caa a22 4500 475796543 CHVBK 20180406123726.0 cr unu---uuuuu 170329e20000301xx s 000 0 eng 10.1007/s001220051356 doi (NATIONALLICENCE)springer-10.1007/s001220051356 Improved resistance to bacterial soft rot by protoplast fusion between Brassica rapa and B. oleracea [Elektronische Daten] [J. P. Ren, M. H. Dickson, E. D. Earle] Abstract : Erwinia soft rot is a destructive disease of Brassica rapa vegetables. Reliable sources of resistance and control methods are limited, so development of highly resistant breeding lines is desirable. Protoplasts from B. rapa and B. oleracea genotypes selected for resistance to soft rot were fused in order to combine different sources of resistance. Twelve somatic hybrids (synthetic B. napus) were obtained and confirmed by morphology, nuclear DNA content, and RAPD analysis. They were normal looking plants that easily set seeds following self-pollination and backcrossing to B. rapa. Assays of detached leaves or seedlings inoculated in a mist-chamber showed that most somatic hybrids had lower disease severity ratings than the B. rapa fusion partner and a commercial variety of B. napus. Some progeny from selfing or backcrossing of somatic hybrids to B. rapa showed much more resistance than either fusion partner. The offspring populations of the somatic hybrids (F1-S1 and F1-BC1) clearly moved to the resistant direction compared to the parents; the percentage of resistant plants increased from 21% (average of parents) to 36% (F1-S1) and 48% (F1-BC1). These results suggest that it may be possible to obtain highly resistant B. rapa lines by further backcrossing and selection. Springer-Verlag Berlin Heidelberg, 2000 Key words Bacterial soft rot nationallicence Disease resistance nationallicence Chinese cabbage nationallicence Protoplast fusion nationallicence Brassica rapa nationallicence B. oleracea nationallicence B. napus nationallicence Erwinia carotovora subsp. carotovora nationallicence Ren J. P. Department of Horticultural Sciences, New York State Agricultural Experimental Station, Geneva, NY 14456, USA, US aut Dickson M. H. Department of Horticultural Sciences, New York State Agricultural Experimental Station, Geneva, NY 14456, USA, US aut Earle E. D. Department of Plant Breeding, Cornell University, Ithaca, NY 14853-1901, USA Fax: +1-607-255-6683 e-mail: ede3@cornell.edu, US aut https://doi.org/10.1007/s001220051356 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001220051356 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ren J. P. Department of Horticultural Sciences, New York State Agricultural Experimental Station, Geneva, NY 14456, USA, US aut NATIONALLICENCE 700 1- Dickson M. H. Department of Horticultural Sciences, New York State Agricultural Experimental Station, Geneva, NY 14456, USA, US aut NATIONALLICENCE 700 1- Earle E. D. Department of Plant Breeding, Cornell University, Ithaca, NY 14853-1901, USA Fax: +1-607-255-6683 e-mail: ede3@cornell.edu, US aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer