Among various functional genomics tools used to characterize genes in plants, transposonbased mutagenesis approaches offer great potential, especially in barley and wheat, which possess large genomes and in which gene...Among various functional genomics tools used to characterize genes in plants, transposonbased mutagenesis approaches offer great potential, especially in barley and wheat, which possess large genomes and in which genetic transformation is not routine. Two Ds transposon flanking sequences(TNPs), TNP-29(27.4 c M(centi Morgan)) and TNP-79(70.3 c M), were mapped in the vicinity of a malting quality QTL located on chromosome 4H of barley. Reactivation of the Ds transposon sequence from these TNP lines led to the identification of genes in the malting QTL regions. Several Ds(dissociation) lines were generated by crossing TNP-29 and TNP-79 with an Ac TPase(activator) expressing line(25-B), and F2 progenies were subsequently screened for Ds insertions at new locations. To further characterize these Ds mutants, we mapped the new Ds flanking sequences on a barley genetic map and found that 29% of Ds were located in regions associated with the malting QTL located on chromosome 4H and in close proximity to other important malting-associated QTL across the barley chromosome. Using a sequence based approach, a linkage map was generated that confirmed the position of Ds loci in the barley genome map. Locating these Ds loci on the barley map opens avenues to dissect important malting QTL for facilitating identification of candidate malting genes.展开更多
There is limited genetic mapping data useful for breeding programs of watermelon. Introgression lines should be a use-ful tool for genetic studies and genetic enhancement of watermelon cultivars. In this study, we use...There is limited genetic mapping data useful for breeding programs of watermelon. Introgression lines should be a use-ful tool for genetic studies and genetic enhancement of watermelon cultivars. In this study, we used an advanced re-combinant population (BC2F2) to identify and map chromosomal segments of the wild watermelon Citrullus lanatus var. citroides that were incorporated in the genome of the watermelon cultivar Crimson Sweet (Citrullus lanatus var. lana-tus). An advanced recombinant population (BC2F2) was constructed using a United States Plant Introduction (PI) 494817 (C. lanatus var. citroides) (known to have moderate resistance to bacterial fruit blotch) as a donor parent, and the elite watermelon cultivar Crimson Sweet (C. lanatus var. lanatus) as the recurrent parent. The genetic linkage map consists of 272 markers, including 89 sequence-related amplified polymorphism (SRAP), 72 targeted region amplifica-tion polymorphism (TRAP), and 111 high frequency oligonucleotide-targeting active gene (HFO-TAG) markers. The 272 markers were assembled into 51 linkage groups, covering a total genetic distance of 2162 cM, with an average genetic distance of 7.9 cM between markers. Also, we expended the genetic linkage map for watermelon derived from a testcross population {Griffin 14113 [C. lanatus var. citroide (L.H. Bailey) Mansf.] x watermelon cultivar New Hamp-shire Midget (C. lanatus var. lanatus)} x PI 386015 [C. colocynthis (L.) Schrad.]. The genetic linkage map based on the test cross population consists of 558 markers that cover a genetic distance of 2760.8 cM. This linkage map consists of 41 linkage group, including 10 large linkage groups (ranging from102-240 cM), nine intermediate size linkage groups (ranging from 62-93 cM), and 22 small linkage groups (ranging from 2-56 cM). Comparative mapping between these two linkage maps identified high consensus in 25 HFO-TAG markers and one TRAP marker that represent 8 linkage groups in the BC2F2 population and 9 linkage groups in the testcross population. These results indicate that HFO-TAG markers should be useful in comparative mapping. The extended genetic maps and the genetic population in this study should be useful in breeding programs using marker assisted selection and should serve as a platform for further de-velopment of introgression lines for watermelon.展开更多
基金Funding for this project was provided by Barley Malting and Brewing Research Institute (grant number: 217248)
文摘Among various functional genomics tools used to characterize genes in plants, transposonbased mutagenesis approaches offer great potential, especially in barley and wheat, which possess large genomes and in which genetic transformation is not routine. Two Ds transposon flanking sequences(TNPs), TNP-29(27.4 c M(centi Morgan)) and TNP-79(70.3 c M), were mapped in the vicinity of a malting quality QTL located on chromosome 4H of barley. Reactivation of the Ds transposon sequence from these TNP lines led to the identification of genes in the malting QTL regions. Several Ds(dissociation) lines were generated by crossing TNP-29 and TNP-79 with an Ac TPase(activator) expressing line(25-B), and F2 progenies were subsequently screened for Ds insertions at new locations. To further characterize these Ds mutants, we mapped the new Ds flanking sequences on a barley genetic map and found that 29% of Ds were located in regions associated with the malting QTL located on chromosome 4H and in close proximity to other important malting-associated QTL across the barley chromosome. Using a sequence based approach, a linkage map was generated that confirmed the position of Ds loci in the barley genome map. Locating these Ds loci on the barley map opens avenues to dissect important malting QTL for facilitating identification of candidate malting genes.
文摘There is limited genetic mapping data useful for breeding programs of watermelon. Introgression lines should be a use-ful tool for genetic studies and genetic enhancement of watermelon cultivars. In this study, we used an advanced re-combinant population (BC2F2) to identify and map chromosomal segments of the wild watermelon Citrullus lanatus var. citroides that were incorporated in the genome of the watermelon cultivar Crimson Sweet (Citrullus lanatus var. lana-tus). An advanced recombinant population (BC2F2) was constructed using a United States Plant Introduction (PI) 494817 (C. lanatus var. citroides) (known to have moderate resistance to bacterial fruit blotch) as a donor parent, and the elite watermelon cultivar Crimson Sweet (C. lanatus var. lanatus) as the recurrent parent. The genetic linkage map consists of 272 markers, including 89 sequence-related amplified polymorphism (SRAP), 72 targeted region amplifica-tion polymorphism (TRAP), and 111 high frequency oligonucleotide-targeting active gene (HFO-TAG) markers. The 272 markers were assembled into 51 linkage groups, covering a total genetic distance of 2162 cM, with an average genetic distance of 7.9 cM between markers. Also, we expended the genetic linkage map for watermelon derived from a testcross population {Griffin 14113 [C. lanatus var. citroide (L.H. Bailey) Mansf.] x watermelon cultivar New Hamp-shire Midget (C. lanatus var. lanatus)} x PI 386015 [C. colocynthis (L.) Schrad.]. The genetic linkage map based on the test cross population consists of 558 markers that cover a genetic distance of 2760.8 cM. This linkage map consists of 41 linkage group, including 10 large linkage groups (ranging from102-240 cM), nine intermediate size linkage groups (ranging from 62-93 cM), and 22 small linkage groups (ranging from 2-56 cM). Comparative mapping between these two linkage maps identified high consensus in 25 HFO-TAG markers and one TRAP marker that represent 8 linkage groups in the BC2F2 population and 9 linkage groups in the testcross population. These results indicate that HFO-TAG markers should be useful in comparative mapping. The extended genetic maps and the genetic population in this study should be useful in breeding programs using marker assisted selection and should serve as a platform for further de-velopment of introgression lines for watermelon.
