caa a22 4500 475795385 CHVBK 20180406123722.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1007/s001220050061 doi (NATIONALLICENCE)springer-10.1007/s001220050061 Fine mapping of a quantitative trait locus (QTL) from Lycopersicon hirsutum chromosome 1 affecting fruit characteristics and agronomic traits: breaking linkage among QTLs affecting different traits and dissection of heterosis for yield [Elektronische Daten] [A. J. Monforte, S. D. Tanksley] Abstract : The near-isogenic Line TA523, containing a 40-cM introgression at the bottom of chromosome 1 from Lycopersicon hirsutum acc. LA1777, affects several agronomically important traits. A set of recombinant lines (subNILs) derived from the original NIL TA523 were developed in order to fine-map, by substitution mapping, the genetic factors included within the original introgression. In the current experiment, TA523 showed redder, rounded, less pigmented shoulder, lower-weighted fruits and higher brix, whereas higher yield and brix*yield was observed only in the hybrid TA253×TA209 suggesting heterosis for these traits. By substitution mapping we mapped independent genetic loci affecting brix, yield and fruit shape, whereas fruit weight, shoulder pigmentation and external color mapped to a position coincident with the brix locus. Analysis of the subNILs revealed that the gene action of most of the QTLs was additive or nearly additive. The exception was for the yield QTL which was dominant (d/a=0.7), eliminating the possibility that yield increase is due to true overdominance at a single gene locus. However, no negative yield effects were detected in other regions of the introgressed segment, as would be predicted by a dominance complementation model. Therefore, epistatic interactions among genetic factors along the introgressed segment are suggested as the cause of yield heterosis. Results from this study, combined with previous experiments involving different tomato wild species, demonstrate that the base of chromosome 1 of tomato contains multiple QTLs affecting various agronomic and fruit traits and that these effects can not be attributed to the pleiotropic effects of a single locus. Springer-Verlag Berlin Heidelberg, 2000 Key words Heterosis nationallicence Fine mapping nationallicence Genetic interactions nationallicence Yield nationallicence Brix nationallicence Monforte A. J. Department of Plant Breeding and Biometry, 252 Emerson Hall, Cornell University, Ithaca, NY 14853-1902, USA, US aut Tanksley S. D. Department of Plant Breeding and Biometry, 252 Emerson Hall, Cornell University, Ithaca, NY 14853-1902, USA, US aut https://doi.org/10.1007/s001220050061 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001220050061 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Monforte A. J. Department of Plant Breeding and Biometry, 252 Emerson Hall, Cornell University, Ithaca, NY 14853-1902, USA, US aut NATIONALLICENCE 700 1- Tanksley S. D. Department of Plant Breeding and Biometry, 252 Emerson Hall, Cornell University, Ithaca, NY 14853-1902, USA, US aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer