Cycle III Report

Javier Hernandez, Tanya Filichkin, Scott Fisk, Laura Helgerson, and Patrick HayesBarley Project. Oregon State University. Corvallis, Oregon, USA.

Germplasm:The Cycle III doubled haploid panel is a germplasm array of 373 doubled haploid lines derived from crosses among 10 parents with resistance to one or more rust diseases (stem, stripe, leaf) and 3 checks. This trial was grown in a total of three environments over the 2018/19 and 2019/20 seasons. This report covers stripe rust and scald data generated across all environments.

Stripe rust (and other diseases) - assessment procedures:Disease susceptibility was measured for the principal diseases using severity and/or infection type present at Corvallis, OR and Davis, CA. Severity (Sev) was scored as percentage of leaf area affected with the disease on a plot basis, whereas infection type (IT) was recorded according the scale proposed by McNeal et al. (1971). Rust nurseries were evaluated for adult plant resistance to barley stripe rust (BSR, incited by Puccinia striiformis f. sp. hordei) using infection type and severity at Davis, CA and severity at Corvallis, OR. A Randomized Complete Block Design with two replications and three checks - DH130910 (released as Lightning), Thoroughbred and Robust - was used. Natural infection was supplemented with artificial inoculation. Notes on other diseases were recorded as they were present in this trial. In this data set, we also provide information on scald (SC, incited by Rhynchosporium commune). Scald was evaluated using severity at Corvallis during 2019 and 2020 seasons.

Data: Please see request invitation to Box folder from Patrick.m.hayes@oregonstate.edu

Publication(s): In preparation

Funding: Support provided by USDA-ARS-NACAs for stripe rust and stem rust research.

This report: In this report, we provide data and analyses on stripe rust and scald resistance in the Cycle III population.

Cycle III 2019 – Oregon data

Reaction to BSR and SC at adult plant stage; Corvallis, OR

Histogram distribution across dates and diseases

2019 Field Evaluations

The barley stripe rust nursery was evaluated using severity as the percentage of leaf area affected with stripe rust on a plot basis. At Corvallis, disease notes were taken two times during the growing season, at a 10 day interval.

For this year, only data from Corvallis was generated for Cycle III. At this location, a large range of phenotypic variation among entries was observed. Robust, Lightning (DH130910), and Thoroughbred were used as checks. All checks exhibited a range of severity values as expected.

Robust and Thoroughbred showed the highest severity values with 59% and 66%, respectively. The resistant check Lightning had the lowest value: 10%. A total of 152 lines had disease severities < 15% and 99 lines were rated with severity values > 40%. 50% of the entries in the panel exhibited severity values between 9-40%.

Scald was evaluated during this season. The Cycle III trial exhibited variation for SC with 50% of lines exhibiting severity values ranging from 1.5 to 17.5%. The Lightning and Thoroughbred checks had low severities: 1 and 2%, respectively. The Robust check was susceptible, with a severity of 28%.

Analysis of variance for BSR and SC

BSR OR19Severity Date 1 Df Sum Sq Mean Sq F value Pr(>F) Line 373 196657 527.2 6.314 < 2e-16 ***Rep 1 600 600.1 7.188 0.00767 ** Residuals 373 31144 83.5 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1Severity Date 2 Df Sum Sq Mean Sq F value Pr(>F) Line 373 335900 900.5 8.108 <2e-16 ***Rep 1 229 229.1 2.063 0.152 Residuals 373 41428 111.1 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

SC OR19Severity Date 1 Df Sum Sq Mean Sq F value Pr(>F) Line 373 90739 243.3 2.001 1.68e-11 ***Rep 1 2976 2976.0 24.483 1.14e-06 ***Residuals 373 45340 121.6 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1Severity Date 2 Df Sum Sq Mean Sq F value Pr(>F) Line 373 202681 543 1.885 6.46e-10 ***Rep 1 9261 9261 32.131 2.89e-08 ***Residuals 373 107513 288 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Correlation among dates for BSR and SC

LSD test for dates and diseases

Please see LSD test Cycle III at https://barleyworld.org/barley-stripe-rust-bsr

Cycle III 2020 – Oregon and California data

Reaction to BSR and SC at adult plant stage; Corvallis, OR and Davis, CA

Histogram distribution across dates and sites

2020 Field Evaluations

Barley stripe rust nurseries were evaluated using severity and infection type at Davis and severity at Corvallis. At Davis, disease notes were taken two times during the growing season at a 10 day interval. At Corvallis, one evaluation was performed once flowering was finished.

