Introgression and Characterization of a Goatgrass Gene for a High Level of Resistance to Ug99 Stem Rust in Tetraploid Wheat

G3: Genes, Genomes, Genetics

Shiaoman Chao¹  Daryl L. Klindworth¹  Xiwen Cai³  Zhixia Niu¹  Yue Jin²  Steven S. Xu¹  Justin D. Faris¹  Timothy L. Friesen¹ 

[1] USDA–ARS, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765USDA–ARS, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765USDA–ARS, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765;USDA–ARS Cereal Disease Laboratory, St. Paul, Minnesota 55108USDA–ARS Cereal Disease Laboratory, St. Paul, Minnesota 55108USDA–ARS Cereal Disease Laboratory, St. Paul, Minnesota 55108;Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050

关键词: wheat;    Ug99;    Sr47;    Aegilops speltoides;    chromosome engineering;   

DOI  :  10.1534/g3.112.002386

学科分类：生物科学（综合）

来源: Genetics Society of America

【 摘 要 】

The transfer of alien genes to crop plants using chromosome engineering has been attempted infrequently in tetraploid durum wheat (Triticum turgidum L. subsp. durum). Here, we report a highly efficient approach for the transfer of two genes conferring resistance to stem rust race Pgt-TTKSK (Ug99) from goatgrass (Aegilops speltoides) to tetraploid wheat. The durum line DAS15, carrying the stem rust resistance gene Sr47 derived from Ae. speltoides, was crossed, and backcrossed, to durum 5D(5B) aneuploids to induce homeologous pairing. After a final cross to ‘Rusty’ durum, allosyndetic recombinants were recovered. The Ae. speltoides chromosomal segment carrying Sr47 was found to have two stem rust resistance genes. One gene conditioning an infection type (IT) 2 was located in the same chromosomal region of 2BS as Sr39 and was assigned the temporary gene symbol SrAes7t. Based on ITs observed on a diverse set of rust races, SrAes7t may be the same as Sr39. The second gene conditioned an IT 0; and was located on chromosome arm 2BL. This gene retained the symbol Sr47 because it had a different IT and map location from other stem rust resistance genes derived from Ae. speltoides. Allosyndetic recombinant lines carrying each gene on minimal alien chromosomal segments were identified as were molecular markers distinguishing each alien segment. This study demonstrated that chromosome engineering of Ae. speltoides segments is feasible in tetraploid wheat. The Sr47 gene confers high-level and broad spectrum resistance to stem rust and should be very useful in efforts to control TTKSK.

【 授权许可】

Unknown