title: Molecular cytogenetic characterization of a new wheat-rye 1BL•1RS translocation line expressing superior stripe rust resistance and enhanced grain yield.
abstract: A new wheat-rye 1BL•1RS translocation line, with the characteristics of superior stripe rust resistance and high thousand-kernel weight and grain number per spike, was developed and identified from progenies of wheat-rye- Psathyrostachys huashanica trigeneric hybrids. The wheat-rye 1BL•1RS translocation line from Petkus rye has contributed substantially to the world wheat production. However, due to extensive growing of cultivars with disease resistance genes from short arm of rye chromosome 1R and coevolution of pathogen virulence and host resistance, these cultivars successively lost resistance to pathogens. In this study, a new wheat-rye line K13-868, derived from the progenies of wheat-rye-Psathyrostachys huashanica trigeneric hybrids, was identified and analyzed using fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH), acid polyacrylamide gel electrophoresis (A-PAGE), and molecular markers. Cytological studies indicated that the mean chromosome configuration of K13-868 at meiosis was 2n = 42 = 0.14 I + 18.78 II (ring) + 2.15 II (rod). Sequential FISH and GISH results demonstrated that K13-868 was a compensating wheat-rye 1BL•1RS Robertsonian translocation line. Acid PAGE analysis revealed that clear specific bands of rye 1RS were expressed in K13-868. Simple sequence repeat (SSR) and rye 1RS-specific markers ω-sec-p1/ω-sec-p2 and O-SEC5'-A/O-SEC3'-R suggested that the 1BS arm of wheat had been substituted by the 1RS arm of rye. At the seedling and adult growth stage, compared with its recurrent wheat parent SM51 and six other wheat cultivars containing the 1RS arm in southwestern China, K13-868 showed high levels of resistance to stripe rust (Puccinia striiformis f. sp. tritici, Pst) pathogens prevalent in China, which are virulent to Yr10 and Yr24/Yr26. In addition, K13-868 expresses higher thousand-kernel weight and more grain number per spike than these controls in two growing seasons, suggesting that this line may carry yield-related genes of rye. This translocation line, with significant characteristics of resistance to stripe rust and high thousand-kernel weight and grain number per spike, could be utilized as a valuable germplasm for wheat improvement.
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Weiliang
authors.initials: W
authors.lastname: Qi
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Daiyan
authors.initials: D
authors.lastname: Li
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Chengdou
authors.initials: C
authors.lastname: Diao
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Xu
authors.affiliation: College of Resources, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Fan
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Sha
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Haiqin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Youliang
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, 211 Huimin Road, Wenjiang, Chengdu, 611130, Sichuan, China. houyang.kang@sicau.edu.cn.
authors.forename: Houyang
authors.initials: H
authors.lastname: Kang
mesh_terms: D060467:Disease Resistance / Q000235:genetics*; D005819:Genetic Markers; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis; D010935:Plant Diseases / Q000382:microbiology; D012434:Secale / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D014178:Translocation, Genetic; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology
chemical_list: D005819:Genetic Markers
keywords: 1BL•1RS translocation line; Grain number per spike; Sequential FISH and GISH; Stripe rust resistance; Thousand-kernel weight