination by chromosome counting or flow cytometry. The producion of the somatic hybrids Hamlin sweet orange + Montenegrina mandarin and Hamlin sweet orange + Dancy mandarin was confirmed. These hybrids may have complementary traits from both progenitor and be used directly as scion cultivars or as parental lines in scion improvement programs. Hamlin sweet orange + Montenegrina mandarin somatic hybrid was resistant to Xanthomonas axonopodis pv. citri and Xylella fastidiosa. (AU) | |