Abstract only

It is now generally accepted that high- molecular weight (HMW) glutenin subunits have the greatest effect on baking quality characteristics (Shewrey et al., 1992). Doubled Haploid (DH) lines are ideal for study the genetic bases of baking quality. In present work twenty (DH) lines of bread wheat derived from Fl and F3 generations and generated using the maize pollen method, (Zenkteler & Nitzsche, 1984) along with their parents and 2 check cultivars were studied for baking properties and HMW glutenin subunits. High molecular weight glutenin subunits (HMW-GS) were separated using SDS-PAGE method (Payne et al.,1981). The relation was evaluated between HMW -subunits and baking quality characteristics such as protein percentage, grain hardness glutin index, valorimetry value and some other traits. Among DH lines, parents and check cultivars, DH line #6 was the best for quality. There were positive and significant correlation between grain hardness (GH) and protein percen- tage (59%), water absorption percentage and grain hardness (57%), arrival time and water absorption percentage (52%), valorimetry value and Gluten percentage ( 62% ), time of dough broker and valorimetry value. On the whole in all analysed samples 11 HMW-G subunits were detected at the three Loci. In particular three at Glu-Al (2*,1 and Null), six at Glu-B1 (7,7+9,7+8, 17+18,13*+16* and 6+8) and two atGlu-D1 (10+5,12+2) were observed. Doubled haploid lines 1,6,7,10, 12,14, 15, 18 and 19 showed better quality scores. In genotype 25 (cultivar 90 Zhong 87) a subunit pair was detected at the Glu-B1locus with slower mobility compared to 13+ 16 and temporarilily was named 13*+ 16*. Mean squares of different quality traits at the three loci were significant. Effect of locus Glu-B1 for protein percentage (1.963**), grain hardness (150.287**), dry gluten (6.131**), zeleny traits recorded by farinograph (31.7 61 *) was significant. Also the effect of locus Glu-D 1 for zeleny Gluten index (44.178*) and grain hardness (59.326*) was significant. A significant effect was observed between the alleles at Glu-A1 locus and grain hardness (171.782**), arrival time (0.953**) and dough development (2.3 73**). At locus Glu-A1 for traits grain hardness, dry gluten and duration of arrival time, difference of effect of allele 2* as compared with two other alleles was significant. For subunit #6, the effect of alleles 1 and 2* on gluten index and dough development comparing to null allele was significantly higher. Allele subunit #7 at Glu-B1 locus showed significant difference with other alleles (6+8,7+8,7+9,3+ 16,7+18). At Glu-D1 locus, subunit 5+ 1O regarding to farinograph zeleny, Gluten index and grain hardness comparing to allele 2+ 12 showed significant difference. Regarding types of alleles, in the 3 gene loci among DH lines and parents there were not any similarity except for line #14.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection