Red smudge of durum wheat and its effect on germination, seedling emergence, and plant growth.

M.R. Fernandez, J.C. Clarke, and R.M. DePauw.

The effect of red smudge infection on the performance of four durum wheat cultivars was examined under controlled-environment and field conditions. The rate of seed germination was not affected, whereas the percent germination of naturally infected seeds was lower in the red smudge treatment than in the control (healthy). Lengths of the coleoptile and seminal roots at 12 days were also lower in the red smudge treatments. The percent and rate of emergence of seedlings also were affected negatively by the red smudge treatment under both field and controlled-environment conditions. Time to heading was lower for the diseased than for the healthy treatments, but total number of spikes, aboveground plant dry weight, and grain yield per plant were similar among treatments. However, in the field, the lower emergence of plants derived from red-smudged seed resulted in poorer plant stands and reduced grain yield per unit area.

In conclusion, red smudge infection of durum wheat seed was found to affect seed quality and seedling vigour. The reduction in percent emergence and rate of emergence of seedlings, and slower development of plants derived from naturally infected red-smudged seeds could not be attributed to any differences in the rate of seed germination, but seemed to be related to the lower vigour of the developing seedlings and lower percent germination.

Black point and red smudge in durum and common wheat cultivars in southern Saskatchewan in 1994.

M.R. Fernandez, J.M. Clarke, R.M. DePauw, and R.B. Irvine.

The incidence of black point and red smudge was examined in 13 commonly grown durum and common wheat cultivars, under irrigated conditions, at Swift Current and Outlook, in southern Saskatchewan. For all cultivars, levels of black point at Swift Current (average of 3.0 %) were lower than in the wet years of 1992 and 1993 (10.4 and 22.9 %), but similar to those found in the drier years of 1990 and 1991 (3.4 and 6.7 %). Black point incidence at Outlook (9.7 %) was higher than in 1991 (6.4 %) and lower than in 1990 or 1992 (17.4 and 30.6 %) (no data from 1993).

At both locations, the lowest average levels of black point were found in the hard red spring cultivars (< 2.0 %). At Outlook, the highest average black point incidence was observed in the durum wheat (13.1 %) and the soft white spring wheat cultivars (15.8 %).

The incidence of red smudge was similar at both locations for all 13 cultivars combined (0.4-0.8 %). These levels were lower than in 1992 or 1993 (1.5 and 5.9 %), but similar to those of 1990 and 1991 (0.1 and 0.4 %). At Swift Current, red smudge was highest for the soft white spring wheats (0.8 %) and, at Outlook, it was lowest for the hard red spring wheats (0.2%).

New cultivars.

R. M. DePauw, T.N. McCaig, R.E. Knox, J.M. Clarke, J.G. McLeod, and M.R. Fernandez.

AC Barrie (BW661), hard red spring, exhibits both higher grain yield and grain protein content, improved milling and baking properties, stronger straw, and improved disease resistance compared to the best checks. It yields similar to the high yielding cultivar Laura and has the advantage of not requiring a seed treatment to control common bunt.

AC Karma (HY395), Canada Prairie spring (white), is the first cultivar in this class to have genetic resistance to prevalent races of both common bunt and loose smut. In addition, it has improved milling and end-use quality, improved resistance to leaf and stem rust, improved straw strength, and reduced time to maturity compared to Genesis, which is the only cultivar in this new class.

AC Alta, a spring triticale, has improved grain yield potential, seed size, and lodging resistance compared to currently registered spring triticales for western Canada.

AC Rifle is the first semidwarf rye cultivar registered in Canada. AC Rifle is about 30 % shorter than the conventional taller cultivars. It represents a significant improvement in lodging and shattering resistance. It is also amenable to direct harvesting. Adoption of this cultivar by producers will greatly enhance the harvestability of the crop, resulting in a competitive advantage in production. AC Rifle was awarded to Proven Seed-UGG by competitive tender. A manuscript describing AC Rifle has been prepared and will be submitted to CJPS in the near future.

