Blissworth, Northampton, UK.

Paul Wilson and Graham Urquhart.

The 1995-96 season. Drilling conditions in autumn 1995 were good, following rains that assisted seed bed preparation. Yield trials and nurseries were planted into fine, moist soils over a wide range of soil types. The winter was cold, with prolonged spells of easterly winds. However, no winterkill or damage was scored at any of the yield or nursery locations. After a late spring, the weather warmed up, and plants at all sites grew well. The summer was warm and dry with many areas in eastern England experiencing drought conditions causing trials to be abandoned (including the NIAB trials site at Cambridge). Pioneer's yield trials and nurseries, being located further west, did not suffer from drought conditions to the same extent. Yield trials and breeding nurseries were harvested in good condition before the rain arrived towards the end of August.

Breeding nursery. Prior to 1996, all the plant breeding for Pioneer's U.K. entries was grown at Pioneer's wheat station at Frouville, France, because of limited resources in the U.K. For the 1996 season, all generations from F₃ onwards were moved to the Northampton site. Good results were obtained using spreader beds for yellow rust infection enabling excellent selection for resistance to this disease. Natural infection by powdery mildew also was excellent in the breeding nursery.

Natural infection by yellow rust at all yield trial sites was very low, whereas natural infection by powdery mildew was high at all but the southern yield site. Septoria tritici infection was greatest at the southern yield site (Andover, Hants.), with the worst of the check varieties (Riband) scoring 1-2 (1 = least resistant, 9 = most resistant).

Field automation/machinery. A Husky FS/2 was used to record and upload to a PC a range of traits from heading date to disease scores in the yield trials throughout the season. The machine increased the rate of recording over using a field book and pencil and increased the level of objectivity. However, field books also were used for taking more general notes on pedigrees and trial conditions. Technology has not completely replaced the pencil and paper.

The Husky also was used as part of an automated weighing and moisture system mounted on a Hege 140 combine. The system is designed for near-continuous harvesting with stop time only for normal combine clean out. High harvest rates of plots per hour were achieved with the new system after the inevitable teething problems. The great advantage is that yield and moisture data are ready to upload to the PC as soon as the combine leaves the field. A printer is included with the system, providing hard copy backup should problems arise. Two new Hege drills were purchased for planting in autumn 1996, a Hege 80 for yield plots and a Hege 90 for ear rows (with telemetric metering). After setup, both drills performed very well. Minor adjustments will be required for depth of drilling control for planting in 1997.

TRIGEN SEED SERVICES LLC

8024 Telegraph Road, Bloomington, MN 55438, USA.

Robert W. Romig and Daniel R. Romig, Bloomington, MN and Hector Lerner, Buenos Aires, Argentina.

Our wheat program completed 4 years of activity in May, 1997. We now have U.S. nursery sites near San Antonio, TX; Garden City, KS; Shakopee, MN; and Yuma, AZ. Additionally, we have a spring wheat trial in California near Fresno and should again have a spring wheat trial in the Columbia Basin in Washington in 1997. We have established our Argentine nursery site near the town of Diego Gaynor, about 100 km northwest of Buenos Aires. We are now registered as a `Criadero' in Argentina, so that data from our replicated trials can be submitted for varietal registration purposes. Crossing blocks are grown in Chile, as in the past.

The 1995-96 season was a mixed affair. Our winter wheat increases in the high plains of Texas were blown out of the ground by a combination of drought and high winds, causing a set-back of about 2 years in our winter wheat timetable. The severe drought also stressed our early-planted dryland nursery and trials in south Texas, which were subsequently grazed to the ground by deer, in the spring shortly after heading. We grew our 1996 spring wheat nursery under irrigation in Texas with excellent results.

The discovery of Karnal bunt in Arizona in the spring of 1996 led to a quarantine of wheat seed produced there. Fortunately, no spores were detected in grain harvested at our Yuma nursery, which meant that we could ship and plant this seed after following the APHIS-developed treatment protocol. However, the inspection process and treatment delayed shipment of seed nearly a month.

Consequently, we could not return seed from head rows of long-cycle wheats from Argentina for timely planting there. We grew these instead in south Texas in the 1996-97 season, so as not to lose time advancing these materials. Seed of the best of these lines will be returned to Argentina for trialing in 1997. We did return seed of Argentine short-cycle selections for a normal planting date. Plant development of these selections in 1996 was excellent. Many of the proprietary of our experimental lines seem promising.

