Molecular and Genetic Characterization of Nicotiana glutinosa L. Chromosome Segments in Tobacco mosaic virus‐Resistant Tobacco Accessions

Abstract

on the derivation and existence of this material is fragmentary (Ternovsky, 1941(Ternovsky, , 1945Goodspeed, 1942; Kos-Tobacco mosaic virus (TMV)-resistant flue-cured tobacco (Nicotitoff and Georgieva, 1944; Kostoff, 1948; Valleau, 1952; ana tabacum L.) cultivars have been developed using the N gene Oka, 1961). derived from N. glutinosa L. Their adoption has been low, however, because of unfavorable linkage drag effects. Strategies to overcome It was later demonstrated that recombination could this problem might include pursuit of alternative introgression events occur between chromosome H and the N-carrying chroand/or use of molecular markers for selection against deleterious alien mosome in Holmes Samsoun (Gerstel and Burk, 1960), chromatin. Previous workers demonstrated the presence of a TMVand this line is believed to have been the ultimate source resistance mechanism on more than one chromosome of the tobacco of TMV resistance used in all tobacco breeding in the genome. The objectives of this research were to determine the relative USA (Valleau, 1952; Wernsman, 1992). High yielding genomic positions of TMV resistance loci in a set of 12 TMV-resistant cultivars of burley tobacco with N-mediated resistance tobacco accessions and to use amplified fragment length polymorhave been developed and accepted by growers. TMVphism (AFLP) markers for characterization of this material with reresistant flue-cured cultivars have also been developed. spect to linked alien chromatin. Five accessions were found to carry These have not been widely grown, however, because a TMV resistance gene on chromosome H. Seven accessions were found to carry a resistance factor on an alternative chromosome. of decreased yield and quality associated with the resis-Polymerase chain reaction results indicated that the N gene from N.tance. Available data suggest that these negative associglutinosa is responsible for resistance in all 12 accessions. A set of ations are due to linkage drag effects rather than pleiot-168 AFLP markers specific to the N. glutinosa donor chromosome

Use of transferableNicotiana tabacumL. microsatellite markers for investigating genetic diversity in the genusNicotiana

“…DNA markers have also been useful for facilitating introgression of wild germplasm into elite germplasm pools (Eshed and Zamir 1995;Tanksley and Nelson 1996;Huang et al 2003;Gur and Zamir 2004). The majority of published research involving molecular markers in tobacco has focused on identification of randomly amplified polymorphic DNA (RAPD) or amplified fragment length polymorphism (AFLP) markers linked to disease resistance genes introgressed from wild relatives (Bai et al 1995;Yi et al 1998;Johnson et al 2002;Lewis 2005;Milla et al 2005b;Lewis et al 2005;Moon and Nicholson 2007). Mapping of genes of N. tabacum origin has been limited, however, because of the relatively low rates of polymorphism detected using these marker systems (Ren and Timko 2001;Rossi et al 2001;Nishi et al 2003).…”

Scientific opinion addressing the safety assessment of plants developed through cisgenesis and intragenesis

“…There are examples of the use of translocations in tobacco (transfer of tobacco mosaic virus resistance from Nicotiana glutinosa to N. tabacum) and wheat (rust resistances from rye and wild diploids) (Ko et al, 2002;Lewis et al, 2005).…”

“…If a translocated fragment contains the desired gene but no other genes with undesirable effects, and no undesirable position effects result from genes in new chromosome locations, the new recombinant chromosome can be incorporated in the genome of the cultivated species. There are examples of the use of translocations in tobacco (transfer of tobacco mosaic virus resistance from Nicotiana glutinosa to N. tabacum) and wheat (rust resistances from rye and wild diploids) (Ko et al, 2002;Lewis et al, 2005).…”

Development of DArT markers for a linkage map of flue-cured tobacco

“…From the first molecular marker restriction fragment length polymorphism (RFLP) reported by Botstein et al [5] in the 20th century, diverse molecular markers, such as randomly amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism markers (AFLPs), have been developed and used in crops. As in other crops, RFLP, RAPD and AFLP markers have been developed and used in tobacco since the 1990's [6][7][8][9][10][11][12][13]. Recently, simple sequence repeat (SSR) [1][2][3]14,15] and other new types of markers, such as small RNA-based molecular markers [16], have been further developed and used in studies of diversity and linkage mapping in tobacco.…”