1. Fine genetic mapping of greenbug aphid-resistance gene Gb3 in Aegilops tauschii.
- Author
-
Azhaguvel, Perumal, Rudd, Jackie, Ma, Yaqin, Luo, Ming-Cheng, and Weng, Yiqun
- Subjects
- *
APHIDS , *GREENBUG , *AEGILOPS , *WHEAT diseases & pests , *PLANT gene mapping , *PESTICIDE resistance , *PLANT chromosomes , *GENETIC markers - Abstract
The greenbug, Schizaphis graminum (Rondani), is an important aphid pest of small grain crops especially wheat ( Triticum aestivum L., 2 n = 6 x = 42, genomes AABBDD) in many parts of the world. The greenbug-resistance gene Gb3 originated from Aegilops tauschii Coss. (2 n = 2x = 14, genome DD) has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. We previously mapped Gb3 in a recombination-rich, telomeric bin of wheat chromosome arm 7DL. In this study, high-resolution genetic mapping was carried out using an F segregating population derived from two Ae. tauschii accessions, the resistant PI 268210 (original donor of Gb3 in the hexaploid wheat germplasm line 'Largo') and susceptible AL8/78. Molecular markers were developed by exploring bin-mapped wheat RFLPs, SSRs, ESTs and the Ae. tauschii physical map (BAC contigs). Wheat EST and Ae. tauschii BAC end sequences located in the deletion bin 7DL3-0.82-1.00 were used to design STS (sequence tagged site) or CAPS (Cleaved Amplified Polymorphic Sequence) markers. Forty-five PCR-based markers were developed and mapped to the chromosomal region spanning the Gb3 locus. The greenbug-resistance gene Gb3 now was delimited in an interval of 1.1 cM by two molecular markers (HI067J6-R and HI009B3-R). This localized high-resolution genetic map with markers closely linked to Gb3 lays a solid foundation for map based cloning of Gb3 and marker-assisted selection of this gene in wheat breeding. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF