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P8810-B5B3A2A2 (Reg. no. GP-618, PI 600683) white spring wheat (Triticum aestivum L.) was released in 1998 by the Agriculture and Agri-Food Canada (AAFC), Semiarid Prairie Agricultural Research Centre in Swift [...]

P8901-AP1A2B1B (Reg. no. GP-723, PI 613175) and P8901-AQ1A2B1B (Reg. no. GP-724, PI 613176) hard red spring wheat lines (Triticum aestivum L.), were released in 2000 by Agriculture and Agri-Food Canada [...]

Loose smut [Ustilago tritici(Pers) Rostr.] of wheat (Triticum aestivumL) causes losses in grain yield roughly proportional to the incidence of the disease. Efforts to control this disease utilizing genetic resistance are being made in breeding programmes around the world. DNA markers for genetic resistance would greatly enhance breeding efforts by reducing the substantial time and labour resources necessary to screen for resistant lines using traditional inoculation methods. The objective of this study was to identify DNA markers associated with resistance. Doubled haploid progeny from the four crosses ‘Glenlea’/‘AC Taber’, ‘SC8021V2’/‘AC Karma’, ‘Diamant’/TD12A, and 9340-CP*/‘AC Vista’ were evaluated with individual races ofU. triticiand simple sequence repeat markers. Simple interval mapping was performed using MQTL software and single point analysis. ‘Glenlea’, which has complete and broad resistance to all known races ofU. triticiin Canada, contributed a QTL for resistance to races T2, T10, T15, T19 and T39 atXwmc160on chromosome 5B. ‘Glenlea’ also contributed QTL for resistance to races T2, T9 and T15 atXgwm302on chromosome 7B and to races T9, T19 and T39 on chromosome 3A at markerXwmc559. The chromosome 5B QTL from ‘Glenlea’ coincided with a race T39 resistance locus from ‘AC Karma’. The 7B QTL from ‘Glenlea’ coincided with resistance to race T9 from 9340-CP* and T2, T9 and T27 resistance from TD12A. The QTL on 3A from ‘Glenlea’ was coincidental with T9 resistance from 9340-CP*. When evaluated with race T10, a QTL was identified nearXbarc183on chromosome 6D from ‘SC8021V2’. A QTL to race T9 from ‘SC8021V2’ within the intervalXcfa2019toXgwm344awas identified on 7A. A third QTL from ‘SC8021V2’ was located on 6B atXbarc223andXbarc332b.The chromosome 5B locus together with either the 7A or 7B genetic loci would provide resistance to predominant races of loose smut found on the Canadian prairies. [ABSTRACT FROM AUTHOR]

Common bunt, caused byTilletia tritici(Bjerk.) G. Wint. in Rabenh. andT. laevisKϋhn in Rabenh., is an economically important disease of wheat (Triticum aestivumL.) worldwide. The hexaploid wheat cultivar ‘McKenzie’ possesses effective resistance against known races of common bunt in western Canada. Understanding the nature of this resistance through DNA marker mapping will be useful for breeding. Disease reaction toT. triticirace T19 andT. laevisrace L16 from field tests was analysed with simple sequence repeat markers for 174 doubled haploid lines using interval mapping. MarkersXgwm573andXwmc17, located on wheat chromosome 7B, were strongly associated with the resistance. The quantitative trait locus was designatedQCbt.spa-7B.1. The markers were validated on two other populations in which ‘McKenzie’ was in the parentage. The markers will be useful in breeding as a tool for selecting for common bunt resistance from ‘McKenzie’ and will assist in identifying the resistance among potential new sources. [ABSTRACT FROM AUTHOR]