Milling and baking quality of flours from 1B·1R soft red winter wheat.

J.M. Johnson, C.A. Griffey, and C.H. Harris.

Soft red winter wheats with chromosome 1 of rye translocated with chromosome 1B, hereafter referred to as 1B·1R, were grown in two locations (Blacksburg and Warsaw, Virginia) during the 1993-94 and 1994-95 seasons. The grain was harvested, cleaned, and tempered to 14 % moisture for milling. The flour was milled in a Brabender Quadramat Junior and stored in plastic bags for testing. Experimental wheats with 1B·1R were compared with control varieties lacking 1B·1R for grain and flour protein content (Kjeldahl method using 5.7 % as the factor), flour yield (first-run flour), mixing time stability (time required to reduce to a specific torque), mixing tolerance index (amount of breakdown after 5 minutes of mixing), and the cookie spread baking test.

Cultivars lacking 1B·1R and selected as controls were Saluda, FFR-555W, Massey, and VA 93-54-209. Experimental varieties with 1B·1R were VA93-54-241 (Massey*5/Balkan), VA93-54-258 (complex pedigree), VA92-52-22 (Tyler//Wheeler/Balkan), VA93-54-185 (Wheeler/3/Massey*3/Balkan//Saluda), VA93-52-55 (Massey*3/Balkan//Saluda), and VA93-54-211. The lines VA93-54-209, without 1B·1R, and VA93-54-211, with 1B·1R, are sister lines derived from the cross `Massey/3/Massey*3/Balkan//Saluda'.

The presence of the 1B·1R translocation in the experimental wheats was confirmed by SDS-PAGE and an immunoassay. The SDS-PAGE and the immunoassay tests were in agreement with the determination of the presence or absence of the chromosome. All experimental varieties tested positive for 1B·1R from both years and locations.

Results. Moisture contents of the experimental and control grains were significantly different among varieties, but no consistent trend occurred between those with and without 1B·1R. The same results were noted for the protein contents of the grain and the flour. Although statistical differences occurred, the differences were not considered to be of practical significance. The control and experimental wheats grown in Blacksburg during 1994-95 had the highest protein content of both locations and years suggesting a factor of environment and not the presence or absence of 1B·1R.

For the group, the yield of flour from the grain also was not affected by the presence or absence of 1B·1R. However, when the pair of sister lines was compared, the flour yield from VA93-54-211 with 1B·1R was significantly lower than that of VA93-54-209, which lacks 1B·1R. This was not explained by protein contents, because they were not the same both years at both locations. Some other factor such as ease of separation of the aleurone layer or bran may be responsible for the difference in flour yield of the 1B·1R lines.

Mixing time stability is the amount of time required for the dough to fall below 500 Brabender units, with longer time indicating a stronger and more tolerant dough to mixing. No trend was seen when those varieties with and without 1B·1R were compared. However, with the exception of the 1993-94 samples grown in Blacksburg, the stability of the dough from flour of VA93-54-211 with 1B·1R was significantly greater than that of VA93-54-209 lacking 1B·1R.

Mixing tolerance index of the dough, the measure of the decline in Brabender units after 5 minutes of mixing, also was not related to the presence or absence of 1B·1R when all varieties were compared. However, when the sister lines alone were compared, the dough made from the flour of VA93-54-211 was significantly more tolerant than that of VA93-54-209.

As a group, the differences in spread between the cookies made with flour from varieties with and without 1B·1R were inconsistent. Comparison of the sister lines indicated a significantly greater cookie spread when flour from VA93-54-209 without 1B·1R was used.

Conclusions. In general, the performance of flours from 1B·1R grains and the flours from control grains was not practically different for all varieties. Specific differences would appear to be more of a function of environment and perhaps genetic background than the presence or absence of 1B·1R per se. A comparison of two varieties that were sister lines with and without 1B·1R inferred that the presence of 1B·1R reduced flour yield, increased the stability and tolerance of the dough made from the flour, and reduced cookie spread. The 1B·1R lines VA93-54-185, VA93-54-258, and VA92-52-22 had flour yields that were similar to those of the control varieties lacking 1B·1R. The lines VA93-54-185 and VA93-54-258 also had cookie spread scores that were similar to those of the control varieties.

Although the results of the testing of flours from grain with and without 1B·1R did show significant differences, the differences were not of a magnitude to make major differences in performance. The one exception may be the reduced flour yield noted when only the sister lines were compared. Comparison of the sister lines indicated that greater tolerance and stability of the dough could be `trade-offs' for lower flour yield. The 1B·1R soft red winter wheats offer promise of producing flour that is of the same, or in some cases superior, quality compared to that of flour from grains without the translocation.

Publications.

Chung YS and Griffey CA. 1995. Powdery mildew resistance in winter wheat. I. Gene number and mode of inheritance. Crop Sci 35:378-382.

Chung YS and Griffey CA. 1995. Powdery mildew resistance in winter wheat. II. Identity of resistance genes. Crop Sci 35:383-388.

Das MK and Griffey CA. 1995. Gene action for adult-plant resistance to powdery mildew in wheat. Genome 38:277-282.

Starling TM, Griffey CA, Price AM, Vanlandingham KS, Sisson WL, and Brann DE. 1996. Registration of `Jackson' wheat. Crop Sci 36:1074-1075.