Planting of the 1996 spring wheat nursery and trials in Minnesota was delayed nearly 1 month. The late planting favored leaf and stem rust development, which led to an effective selection for rust resistance. Results from our preliminary trial of spring wheat suggest that some of our lines may be well-adapted in both countries, that is selections from certain crosses seem well adapted in both hemispheres. We are trying to assess the reciprocal competitiveness of these varieties.

Many Argentine varieties have shown promise in our U.S. trials. Most of these are short-cycle varieties, but several long-cycle varieties also have shown good adaptation in south Texas. Future evaluation of these latter wheats will be aimed at evaluating their winter hardiness. We currently have small increases of 15 candidates of Argentine origin.

Our first marketing venture deals with the introduction in 1997 in south Texas of the Minnesota-developed spring wheat Norm. Trial results show that Norm outperforms Wheaton, the most widely grown spring wheat in the area. We have structured a licensing agreement with the Minnesota Agricultural Experiment Station, because Norm is a `PVP' variety that can be sold only as a class of certified seed.

ITEMS FROM ARGENTINA

ARGENTINEAN COOPERATIVES ASSOCIATION LTD.

Estomba 458, 8000 Bahia Blanca, Bs. As., Argentina.
Ruben Miranda and A.C.A. Criadero.

The area near the influence of the ACA Wheat Breeding project is about 2.5 million hectares. Wheat suffered a severe drought during the entire 1996 season. Frosts damaged the plants during tillering, and high temperatures caused flowering to be between 7-12 days earlier than normal. The grain-filling period was hot and short, and it probably caused low levels of absicic acid production. Prolonged rains before harvest produced sprouting in a major portion of the crop. It is estimated that at least one million tons must be sold as feed wheat.

Cooperacion Nahuel(NANIHUE/NS879.4) is being released. Cooperacion Nahuel is a hard red facultative-type wheat, proven in our own yield trials (Cabildo, Bs. As., Argentina). In a 3-year average, it yielded 5 % more than the three checks. Nahuel is adapted to semiarid and semihumid areas and has a good resistance to local races of leaf and stem rust.

CENTRO DE ESTUDIOS FOTOSINTITICOS Y BIOQUEMICOS-CEFOBI

Center for the Study of Photosynthesis and Biochemistry, Consejo Nacional Investigaciones Cientaficas y Tocnicas, Universidad Nacional de Rosario, Fundacion Miguel Lillo, Suipacha 531, 2000 Rosario, Argentina.

G.D. Cervigni, S. Bacigaluppo, M.I. Reggiardo, H.R. Permingeat, and H.Vallejos.

Second release of transgenic wheat with herbicide resistance obtained in Argentina.

CEFOBI is one of the first academic labs in the world to obtain the genetic transformation of bread wheat. CEFOBI has been working on this project for the past 6 years, concentrating its efforts on the genetic engineering of Argentinean cultivars (spring wheat). In 1995 and 1996, two field trials of transgenic wheat were made under supervision of The National Advisory Commission for AgBiotech (CONABIA). These assays, and another two in maize, were the first transgenic cereals made and developed in Argentina.

These field trials correspond to several transformation events obtained with the commercial cultivar Buck Omba a short-cycle bread wheat. A gene conferring resistance to ammonium glufosinate, the active molecule of the herbicide, was introduced into Buck Omba using a home-made microparticle accelerator and a short and efficient selection protocol developed in our lab.

The trials included the analysis of advanced families (R₄) showing the stability of the transgene through numerous meiotic events among four generations of transgenic wheat. The expression of the foreign gene was evaluated by topic application of a Basta solution in the leaves. The levels of resistance observed in the field correlated with those reported in the greenhouse for early generations. The resistance levels were correlated and confirmed by molecular analyses, such as PCR, dot and Southern blots, and PAT activity, which detected the presence of the bar gene. A Mendelian segregation of the transgene was observed in most of the families assayed.

Las Cabanas y Los Reseros son, (1712) Villa Udaondo, Castelar, Buenos Aires, Argentina.

Glutenin composition and presence of the T1BL-1RS translocation in Latin American advanced lines.

