Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University1
School of Forestry and Biotechnology, Zhejiang Agricultural & Forestry University2
Agricultural Bureau of Zigui County, Yichang3
The synthesis of chimeras is a breeding approach for horticultural crops. In our breeding program, a new diploid citrus chimera, named ‘Hongrou Taoye’ (Citrus sinensis [L.] Osbeck + Citrus unshiu Marc.), was found arising at the junction where a ‘Taoye’ sweet orange (C. sinensis) scion was grafted onto Satsuma mandarin (C. unshiu). As an artificial chimera, its fruit traits derived from the L1 cell layer, with juice color and carotenoid complement, in which β-cryptoxanthin accumulated predominantly, similar to those of Satsuma mandarin. By contrast, traits originating from the L2/L3 cell layer, including pollen, seed, and rind aroma characteristics, were the same as those of ‘Taoye’ sweet orange (the scion). SSR and cpSSR analyses showed that both nuclear and chloroplast genomes of the chimera were a combination of both donor parents. ‘Hongrou Taoye’ thus combined the valuable traits of both donor plants, and therefore has good potential in citrus fresh market.
1. Bae, C.H., T. Abe, N. Nagata, N. Fukunishi, T. Matsuyama, T. Nakano, and S. Yoshida. 2000. Characterization of a periclinal chimera variegated tobacco (Nicotiana tabacum L.). Plant Sci. 151:93-101.
2. Burge, G.K., E.R. Morgan, and J.F. Seelye. 2002. Opportunities for synthetic plant chimeral breeding: past and future. Plant Cell, Tissue Organ Cult. 70:13-21.
3. Chen, L.P., Y.M. Ge, and X.Y. Zhu. 2006. Artificial synthesis of interspecific chimeras between tuber mustard (Brassica juncea) and cabbage (Brassica oleracea) and cytological analysis. Plant Cell Rep. 25:907-913.
4. Cheng, Y.J., M. Carmen, H.J. Meng, W.W. Guo, N.G. Tao, and X.X. Deng. 2005. A set of primers for analyzing chloroplast DNA diversity in Citrus and related genera. Tree Physiol. 25:661-672.
5. Cheng, Y.J., W.W. Guo, and X.X. Deng. 2003b. cpSSR: a new tool to analyze chloroplast genome of Citrus somatic hybrids. Acta Bot. Sin. 45:906-909.
6. Cheng, Y.J., W.W. Guo, H.L. Yi, X.M. Pang, and X.X. Deng. 2003a. An efficient protocol for genomic DNA extraction from citrus species. Plant Mol. Biol. Rep. 21:177a-177g.
7. Clayberg, C.D. 1975. Insect-resistance in a graft-induced periclinal chimera of tomato. HortScience 10:13-15.
8. Deng, X.X. 2005. Advances in worldwide citrus breeding. Acta Hortic. Sin. 32:1140-1146.
9. Frost, H.B., and C.A. Krug. 1942. Diploid-tetraploid periclinal chimeras as bud variants in citrus. Genetics 27:619-634.
10. Goffieda, J.C., E.J. Szymkowiak, I.M. Sussex, and M.A. Mutschler. 1990. Chimeric tomato plants show that aphid resistance and triacylglucose production are epidermal autonomous characters. Plant Cell 2:643-649.
11. Jorgensen, C. A. 1927. A periclinal tomato-potato chimera. Hereditas 10:293-301
12. Kijas, J.M., J.C. Fowler, C.A. Garbett, and M.R. Thomas. 1994. Enrichment of microsatellites from the citrus genome using biotinylated oligonucleotide sequences bound to streptavidin- coated magnetic particles. Biotechniques 16:657-662
13. Kuhara, S. 1989. Artificial production of citrus periclinal chimera and disease resistance of these plants. Plant Protection (Shokubutsu Bochi) 43:25-29.
14. Lee, H.S., W.S. Castle, and G.A. Coates. 2001. High-performance liquid chromatography for the characterization of carotenoids in the new sweet orange (Early gold) grown in Florida, USA. J. Chromatogr., A 913:371-377.
15. Marcotrigiano, M., and R. Bernatzky. 1995. Arrangement of cell layers in the shoot apical meristems of periclinal chimeras influences cell fate. Plant J. 7:193-202.
16. Ohtsu, Y., and S. Kuhara. 1994. Periclinal chimera of citrus resistant to citrus canker and citrus tristeza virus: Chimerism and composition of fruit tissue in the synthetic periclinal chimeras ‘FN-1’ and ‘FN-3’. Annu. Phytopathol. Soc. Jpn. 60:20-26.
17. Shen, D.X., Y.Y. Wang, and L.G. Chen. 1998. Citrus genetics and breeding. Scientific Publishers, Beijing, China (in Chinese).
18. Sugawara, K., T. Wakizuka, A. Oowada, T. Moriguchi, and M. Omura. 2002. Histogenic identification by RAPD analysis of leaves and fruit of newly synthesized chimeric Citrus. J. Am. Soc. Hortic. Sci. 127:104-107.
19. Szymkowiak, E., and E. Irish. 1999. Interactions between jointless and wild-type tomato tissues during development of the pedicel abscission zone and the inflorescence meristem. Plant Cell 11:159-176.
20. Szymkowiak, E., and I. Sussex. 1992. The internal meristem layer (L3) determines floral meristem size and carpel number in tomato periclinal chimeras. Plant Cell 4:1089-1100.
21. Tanaka, Y. 1980. An iconograph of Japanese citrus fruits: A monographic study of species and varieties of citrus fruits grown in Japan. Yokendo Co., Tokyo, Japan.
22. Tilney-Bassett, R.A.E. 1986. Plant chimeras. Edward Arnold Publishers, London, UK.
23. Wang, Y., Q. Cheng, X.Y. Zhu, L.P. Chen. 2011. Studies on reproductive characteristics of an interspecific chimera between Brassica juncea and Brassica oleracea. Plant Cell, Tissue Organ Cult. 104:209-215.
24. Winkler, H. 1907. Description of S. nigrolycopersicum and method of obtaining graft-hybrids. Ber eut Bot. Ges. 25:568-576.
25. Wu, H.M., B.M. Lin, Z.X. Lai, L.X. Lu, G.F. Lin, D.M. Pan, and J.F. Yang. 2004. An intergeneric grafting chimera name: +Citroponcirus ‘Hormish’. J. Trop. Subtrop. Bot. 12:177-181 (in Chinese).
26. Zhang, M., X.X. Deng, C.P. Qin, C.L. Chen, H.Y. Zhang, Q. Liu, Z.Y. Hu, L.L. Guo, W.H. Song, Y. Tan, and S.C. Liao. 2007. Characterization of a new natural periclinal navel-satsuma chimera of citrus: ‘Zaohong’ navel orange. J. Am. Soc. Hortic. Sci. 132:374-380.
27. Zhou, J.M., Y. Hirata, I.S. Nou, H. Shiotani, and T. Ito. 2002. Interactions between different genotypic tissues in citrus graft chimeras. Euphytica 126:355-364.
28. Zhu, X.Y., M. Zhao, S. Ma, Y.M. Ge, M.F. Zhang, and L.P. Chen. 2007. Induction and origin of adventitious shoots from chimeras of Brassica juncea and Brassica oleracea. Plant Cell Rep. 26:1727-1732.