Development of high yield potential dwarf milling oat varieties in Australia — Dr. Pamela Zwer, Australia

Development of high yield potential dwarf milling oat varieties in Australia

Dr. Pamela Zwer, Australia

ABSTRACT

Pamela Zwer1, Peter McCormack2

1 Oat Breeding Consultant, 7 The Esplanade, Hallett Cove, SA, 5158, E-mail: pkzwer@outlook.com 2 McCormack Enterprises, Lyndoch, SA, 5351

Summary

The creation of OT 207 a semidwarf oat line developed in Canada was a step change for oat breeding in Australia. The first two widely grown semidwarf oat varieties, Echidna, and Dalyup, released in Australia had grain yield increases from 16 to 21 percent compared to the popular tall variety, Mortlock. However, grain quality of the two semidwarf varieties was inferior to Mortlock. Through years of breeding the yield advantage of the semidwarf trait was incorporated in high quality milling varieties for Australia.

Introduction

Dwarfing genes in oat were reported in the literature since 1919 (Brown et al. 1980). The dwarf lines were often too short or had chromosome instability not suitable for use in breeding programs. The oat breeding program at Agriculture Canada in Winnipeg, Manitoba, Canada undertook the development of a semidwarf oat using fast neutrons and gamma radiation treatments (Brown et al. 1980). They selected OT 184 and a line from the fast neutrons treatment was identified and named OT 207. It was determined the semidwarf trait was inherited by a single dominant gene and the line was cytologically stable. OT207 was acquired by the South Australian and Western Australian Oat Breeding Programs. Crosses were made with OT207 in both programs, resulting in the release of Echidna and Dolphin by Dr. Andrew Barr in 1984 for South Australia (SA) and Dalyup by Dr. Robyn McLean in 1988 for Western Australia (WA). Yield potential was significantly higher in these varieties compared to Mortlock, but grain quality was inferior. Utilising recurrent selection in the SA and WA gene pools and developing NIR calibrations for grain quality, the Oat Breeding Program led by Dr. Zwer released high yielding dwarf oat varieties with improved grain quality.

Methods

Varieties and the most advanced breeding lines were entries in randomised complete block Stage 4 yield trials with three replications. The trials were sown at five sites in WA, seven sites in SA, two sites in Victoria (Vic), and four sites in New South Wales (NSW). The grain yield data were analysed for trials from 2000 to 2007 by Statistics for the Australian Grains Industry (SAGI) using multi-environment trial (MET) analysis. Grain quality was assessed using NIR calibrations developed by the SARDI Oat Breeding Program in 1997 and standard physical quality measurements. Quality data presented to contrast Mortlock, Echidna, and Dalyup’s performance was from 2007. Fast forward to 2020 and the data presented is from Stage 4 trials grown from 2015 to 2019. There were five sites in WA, four sites in SA, and one site in NSW. Mortlock was dropped from the entry list because it no longer provided a benchmark for the newer improved varieties. Both grain yield and grain quality were analysed using MET by the Centre for Biometrics and Data Science of Sustainable Primary Industries, the University of Wollongong.

Continued following page....

Results

The oat variety Mortlock was released by the Western Australian Department of Agriculture in 1984. It is considered a tall variety at about 95 cm and became a benchmark for grain quality throughout Australia. It’s parentage is Elan 6161/3/Fulmark/Newton//Swan. The oat variety Echidna was released in 1984 by the South Australian Department of Agriculture. Dr. Andrew Barr incorporated the dwarf gene Dw6 into Australian germplasm by crossing OT207 to West. Echidna is about 65 cm tall, 30 cm shorter than Mortlock. The shorter stature improved lodging and shattering resistance compared to tall oat varieties. Grain yield potential was significantly higher with Echidna producing from 17 to 21% more than Mortlock in WA, SA, Vic, and NSW in 2007. However, physical grain quality was inferior to Mortlock. Screenings were 45% higher and 1000 grain weight was 89% lower than Mortlock in 2007. The oat variety Dalyup was released in 1988 by the Western Australian Department of Agriculture. Dr. Robyn McLean incorporated Dw6 into the WA gene pool in the cross, OT207/Swan//Moregrain/West. Dalyup was 66 cm tall, 29 cm shorter than Mortlock. It’s grain yield was 16 to 18% higher than Mortlock in WA, SA, and NSW in 2007. Screenings were 9% higher and 1000 grain weight 93% lower than Mortlock. Utilising recurrent selection several dwarf and semidwarf oat varieties were released from the SARDI National Oat Breeding Program with high yield potential and enhanced grain quality from 2003. These varieties include Possum, Mitika, Dunnart, Wombat, Bannister, Williams, Kowari, Bilby, and the last variety from the program Koala. NIR calibrations assisted with the selection of varieties with high groat percent which equates to about $100,000 processing savings with each 1% increase. Mitika, Kowari, and Bilby have increased groat percent by 1.8 to 2.3% compared to Echidna. Screenings ranged from 4.1 to 6% in these varieties compared to Echidna at 12%. Grain weight for 1000 kernels was increased from 33.1g in Echidna to 37.5g in Bilby. Increased β-glucan in new variety releases was also a priority.

Conclusion

The creation of the Dw6 mutant and exchange of germplasm was a significant advancement for grain yield potential in Australia. This is a prime example why sharing oat germplasm globally should continue into the future. Yield increases coupled with high milling quality is necessary, so oat can compete with other crops in the farming rotation to ensure consistency of production.

REFERENCES

Brown PD, McKenzie RIH, Mikaelsen K. Agronomic, genetic, and cytologic evaluation of a vigourous new semidwarf oat. Crop Sci 20, 303-306 (1980). Doi: 10.2135/cropsci1980.0011183X002000030003x

Grains Australia thanks – sponsor of theme