L.A. Pfloeger and E.Y. Suarez.

Research was conducted to evaluate the storage protein composition of South American wheat germplasm. Three hundred lines of the LACOS Program, consisting of high-yielding and disease-resistant advanced lines from six South American countries (Argentina, Brazil, Chile, Paraguay, Bolivia, and Uruguay), were chosen as source material. Their HMW-glutenin subunit composition and the presence of the T1BL-1RS wheat-rye translocation were investigated.

Protein analyses were made under the supervision of Prof. D. Lafiandra in the Agrobiology and Agrochemistry Department, Tuscia University, Viterbo, Italy. The HMW-glutenin subunit composition as revealed by SDS-PAGE allowed the material to be scored for quality (Payne 1987).

Many CIMMYT and South American varieties have the T1B-1RS translocation chromosome, which is known to produce sticky dough and poor quality flour. The presence of this wheat-rye translocation was studied in A-PAGE (aluminum lactate buffer). The rye-adjusted Glu1-quality score (Payne et al. 1987) was calculated in order to have a better estimation of breadmaking quality.

Among the 300 lines studied, 46 were heterogeneous (segregating lines) for HMW-glutenin subunits. Six lines from Chile were T. durum lines and were not included in the analysis.

The unadjusted Glu1 score of the LACOS advanced lines were high for all the countries (Table 1). The main reason for the high quality scores was the low frequency of the null form of GluA1, which is considered to produce low strength in wheat compared with its alternative forms. The high frequency of subunits 5+10 at the GluD1 locus was another factor contributing to high quality scores. Argentine lines have the highest score (9.36), and Paraguay the lowest (8.16). However, taking into account that the percentage of the T1B-1RS translocation was high in all the countries, varying from 34.54 % for Chilean lines, to 78.57 % in lines from Paraguay. The detrimental effects on breadmaking quality of this translocation and the ineffectiveness against certain rust strains should be considered to exclude T1B-1RS in the breeding material.

Table 1. Percentage of T1B-1RS wheat-rye translocation and mean Glu1 score among advanced lines from different countries of South America.

Further analysis on breadmaking quality of selected advanced lines already in progress will establish the relationships between allelic composition for storage proteins and breadmaking quality in the Latin American wheat germplasm.

References.

Payne PI. 1987. Genetics of wheat storage proteins and the effect of allelic variation on bread making quality. Ann Rev Plant Physiol 38:141-153.

Payne PI, Nightingale MA, Krattiger AF, and Holt LM. 1987. The relationships between HMW glutenin subunit composition and the bread making quality of British-grown wheat varieties. J Food Agric 40:51-65.

Argentinean wheat germplasm characterization by the Ibf-1 isozyme system.

E. Suarez and G. Tranquilli.

In order to look for diagnostic markers, 106 Argentinean varieties of wheat from different breeders and from different release times (1930 to 1995) were characterized using the Ibf-1 (Iodine binding factor) system (Liu and Gale 1989). About 13 different patterns were detected in common within the analyzed varieties (Fig. 1). Only a few of those cultivars showed unique patterns (see Table 2).

In this analysis, 11 native lines derived from an aboriginal germplasm also were included. Despite their phenotypic variation for grain and coleoptile color, plant height, ear-emergence time, glume pilosity, awns, and yield, the lines tended to be uniform for Ibf-1 pattern (see pattern M, Fig. 1).

The substitution lines of Sinvalocho MA (an Argentinean variety) into Chinese Spring also were evaluated. Some polymorphism was found between Chinese Spring and Sinvalocho MA patterns, which could be explained just only partially by Chinese Spring/Sinvalocho MA 5A substitution line. The remaining variation was not accounted for by any other single chromosome.

Reference.

Liu CJ and Gale MD. 1989. Theor Appl Genet 77:233-240.

Table 2. Classification of Argentinean wheat cultivars based on Ibf-1 pattern (Ibf-1 patterns according to Fig. 1 above).

Publications.

Tranquilli G, Suarez E, Saione H, Sacco F, and Tozzini A. 1996. Effect of host allelic dosages on Triticum aestivum-Puccinia recondita specific interaction. Plant Breed 115.

Franzone F, Suarez E, Solari R, Favret E, Rios R, and Diaz-Paleo D. 1996. Genetic stability after "in vitro" culture of 3 wheat varieties currently showing different karyotyic instability. Plant Breed 115:89-93.