T128 triticale was supported for registration in February. This high yielding cultivar has superior resistance to harvest-time sprouting and greater test weight compared to all other triticale cultivars registered for production in Canada. Potential for commercialization is high and should be achievable by 1997 or 1998, likely be a codevelopment partner.

Publications.

Bernier A, Howes N, Kim H, Kim W, and Knox R. 1994. Loose smut resistance in Chinese Spring wheat. Canadian Phytopathological Society, Edmonton, Alberta. Can J Plant Path (Abstract, in press).

Clarke FR, Baker RJ, and DePauw RM. 1994. Moving mean and least squares smoothing for analysis of grain yield data. Crop Sci 34:(In press).

Clarke JM, DePauw RM, McLeod JG, and McCaig TN. 1994. Variation for preharvest sprouting in durum wheat. Crop Sci 34:1632-1635.

Clarke JM, Howes NK, McLeod JG, and DePauw RM. 1993. Selection for gluten strength in three durum wheat crosses. Crop Sci 33:956-958.

Clarke JM, McCaig TN, and DePauw RM. 1993. Relationship of glaucousness and epicuticular wax quantity of wheat. Can J Plant Sci 73:961-967.

Clarke JM, McCaig TN, and DePauw RM. 1994. Inheritance of glaucousness and epicuticular wax in durum wheat. Crop Sci 34:327-330.

Clarke JM, McCaig TN, Vallega V, DePauw RM, McLeod JG, and Thiessen LL. 1995. Registration of durum wheat genetic stocks near-isogenic for glaucousness. Crop Sci 35:(In press).

DePauw RM, McLeod JG, Clarke JM, McCaig TN, Fernandez MR, and Knox RE. 1994. AC Eatonia hard red spring wheat. Can J Plant Sci 74:821-823.

DePauw RM. 1994. International Germplasm Exchange and Wheat Breeding in Canada. Can Soc Agron, Regina, Sask. 12 July, 1994. Can J Plant Sci (In press).

Fenn D, Lukow OM, Bushuk W, and DePauw RM. 1994. Milling and baking quality of 1BL/1RS translocation wheats. II. Influence of cultivar and dough stickiness. Cereal Chem (In press).

Fernandez MR, Clarke JM, and DePauw RM. 1994. Response of durum wheat kernels and leaves at different growth stages to Pyrenophora tritici repentis. Plant Dis 78:597-600.

Fernandez MR, Clarke JM, DePauw RM, Irvine RB, and Knox RE. 1994. Black point and pink smudge in irrigated durum wheat in southern Saskatchewan. Can J Plant Pathol (In press).

Fernandez MR, Clarke JM, and DePauw RM. 1994. Effect of red smudge infection of durum wheat on seed quality. Can J Plant Path (Abstract, in press).

Jalil A, Selles F, and Clarke JM. 1994. Effect of cadmium on growth and the uptake of cadmium and other elements by durum wheat. J Plant Nutr 17(11):1839-1858.

Jalil A, Selles F, and Clarke JM. 1994. Growth and cadmium accumulation in two durum wheat cultivars. Comm Soil Sci Plant Anal 25:2597-2611.

Knox RE. 1994. Localization and linkage analysis of a loose smut resistance gene on chromosome 6A of wheat. IX. Biennial Workshop on the Smut Fungi, CIMMYT, Mexico. (Abstract, in press).

McCaig TN and Clarke JM. 1995. Breeding durum wheat in western Canada: Historical trends in yield and related variables. Can J Plant Sci 75:(In press).

McLeod JG, Townley-Smith TF, DePauw RM, and Clarke JM. 1994. AC Copia Spring Triticale. Can J Plant Sci 74:(In Press).

ITEMS FROM THE PEOPLES REPUBLIC OF CHINA

Wheat Institute, Henan Academy of Agricultural Sciences

450002, Zhengzhou, Henan, China.

Zuoji Lin, Shenghui Jie, and Qingru Lai.

1993-1994 season.

