Browsing by Author "Scoles, G.J."
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Item Developing markers for canola seed quality – relationship of seedcoat colour and lignin content in Brassica carinata.(1998-02-19) Marles, M.A.S.; Gruber, M.Y.; Scoles, G.J.; Rakow, G.F.W.Item Low-lignin hull in oat(2002-02-20) Williams, S.K.; Rossnagel, B.G.; Scoles, G.J.The use of whole oat in feed rations is restricted due to low digestibility of the hull. AC Assiniboia hulls have decreased acid detergent lignin (ADL) content. AC Assiniboia was crossed with OT 775 and the resulting lines were measured for ADL content. The ratio of F4:5 lines with low to normal ADL concentration fit a 1:1 genetic ratio. Indicating that the low-lignin trait is controlled by a single major gene. ADL concentration was correlated with hull colour and acid detergent fiber concentration. ADL concentration was not correlated with the protein or fat concentration of the groat. Simple inheritance of the low-lignin trait indicates that it can be incorporated into the oat breeding program. Furthermore, ADL concentration is not correlated with groat fat so a cultivar with a low lignin hull and high fat groat can be developed.Item Molecular marker assisted introgression of loose and covered smut resistance into CDC McGwire hulless barley(2005-02-17) Grewal, T.S.; Rossnagel, B.G.; Scoles, G.J.CDC McGwire is a high yielding hulless barley cultivar from the Crop Development Centre (CDC), University of Saskatchewan which is susceptible to both true loose and covered smut. Screening for these diseases is time, labour and space consuming and escapes are very frequent making it necessary to screen putative resistant lines several times to confirm resistance. In addition, both the diseases are expressed in the inflorescence, simultaneous screening for them is not possible. Molecular Marker Assisted Selection (MAS) is a good alternative to combine the resistance to both diseases in the same line. Sequence characterized amplified region (SCAR) markers linked to the loose smut resistance gene Run8 (Eckstein et al. 2002) and covered smut resistance gene Ruhq (Ardiel et al. 2002, Grewal et al. 2004) have been developed at the CDC and a program was initiated to introgress loose smut resistance (Run8) and covered smut resistance (Ruhq) into CDC McGwire using MAS. Loose smut resistance was transferred from TR251 (Run8) and covered smut resistance from either Q21861 or TR640 (Ruhq). Two strategies (doubled haploidy and marker-assisted backcrossing) were used to introgress both resistance genes. Screening 35 microspore culture derived doubled haploid (DH) lines against covered and loose smut in the field and greenhouse showed that in most lines, the phenotype defined by disease reactions and genotype defined by the SCAR markers agreed. Screening putative resistant lines three times for covered and loose smut identified 12 DH lines resistant to both smuts and positive to molecular markers of both the diseases. In the marker-assisted backcross program, plants were genotyped in each generation and plants positive for both markers were backcrossed to CDC McGwire. The genotyping of BC1F1, BC2F1 and BC3F1 plants with SCAR markers (UhR450 and Un8700R) showed a 1:2:2:1 segregation indicating the presence of two major genes. Twenty BC3F3 lines (10 lines selected with the covered smut resistance from Q21861 and 10 lines selected with the covered smut resistance from TR640) were evaluated for covered smut reaction in the field in 2004 and in the greenhouse in the fall of 2004. All lines showed resistance to covered smut. BC3F3 lines were inoculated with loose smut in the field in 2004 and evaluated in the greenhouse. Eighteen of 20 lines showed loose smut resistance. These putative double resistant lines will be phenotyped in BC3F5 generations to confirm disease reactions. These results confirm that molecular markers can assist in rapid introgression of simply inherited disease resistance genes into elite lines with considerable savings in time and cost.Item New sources of scald (Rhynchosporium secalis Davis) resistance for western Canadian barley(2001-02-22) Singh, A.K.; Rossnagel, B.G.; Scoles, G.J.Scald, caused by Rhynchosporium secalis Davis, is an important fungal foliar disease of barley which can cause significant losses of yield and quality in western Canada. Scald can be controlled by fungicides and/or cultural methods, however, the use of genetic resistance is most desirable control strategy. The objectives of this study were to evaluate scald resistance in two New Zealand barley genotypes; to study the inheritance of that resistance and to test its novelty relative to a number of existing resistance sources available to Canadian breeding programs. New Zealand genotypes 145L2 and 4176/n, which showed scald resistance in NZ nurseries and in Alberta scald screening nurseries in 1998, were evaluated in 1999 and 2000 Alberta nurseries. To determine the genetic control of resistance, these resistant lines were each crossed with scald susceptible CDC McGwire; and resistant versus susceptible progeny ratios from F2 populations and F5 recombinant inbred lines (RILs) were tested for chi-square goodness of fit for one or two gene control. To determine the source of the resistance, ‘known’ H. vulgare parents of these NZ lines were evaluated in the Alberta scald nurseries. In addition, 145L2 was crossed with 4176/n and four local resistant lines to determine allelic relationships between ‘145L2’ resistance and the resistance in the local lines. In 1999 and 2000, both NZ lines expressed good scald resistance. Inheritance studies indicated that resistance in both NZ lines is governed by a single dominant gene. ‘145L2’ resistance is different from resistance in 4176/n and the other barley lines tested. All ‘known’ progenitors of these lines were susceptible suggesting that resistance is a result of mutation and/or introgression(s) from what is described as an ‘unknown’ parent in their pedigrees. The NZ lines provide new sources of scald resistance that can be incorporated into local breeding lines.