WASHINGTON

WHEAT GENETICS, QUALITY, PHYSIOLOGY AND DISEASE RESEARCH, USDA-ARS

Department of Crop & Soil Sciences and Plant Pathology, Washington State University, Pullman, WA 99164, USA

R.E. Allan, R.F. Line, M.K. Walker-Simmons, C.F. Morris, J.A. Pritchett, L.M. Little, L.D. Holappa, H.C. Jeffers, A.D. Bettge, D.A. Engle, M.L. Baldridge, B.S. Patterson, R.L. Ader, D.A. Wood, and D.J. Somers.

Utility of semidwarf genes.

The Rht8 Balkan semidwarf may prove to be very useful in developing club wheat varieties for low rainfall areas of the Pacific Northwest (PNW) where the cultivar Moro is adapted. Moro has remained popular in this region because of its outstanding emergence ability. Our results have shown conclusively that the Rht8 gene does not adversely effect emergence as do Rht1 and Rht2. Several club selections with Rht8 had plant heights similar to Tres (an Rht2 semidwarf) and were equal to Moro for emergence rate, percent stand, and coleoptile length. These lines outyielded Moro by 15-30 % in our 1995 trials.

The Rht12 gene of the cultivar Karkagi may warrant use in specific wheat production situations in the PNW. This gene reduces plant height by 40 % in non-semidwarf cultivars and 30 % in semidwarf cultivars. The Rht12 gene enhanced yields by 20 % in cultivars that are prone to lodging such as Moro and Brevor, and reduced yields by about 15 % in Nugaines and Daws, which are Rht2 semidwarfs and not prone to lodging. Importantly, the Rht12 gene does not adversely effect emergence. The gene also delays heading 5 to 8 days in our studies.

The Rht3 gene does not appear to have breeding potential for PNW production environments. Although the gene reduced plant heights by 40 to 50 %, it reduced yields dramatically as well. Yield reductions ranged from 17-45 % in non-semidwarf genetic backgrounds and 45-55 % in Rht2 semidwarf genetic backgrounds.

Conversion of winter wheats to spring growth habits.

Preliminary data were obtained on comparing the grain-yield potentials of four spring growth-habit Vrn genes, when each was transferred into the genetic backgrounds of several PNW winter wheat varieties. In 1995 spring-sown tests at Pullman, their ranking for yield potential (high to low) was Vrn1, Vrn3, Vrn2, and Vrn4. Differences were noted among some of the winter wheat genetic backgrounds. Among winter club wheats, Vrn1 and Vrn3 gave the highest yields in Tres, whereas Vrn1 and Vrn4 produced the highest yields in the Paha background. In soft white winter common backgrounds, Vrn1 and Vrn2 produced high yields in Stephens, whereas Vrn3 gave the highest yield in Daws. The Vrn1, Vrn2, and Vrn3 genes all gave similar yield potentials from spring seeding when placed in Wanser, a hard red winter variety.

We are continuing to compile data on quality of winter vs spring near-isogenic lines (NILs). Autumn seeding of Marfed winter (vrn1) vs spring (Vrn1) NILs indicated that the winter NILs have slightly higher protein contents, absorption levels, and mixing times than their spring counterparts. The winter NILs had softer kernel textures than their spring counterparts. The differences may be due to linkage drag because the sources of the vrn1 allele in these NILs are Korean and Japanese bread wheats.

Heritibility of grain dormancy.

Grain dormancy is the main component controlling preharvest sprouting in white-grained wheats. The white grain sources that we are using are the cultivars Brevor, Clark's Cream, and Losprout. We completed heritability studies involving crosses of these three sources into Greer, a soft white winter wheat that exhibits very low dormancy. Parent/offspring h2 values ranged from 0.28 to 0.54, with the lowest value for the `Brevor/Greer' population and the highest value for `Losprout/Greer' population. Crosses among Brevor, Clark's Cream, and Losprout suggested that Brevor differs from Losprout and Clark's Cream for genes controlling dormancy, whereas Clark's Cream and Losprout may have genes in common.

New white winter club cultivar.

A new, bearded, semidwarf club `WA7752' (ARS9412) was approved for release in 1997. WA7752 has moderate resistance to strawbreaker foot rot, medium tolerance to Cephalosporium stripe, resistance to leaf rust, stripe rust, and powdery mildew. WA7752 has club wheat flour quality significantly better than that of Hyak and Rohde, being similar to that of Tres and Rely, but generally lower than that of Paha. WA7752 has Glu1 subunits of null (1A), 6 (1B), and 2 + 12 (1D). These subunits generally are considered to be most favorable for club wheat. Yield potential has exceeded or equaled other high-yielding, semidwarf, club varieties in ARS, WSU, and regional tests. WA7752 is being released mainly as a foot rot resistant replacement for Hyak, which has atypical club wheat flour quality. To date, WA7752 has graded consistently as club wheat by federal (FGIS) inspectors. Inconsistent classification as club wheat has become a problem with some recently released club wheat varieties.

Publications.

Jones SS, Murray TD, and Allan RE. 1995. Use of alien genes for the development of disease resistance in wheat. Ann Rev Phytopath 3:429-443.

Peterson Jr. CJ, Allan RE, Morris CF, Miller BC, Moser DF, and Line RF. 1995. Registration of `Rod' wheat. Crop Sci 35:594.