A dry sowing season followed by a cold winter caused less tillering and vegetative growth. Spring rainfall was sufficient. However, high temperatures and a dry climate during the grain filling period resulted in lower kernel weight. The total yield was less than that of the previous season.

Quality requirement for a sponge cake and soft biscuit.

The quality characteristics of 49 wheat and flour samples have been examined for their suitability for sponge cake and soft biscuit manufacturing. The results indicated that sedimentation value was a valuable index. Samples that possessed less than a 20 ml sedimentation value showed better results for both cake and biscuit. However, the wet gluten content of those samples varied from 18 % to 28 %, possibly due to the strength of the flour dough. The farinogram criteria for the better samples were water absorption less than 58 % and development time less than 2 minutes. The preliminary results also showed that sponge cakes usually required less gluten content(less than 24 %), but a slightly longer stability time was permitted (3 min.). It was interesting to note that the sample with least gluten content (17 %) did not show better performance for biscuit, and the gluten content and dough strength were complemented.

Recurrent selection.

Two lines have been selected from a recurrent selection population for powdery mildew resistance. These lines showed not only high resistance to powdery mildew, but also possessed high yield potential and good quality for biscuit manufacturing. It was suggested that improvement for both agronomic and quality characteristics could be carried out in a recurrent selection population using male sterile gene, Ms2.

Wheat Breeding Institute

Nanjing Agricultural University, Nanjing, 210095, China.

Guo-Liang Jiang, Zhao-Su Wu, Shi-Rong Yu, Xi-Zhong Wei, You-Jia Shen, Yong Xu, Zhao-Xia Chen, Ji-Min Wu, and Shi-Jia Liu.

Recurrent selection and its breeding progress for resistance to scab in wheat utilizing the dominant male-sterile gene Ta1(Ms2).

Scab, caused by Gibberella zeae in wheat, is one of the most severe diseases in China, and breeding for resistance is of special significance in the mid-lower Yangtze Valley and the South China winter wheat regions. Gene pools with improved scab resistance were developed through multiple-parent crossing and recurrent selection using the dominant male-sterile gene, Ta1(Ms2). For each of five populations, phenotypic recurrent selection was separately conducted for 4-5 cycles and the selection responses were studied. The establishment of a base population, selection method and intensity, selection environment, character correlation, and multiple-trait selection were analyzed and discussed. Combined with the practice of developing scab-resistant and high-yielding cultivars or germplasm, a series of experiments was conducted in order to prove the efficiency of recurrent selection using the gene Ta1 in genetic improvement of scab resistance in wheat. The main results and conclusions were as follows:

(1) The mean resistance of a population to scab and the frequency of resistant genes and plants were increased significantly under phenotypic recurrent selection. We demonstrated that recurrent selection, utilizing the dominant male-sterile gene Ta1, is effective in the improvement of wheat for scab resistance. With RP from C₁ to C₅, GPI from C₀-C₄, and GPII from C₀-C₄, the selection gains for resistance were 8.6 %, 7.5 %, and 6.2 % per cycle, respectively.

(2) For RP and GPI, the genetic variance for diseased spikelets within the populations of the gene pools was reduced under selection, but the coefficient of variation was not. No significant change in genetic variability was found for the other populations. The genetic variability was well maintained for agronomic traits. Further selection for either resistance or agronomic traits would still be effective.

(3) For the establishment of a base population, the methods with GPI and GPII were more simple and easy and had greater effect. Unfavorable influences of undesired genes on recurrent selection could be reduced through individual plant selection and combination discarding. Phenotypic mass-plant selection was more advantageous compared with phenotypic mass-spike selection for both scab resistance and comprehensive agronomic performance. The comprehensive performance of a population could be improved through multiple-trait selection.

