Increased micronutrient content (Zn, Mn) in the [3M.sup.b](4B) wheat--Aegilops biuncialis substitution and [3M.sup.b].4BS translocation identified by GISH and FISH

Introduction Micronutrients are essential parts of the human diet, and in some cases the alimentary disorders caused by an insufficient daily intake may lead to serious illnesses. Zinc (Zn) is [...]
[3M.sup.b] Triticum aestivum L. (Mv9kr1)- Aegilops biuncialis Vis. (MvGB642) addition lines were crossed with the Chinese Spring ph1b mutant genotype (CSph1b) to produce [3M.sup.b]-wheat chromosome rearrangements. In the [F.sub.3] generation, [3M.sup.b](4B) substitution lines and [3M.sup.b].4BS centric fusions were identified with in situ hybridization using repetitive and genomic DNA probes, and with SSR markers. Grain micronutrient analysis showed that the investigated Ae. biuncialis accession MvGB382 and the parental line MvGB642 are suitable gene sources for improving the grain micronutrient content of wheat, as they have higher K, Zn, Fe, and Mn contents. The results suggested that the Ae. biuncialis chromosome [3M.sup.b] carries genes determining the grain micronutrient content, as the [3M.sup.b].4BS centric fusion had significantly higher Zn and Mn contents compared with the recipient wheat cultivar. As yield-related traits, such as the number of tillers, the length of main spike, and spikelets per main spike, were similar in the [3M.sup.b].4BS centric fusion and the parental wheat genotype, it can be concluded that this line could be used in pre-breeding programs aimed at enriching elite wheat cultivars with essential micronutrients. Key words: Triticum aestivum, Aegilops biuncialis, [3M.sup.b](4B) substitution, [3M.sup.b].4BS centric fusion, sequential FISH and GISH, grain micronutrient content. Des lignees d'addition [3M.sup.b] Triticum aestivum L. (Mv9kr1)--Aegilops biuncialis Vis. (MvGB642) ont ete croisees avec le mutant Chinese Springph1b (CSph1b) afin de produire des rearrangements chromosomiques [3M.sup.b]-ble. Au sein de la generation [F.sub.3], des lignees de substitution [3M.sup.b](4B) et des fusions centriques [3M.sup.b].4BS ont ete identifiees par hybridation in situ au moyen de sondes d'ADN repete ou genomique ainsi qu'avec des marqueurs SSR. Une analyse de la composition du grain en matiere de micronutriments a montre que l'accession etudiee de l'Ae. biuncialis (MvGB382) et la lignee parentale MvGB642 constituent des sources valables pour ameliorer le contenu en micronutriments chez le ble, du fait qu'elles ont une teneur accrue en K, Zn, Fe et Mn. Ces resultats suggerent que le chromosome [3M.sup.b] de l'Ae. biuncialis porte des genes contribuant a determiner le contenu en micronutriments puisque la fusion centrique [3M.sup.b].4BS presentait un contenu en Zn et en Mn significativement superieur a la variete de ble receptrice. Puisque les composantes de rendement comme le nombre de talles, la longueur de la tige principale et le nombre d'epillets par epi etaient semblables chez la fusion centrique [3M.sup.b].4BS et chez le genotype de ble parental, les auteurs en concluent que cette lignee pourrait s'averer utile dans des programmes de pre-selection visant a accroitre la teneur en micronutriments essentiels chez les cultivars elites de ble. [Traduit par la Redaction] Mots-cles: Triticum aestivum, Aegilops biuncialis, substitution [3M.sup.b](4B), fusion centrique [3M.sup.b].4BS, analyses FISH et GISH sequentielles, teneur en micronutriments chez le grain.