Bullrich L, Tranquilli G, Pfluger L, Suarez E, Barneix A, and Dubcovsky J. 1996. Bread making quality and yield performance of 1BL/1RS Argentinean germplasm. Proc 6th International Gluten Workshop. Australia.

BIOTECHNOLOGY INSTITUTE - CICV - INTA

CC 77, 1708 Moron, Castelar, Argentina.

Characterization of 110 Argentine wheat varieties using SSR markers.

A.R. Schlatter, M.M. Manifesto, M. Echaide, H.E. Hopp, and J. Dubcovsky (Department of Range Science, University of California, Davis).

One hundred ten wheat varieties were screened for polymorphisms in SSRs representing four different loci; two storage protein loci (Glu-A3 coding for LMW glutenins, located on the short arm of chromosome 1A, and Gli-B1 coding for gliadins, located on the short arm of chromosome 1B) and two unrelated loci (WMS-46 on the short arm of chromosome 7B and xconll-5 on chromosome 1A). The number of alleles detected was 39, ranging from 5-13 per locus with a mean of nine alleles per locus. All of the alleles behaved as codominant markers and, in contrast to RFLP markers, distinguished between homeoloci. The polymorphism information content (PIC) calculated showed the following values: PIC (Glu-A3) = 0.82, PIC (Gli-B1) = 0.88, PIC (WMS-46) = 0.70, and PIC (xcnll-5) = 0.40. These values are much higher than RFLP PIC values, which had a mean value of 0.41 for the Glu1-1A, Glu1-1B, and Glu1-1D RFLP markers. These high PIC values allow a fine characterization of the genetic variability present in the germplasm bank, complementing storage protein electrophoretic patterns and RFLP data.

GENETICS INSTITUTE - INTA

University of Buenos Aires, Cathedra of Crop Health and Statistics, CC 25 (1712) Castelar, Argentina.

Awnedness in a F₂ population of the bread wheat cross `Buck Charraa/Thatcher'.

B.A. Perez and M. Zanelli.

The awns in bread wheat have been associated with increased grain yield. The genotype aa b₁b₁ b₂b₂ hdhd has been associated to awned plants, whereas B₁B₁ B₂B₂ hdhd has been related to awnless plants. Breeders have been selecting for this trait for many years, but little is known about the genetics of awnedness in the Argentine bread wheat cultivars. Buck Charraa (Pedigree: Rafaela MAG-Buck Pampero/Buck Relen//Klein Impacto/Rafaela MAG-Buck Pampero/3/Lovrin/4/Rafaela MAG-Buck Pampero/Buck Relen//Klein Impacto/Rafaela MAG-Buck Pampero) is a fully-awned, Argentine bread wheat cultivar developed by Criadero Jose Buck S.A. in 1989. Thatcher is a Canadian cultivar that is not fully awned. An F₂ population of 592 plants from the cross `Buck Charraa/Thatcher' was classified according to awn type with 167 out of 592 fully-awned plants. The F₁ data and X² analysis of F₂ data indicate a recessive gene is associated with the fully-awned trait in Buck Charraa (X² = 3.25, P > 0.05).

Seedling reaction to powdery mildew, Blumeria graminis f. sp. tritici, in bread wheat cultivars.

C. Garaa Sampedro ¹, B.A. Perez, V. Lopez ³, and E. Wright ¹.

¹ University of Buenos Aires, Faculty of Agronomy Cathedra of Crop Health; and Cathedra of Statistics³.

Five Argentine bread wheat cultivars (Buck Charraa, Cruz Alta Inta, Klein Orion, Norkin Lider, and ProInta Federal) were evaluated for seedling reaction to an Argentine isolate of powdery mildew avirulent on Ulka 1 (Pm2), Asosan (Pm3a), Chul (Pm3b), and Khapli (Pm4a), and virulent on Norka (Pm1). There were significant differences among the tested cultivars. The cultivar Buck Charraa was highly resistant and may have been derived from the winter cultivar Lovrin. Cruz Alta Inta and Klein Orion were slow-mildewing. Cruz Alta Inta probably derived resistance from Kavkaz (Pm8), which has the rye T1B-1R translocation.

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