Corvallis and Davis had similar levels of disease. At both locations, Lightning, Thoroughbred, and Robust were used as checks and exhibited a range of severity values as expected.

At Corvallis, Robust and Thoroughbred showed the highest severity values with 60% and 85%, respectively. The resistant check Lightning had the lowest value with 4%. A total of 195 lines showed 10% or less disease severity whereas 67 lines had severity values > 40%. 50% of the lines at this location exhibited severity values between 2% and 30%.

At Davis, a range of phenotypic variation was observed among lines and across dates. Controls Robust and Thoroughbred showed the highest infection type/severity values both with 9/85%. The resistant check Lightning had the lowest value with 4.5/20%.

Infection type: A total of 150 lines had infection types < 3 whereas 56 lines were rated with infection type > 7, similar to the susceptible checks. 50% of the lines at this location had infection type values between 1.5 and 6.

Severity: 50% of the lines in this trial exhibited severity values between 3 and 40%. As observed in the histogram, 187 lines had severities < 10% and 106 lines exhibited severities > 40%.

Scald (SC) was evaluated at Corvallis during this season at heading. The Cycle III population exhibited variation for this trait with 50% of lines having severity values ranging from 0 to 15%. The Robust check was susceptible, with a severity of 55% whereas Lightning and Thoroughbred had severities of 4% and 2%, respectively.

Analysis of variance for BSR and SC

BSR OR20Severity Date 1 Df Sum Sq Mean Sq F value Pr(>F) Line 382 317405 831 5.87 < 2e-16 ***Rep 1 6751 6751 47.69 2.09e-11 ***Residuals 382 54073 142 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

SC OR20Severity Date 1 Df Sum Sq Mean Sq F value Pr(>F) Line 382 215560 564.3 3.019 <2e-16 ***Rep 1 45 44.7 0.239 0.625 Residuals 382 71394 186.9 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

BSR CA20Infection Type 1 Df Sum Sq Mean Sq F value Pr(>F) Line 382 3040.0 7.958 3.149 <2e-16 ***Rep 1 0.6 0.632 0.250 0.617 Residuals 382 965.4 2.527 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1Infection Type 2 Df Sum Sq Mean Sq F value Pr(>F) Line 382 5313 13.908 6.927 < 2e-16 ***Rep 1 27 27.070 13.484 0.000275 ***Residuals 382 767 2.008 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1Severity Date 1 Df Sum Sq Mean Sq F value Pr(>F) Line 382 127077 332.7 2.694 <2e-16 ***Rep 1 197 196.5 1.592 0.208 Residuals 382 47162 123.5 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1Severity Date 2 Df Sum Sq Mean Sq F value Pr(>F) Line 382 392040 1026 6.186 <2e-16 ***Rep 1 4277 4277 25.778 6e-07 ***Residuals 382 63379 166 ---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Correlation among dates for BSR and SC

LSD test for dates and diseases

Please see LSD test Cycle III at https://barleyworld.org/barley-stripe-rust-bsr

BLUPs across environments (OR19, OR20, and CA20) for BSR

The best linear unbiased predictions (BLUPs) for each line across three environments - Corvallis 2019, Corvallis 2020 and Davis 2020 - for disease severity at adult plant stage, expressed as percentage (%) of leaf area affected with barley stripe rust were obtained and plotted in a histogram distribution graphic. A range of phenotypic variation was observed among lines when all environments were included in the same model. The susceptible checks Robust and Thoroughbred showed the highest severities with 64% and 75%, respectively. The resistant check Lightning has the lowest severity, at 12%. A total of 161 lines exhibited values ≤ 15% whereas 50 lines were rated with severity ≥ 40%. The heritability of adult plant resistance was 0.57.

Histogram BLUPs

H 2=0.57