Molecular Cytogenetic and Physiological Characterization of a Novel Wheat-Rye T1RS.1BL Translocation Line from Secale cereal L. Weining with Resistance to Stripe Rust and Functional “Stay Green” Trait

Abstract

In this study, a novel T1RS.1BL translocation line RT843-5 was selected from a cross between wheat Mianyang11 (MY11) and Weining rye. The results of MC-FISH, PCR, and A-PAGE showed that RT843-5 contained two intact T1RS.1BL translocation chromosomes. RT843-5 showed resistance to the most virulent and frequently occurring stripe rust races/isolates. Additionally, RT843-5 showed resistance in the field in locations where stripe rust outbreaks have been the most severe in China. Genetic analysis indicated one new gene for stripe rust resistance, located on 1RS of RT843-5, which was tentatively named YrRt843. Furthermore, the chlorophyll content, the activities of catalase (CAT), and superoxide dismutase (SOD), and the net photosynthetic rate (Pn) of RT843-5 were significantly higher than those in its wheat parent MY11, whereas malondialdehyde (MDA) accumulation was significantly lower after anthesis in RT843-5 compared to in MY11. RT843-5 had a significantly higher 1000-kernel weight and yield than MY11. The results indicated that RT843-5 exhibited functional stay-green traits after anthesis, that delayed the senescence process in wheat leaves during the filling stage and had positive effects on grain yield. The present study indicated that Weining rye may carry untapped variations as a potential source of resistance, and that RT843-5 could be an important material for wheat breeding programs in the future.

Permanent Spreading of 1RS.1AL and 1RS.1BL Translocations in Modern Wheat Breeding

“…However, GISH does not show differences between 1RS.1BL and 1RS.1AL translocations as their size and arm ratio are quite similar ( Figure 4 ). For cytogenetic differentiation between them, a FISH procedure with probes such as pSc119.2 and pAs1 should be applied [ 51 , 52 , 53 ].…”

“…Polovchanka was used in the pedigrees of the Veda and Yuka, Knyazhna in the pedigrees of Kuren’ and Vershina, Tanya in the pedigrees of Ol’khon and Gurt, all of the derived cultivars carrying 1RS.1BL. Thus, 1RS of alternative origin is widely involved in the breeding process of winter bread wheat, which contributes to the expansion of the genetic diversity of this crop [ 52 , 53 ].…”