(4) The mean performance of 26 recurrent selection strains was distinctly better than that of the 19 original parents for scab resistance, plant height, biomass, grain yield, harvest index, 1,000-grain weight, kernels per spike, etc. Ten strains from the gene pool attained or exceeded the desired level for scab resistance and seven important agronomic traits. Recurrent selection strain W14, in resistance to scab, and Changjiang 9045 and 9046, in grain yield and plant dwarfism, exceeded all of the original parents. We demonstrated that the development of a gene pool through recurrent selection integrated with conventional breeding methods using the gene Ta1 is entirely effective and feasible, both in incorporating scab resistance with high-yielding capacity to develop new wheat cultivars and germplasm and in accumulating desired favorable genes to produce transgressive genotypes.

Breeding and germplasm research.

A new scab-resistant cultivar, Changjiang 8809, has been accepted in the Regional Experiments of Jiangsu and Anhui Provinces. Changjiang 8802, 9035, 9202, and others, bred at Nanjing Agricultural University's Wheat Breeding Institute, along with the land races Fuling Xuxumai, Zitong Nu'ermai, Langzhong Baidongmai, Yongchuan Baimaizi,

and Suining Tuotuomai and the cultivar Fengchan 3, were identified to be good sprout-tolerant white-grained germplasms. The experiment with scab resistance demonstrated that W14, TFSL037, and Changjiang 8809, 8863, 9306, 9307, and 9311, developed through recurrent selection using the dominant male-sterile gene Ta1(Ms2), possess high resistance to scab. The resistance of W14, 9306, and 9311 surpasses the level of the well-known scab-resistant cultivar, Sumai 3. Some high-yielding advanced lines also have been developed through this breeding approach.

Personnel news and changes.

Dr. Guo-Liang Jiang has been appointed to take the responsibility for wheat breeding and related research at NAU since Prof. Zhao-Su Wu retired in 1993. Prof. Zhao-Su Wu died on June 20, 1994, in Nanjing, at the age of 74.  Mr. Ji-Min Wu left NAU for Oklahoma State University as a Ph.D. student in July, 1994.

Publications.

Jiang G-L, Wu Z-S, and Huang D-C. 1994. Effects of recurrent selection for resistance to scab (Gibberella zeae) in wheat. Euphytica 72:107-113.

Jiang G-L, Wu Z-S, and Chen Z-X. 1994. Breeding new scab-resistant wheat germplasm Changjiang 8809. Proc 3rd Nat Youth Symp Crop Genet Breed. China Agricultural Scientech Press, Beijing. Pp. 325-329.

Jiang G-L, Chen Z-X, and Wu Z-S. 1993, Studies on the development of scab-resistant gene pool in wheat. IV. Comparison of scab resistance and plant height between recurrent selection strains and original parents. Proc 1st Nat Youth Acad Symp Wheat Genet Breed. China Agricultural Scientech Press, Beijing. (In press).

Jiang G-L. 1993. Combining recurrent selection with shuttle breeding in wheat using the dominant male-sterile gene Ta1: A proposal for wheat breeding strategy in Yangtze Valley. Proc 1st Nat Youth Acad Symp Wheat Genet Breed. China Agricultural Scientech Press, Beijing. (In press).

Chen Z-X, Jiang G-L, Wang S-P, and Wu Z-S. 1994. Preliminary studies on preharvest sprouting resistance and testing methods in wheat cultivars. Proc 3rd Nat Youth Acad Symp Crop Genet Breed. China Agricultural Scientech Press, Beijing. Pp. 330-333.

Wu J-M, Liu S-J, Wei X-Z, and Xu Y. 1994. A preliminary report on the results of treating wheat grains different in kernel colors with GA₃ and by isoenzymatic analysis with alpha-amylase. J Nanjing Agri Univ 17(3):142-144.

He Z-H, Jiang G-L, et al. eds. 1994. Proc 3rd Nat Youth Symp Crop Genet Breed. China Agricultural Scientech Press, Beijing. (In press).

Liu H-L, Wu Z-S, and Mi J-J eds. 1993. Researches and Advances on Crop Breeding (Vol. 1). Agriculture Press, Beijing.

Liu, H-L, Wu Z-S, and Mi, J-J eds. 1994. Researches and Advances on Crop Breeding (Vol. 2). Southeast University Press, Nanjing.