1. Early-generation germplasm introgression from Sorghum macrospermum into sorghum (S. bicolor)
- Author
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Kuhlman, Les C., Burson, Byron L., Stelly, David M., Klein, Patricia E., Klein, Robert R., Price, H.J., and Rooney, William L.
- Subjects
Sorghum -- Growth -- Genetic aspects -- Research ,Plant cytogenetics -- Research -- Growth -- Genetic aspects ,Embryonic development -- Genetic aspects -- Growth ,Hybridization -- Research -- Growth -- Genetic aspects ,Germ cells -- Genetic aspects -- Growth -- Research ,Company growth ,Biological sciences - Abstract
Sorghum has been improved by public and private breeding programs utilizing germplasm mostly from within the species Sorghum bicolor. Recently, hybridization with an Australian species, S. macrospermum ([AAB.sub.1][B.sub.1] YYZZ), has been demonstrated and the genomic relationship to S. bicolor ([AAB.sub.1][B.sub.1]) shown to be partially compatible. For this species to be potentially useful to sorghum improvement programs, there must be documented introgression into an S. bicolor background. Fifteen [BC.sub.1][F.sub.1] progeny were recovered using the interspecific hybrid as a female and embryo rescue. In these progeny, chromosome numbers ranged from 35 to 70 and all were essentially male-sterile. Repeated backcrossing with 5. bicolor pollen produced [BC.sub.2][F.sub.1] seed on 3 of the 15 [BC.sub.1][F.sub.1] plants. [BC.sub.2][F.sub.1] progeny had varying levels of male fertility; selfed seed set ranged from 0% to 95%, with only 2 individuals being completely male-sterile. Using AFLP and SSR markers, genomic introgression of $. macrospermum ranged from 0% to 18.6%. Cytogenetic analysis of 19 individuals revealed that chromosome numbers were 20, except for a single backcross that had 21 chromosomes. Molecular cytogenetic analysis confirmed the presence of recombinant introgression chromosomes as well as alien addition and alien substitution chromosomes within the [BC.sub.2][F.sub.1s]. Key words: Sorghum bicolor, introgression, fluorescent in situ hybridization, genomic in situ hybridization. Sorghum macrospermum. Le sorgho a fait l'objet de travaux d'amelioration genetique tant publics que prives en utilisant prineipalement les ressources genetiques disponibles au sein de l'espece Sorghum bicolor. Recemment, l'hybridation avec une espece australienne, S. macrospermum ([AAB.sub.1][B.sub.1] YYZZ), a ete demontree et la relation genomique au S. bicolor ([AAB.sub.1][B.sub.1]) s'est averee partiellement compatible. Pour que cette espece soil potentiellement utile dans des programmes d'amelioration du sorgho, il doit y avoir introgression documentee au sein du genome du S. bicolor. Quinze progenitures [BC.sub.1][F.sub.1] ont ete obtenues en employ ant l'hybride interspecifique comme femelle et le sauvetage d'embryons. Au sein de cette descendance, le nombre de chromosomes variait entre 35 et 70 et tous les individus etaient essentiellement androsteriles. Des retrocroisements repetes avec le pollen du S. bicolor ont permis d'obtenir des grains BC2F1 sur 3 des 15 plants [BC.sub.1][F.sub.1]. La progeniture [BC.sub.2][F.sub.1] presentait divers degres d'androsterilite ; le succes en autofecondation variait entre 0 et 95 %, avec deux individus completement androsteriles. A l'aide de marqueurs AFLP et SSR, I'introgression genomique du S. macrospermum variait entre U et 18,6 %. Une analyse cytogenetique sur 19 individus a revele la presence de 20 chromosomes, sauf pour un retrocroisement oil il y avait 21 chromosomes. Une analyse cytogenetique moleculaire a confirme la presence de chromosomes recombinants dotes d'introgressions lout comme des lignees d'addilion el de substitution ehromosomique au sein des [BC.sub.2][F.sub.1]. Mors-cies : Sorghum bicolor, introgression. hybridation in situ en fluorescence, hybridation genomique in situ, Sorghum macrospermum. [Traduit par la Redaction], Introduction Sorghum (Sorghum bicolor (L.) Moench) is an important food and feed crop around the world. The 2006 US grain sorghum crop was valued at approximately $715 million (USDA, NASS [...]
- Published
- 2010
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