ISSN:
1432-2242
Keywords:
Tobacco mosaic virus
;
Nicotiana tabacum
;
Kanamycin resistance
;
Hypersensitive response
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The hypersensitive response of tobacco to inoculation with tobacco mosaic virus (TMV) is controlled by a single dominant gene, the N gene. As a first step in localizing and transferring the N gene, we have prepared a line of tobacco plants in which the kanamycin-resistance (Kmr) gene is closely linked to the N gene. Nicotiana tabacum plants heterozygous for the N gene were transformed to Kmr by Agrobacterium carrying pMON200. Eighty-nine independent transformed clones were regenerated and were backcrossed with nontransformed, TMV-sensitive plants. Progeny from these crosses were screened first for Kmr; then the Kmr progeny were inoculated with TMV and scored for the hypersensitive response. Of the initial 89 clones, 68 appeared to have integrated a single functional Kmr gene. Initial tests for TMV resistance indicated possible linkage between Kmr and the N gene in 11 plants. With further testing, linkage has been established for two of these plant lines. In one of these lines, the two genes were 30–40 map units apart, and evidence of somatic instability in the linkage was obtained. However, in the second line, linkage between Kmr and the N gene was tight, and recombination between the genes in this case was only 5%. Southern hybridization revealed that this plant contained only a single copy of the Kmr gene. Linkage between Kmr and the N gene in this plant line has been verified in each of two additional backcross generations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00232960
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