Registration of sawfly resistant hexaploid spring wheat germplasm lines derived from durum.
The backcrossed seed from the solider and more fertile plants were increased in a growth cabinet and scored for pith development. Each internode of the primary wheat culm was sliced longitudinally and rated for the degree of pith development in the stem lumen on a scale of 1 to 5 (Clarke et al., 1998). Seed from the solider, more fertile B[C.sub.1][F.sub.2] lines were grown in the field in 1998 and scored for solidness. Single B[C.sub.1][F.sub.3] selections were made on the basis of criteria of stem solidness, spike fertility, glume color and disarticulation, and time to maturity. These selections were grown as B[C.sub.1][F.sub.4] head rows in the 1999 field sawfly (Cephus cinctus Nort.) nursery, wherein plots are seeded next to undisturbed stubble containing sawfly pupae from the previous growing season. G9608B1-L12J11BF02 and G9608B1-L12J13AU01 derive from B[C.sub.1][F.sub.4] selections made in the 1999 sawfly nursery. The B[C.sub.1][F.sub.4] rows had 2% wheat stem sawfly cutting compared to 84% for the hollow check 'Glenlea' (Evans et al., 1972), 44% for the wheat stem sawfly resistant hexaploid check 'AC Abbey' (DePauw et al., 2000), and 13% for Golden Ball. Both germplasm lines have very solid stems with all stem internodes of G9608B1-L12J11BF02 and G9608B1-L12J13AU01 completely filled with pith (score of 5.0 [+ or -] 0). Pith development was similar to Golden Ball (4.6 [+ or -] 0.2) and considerably better than the sawfly resistant lines derived from the S-615 source (DePauw et al., 1995) such as AC Abbey (2.7 [+ or -] 0.3) and 'AC Eatonia' (DePauw et al., 1994) (3.0 [+ or -] 0.5). Stem solidness of the B[C.sub.1][F.sub.7] selections were evaluated in the field in 2001. The average pith development over all internodes was 4.8 [+ or -] 0.4 for G9608B1-L12J11BF02 and 4.8 [+ or -] 0.6 for G9608B1-L12J13AU01.
This first backcross germplasm is not as agronomically unsuitable as the synthetic hexaploid parent. These two lines stood out in the B[C.sub.1][F.sub.7] test for their uniformity, fertility, and ease that the seed could be thrashed. However, both lines are still taller and later maturing than AC Elsa, which averages 95 cm and ranges in maturity from 104 d in the Brown soil zones to 107 d in the Dark Brown soil zones (Clarke et al., 1997). The vast majority of the culled lines were extremely variable within the rows and produced very little to no seed. Cytological instability was observed in some of the progeny from the initial crosses with the synthetic hexaploid parent (data not shown). We do not know the genetics of this source of solidness in a hexaploid background, so chose to register two lines since they may carry different combinations of the genes involved. Investigation of the genetics of the pith expression is underway.
These lines will be useful for development of solid-stemmed wheat cultivars that have resistance to the wheat stem sawfly and have an ancestry different from S-615. Small quantities of seed are available on request from the corresponding author.
Clark, J.A., C.R. Ball, and J.H. Martin. 1922. Classification of American wheat varieties. Bull. 1074. USDA, Washington, DC.
Clarke, F.R., T. Aung, and R.M. DePauw. 1998. Simplifying the inheritance of resistance to wheat stem sawfly (Cephus cinctus Nort.). p. 240-242 In A.E. Slinkard (ed.) Proc. 9th Int. Wheat Genetics Symp., Vol. 3. Printcrafters Inc., Winnipeg, MB, Canada.
Clarke, J.M., R.M. DePauw, T.N. McCaig, M.R. Fernandez, R.E. Knox, and J.G. McLeod. 1997. AC Elsa hard red spring wheat. Can. J. Plant Sci. 77:661-663.
DePauw, R.M., G.R. Boughton, and D.R. Knott. 1995. Hard Red Spring Wheat. p. 1-31 In A.E. Slinkard and D.R. Knott (ed.) Harvest of gold: The history of field crop breeding in Canada. University Extension Press, Saskatoon, SK, Canada.
DePauw, R.M., J.M. Clarke, R.E. Knox, M.R. Fernandez, T.N. McCaig, and J.G. McLeod. 2000. AC Abbey hard red spring wheat. Can. J. Plant Sci. 80:123-127.
DePauw, R.M., J.G. McLeod, J.M. Clarke, T.N. McCaig, M.R. Fernandez, and R.E. Knox. 1994. AC Eatonia hard red spring wheat. Can. J. Plant Sci. 74:821-823.
Evans, L.E., L.H. Shebeski, R.C. McGinnis, K.G. Briggs, and D. Zuzens. 1972. Gleanlea red spring wheat. Can. J. Plant Sci. 52:1081-1082.
Kemp, H.J. 1934. Studies of solid stem wheat varieties in relation to wheat stem sawfly control. Sci. Agric. 15:30-38.
F.R. CLARKE, * R.M. DEPAUW, AND T. AUNG
F.R. Clarke and R.M. DePauw, Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Box 1030, Swift Current, Saskatchewan, Canada S9H 3X2; T. Aung, Cereal Research Centre, Agriculture and Agri-Food Canada, 195 Dafoe Road, Winnipeg, MB, Canada R3T 2M9. Registration by CSSA. Accepted 31 Jan. 2005. * Corresponding author (email@example.com).
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|Title Annotation:||REGISTRATIONS OF GERMPLASMS|
|Author:||Clarke, F.R.; DePauw, R.M.; Aung, T.|
|Date:||Jul 1, 2005|
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