A Robertsonian translocation from Thinopyrum bessarabicum into bread wheat confers high iron and zinc contents

Development of wheat-alien translocation lines has facilitated practical utilization of alien species in wheat improvement. The production of a compensating Triticum aestivum-Thinopyrum bessarabicum whole-arm Robertsonian translocation (RobT) involving chromosomes 6D of wheat and 6E(b) of Th.bessarabicum (2n=2x=14, (EEb)-E-b) through the mechanism of centric breakage-fusion is reported here. An F-2 population was derived from plants double-monosomic for chromosome 6D and 6E(b) from crosses between a DS6E(b)(6D) substitution line and bread wheat cultivar Roushan' (2n=6x=42, AABBDD) as female parent. Eighty F-2 genotypes (L1-L80) were screened for chromosome composition. Three PCR-based Landmark Unique Gene (PLUG) markers specific to chromosomes 6D and 6E(b) were used for screening the F-2 plants. One plant with a T6E(b)S.6DL centric fusion (RobT) was identified. A homozygous translocation line with full fertility was recovered among F-3 families and verified with genomic insitu hybridization (GISH). Grain micronutrient analysis showed that the DS6E(b)(6D) substitution line and T6E(b)S.6DL stock have higher Fe and Zn contents than the recipient wheat cultivar Roushan'.