Crown rust resistance of oat germplasm from the ARS-

Aberdeen program J. M. Bonman (1), D.E. Obert (1), E. W. Jackson (1), S.A. Harrison (2) and M. L. Carson (3). (1)USDA-ARS, Small Grains and Potato Germplasm Research Unit, 1691 S. 2700 W., Aberdeen ID 83210; (2) Louisiana State University, AgCenter Agronomy Department, 104 MB Sturgis Hall, Baton Rouge, LA 70803; (3) USDA-ARS Cereal Disease Laboratory1551 Lindig Ave., St. Paul, MN 55108.

Where is Aberdeen?

University of Idaho Research and

Extension Center, Aberdeen, ID

Background

• Previously the program targeted the Intermountain West– objective was high yield and quality

• Currently a need to make Aberdeen material more widely useful by incorporating disease resistance

Objectives

Characterize crown rust resistance within Aberdeen cultivars and breeding lines: Field reactions in “hot spot” locations (Castroville,

TX; Baton Rouge, LA) Seedling resistance to many isolates (CDL) Field reactions to single isolates (isolated plots in

Aberdeen, ID) Assess partial resistance of selected materials in

greenhouse inoculations with compatible isolates

Test lines and cultivarsLine/Cultivar Pedigree

89Ab3840 75Ab861 / L75-340294Ab6965 87Ab5597 / 86Ab525995Ab11439 PA8393-1500 / 82Ab24895Ab12847 74Ab2608 / Ajay98Ab7085 86Ab1616 / 89Ab286198Ab7399 Park / 88Ab307399Ab11468 NPB871312-3 / Monida99Ab11685 91Ab149 / Prairie99Ab11787 91Ab2 / SP9-799Ab11813 Whitestone / 91Ab299Ab11862 92Ab390 / Whitestone99Ab11899 90Ab1322 / SP9-299Ab12179 90Ab1336 / Preakness99Ab12402 89Ab2861-1 / 88Ab3073 M399Ab12687 3073 / D-5 #4 53-5Ajay 74Ab1952 / 74Ab2608 Lamont 79Ab3811 / S 7884Maverick 80Ab988 / MonidaMonico 83Ab3119 / MonidaMonida Cayuse / OtanaOtana CI5345 / ZansterProvena Pennlo / PI 447276

Check cultivars CDC Boyer IA98822-2

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ID field plots for single isolate tests

Single isolate testsExperimental units = single hills

Field tests—naturally occurring inoculum

Entry   Field Test Location

    Louisiana Texas

    DLA (%) Classa DLA (%) Class

CDC Boyer (R check)   13.3 check 16.7 check

99Ab11862   18.3 R 20.0 R

IA 98822-2   35.0 R 11.7 R

99Ab12179   36.7 R 16.7 R

99Ab11813   56.7 S 26.7 R

95Ab11439   50.0 S 43.3 R

Monida   31.7 R 65.0 S

Monico   32.5 R 66.7 S

99Ab11468   53.3 S 55.0 S

89Ab3840   66.7 S 50.0 I

94Ab6965   66.7 S 56.7 S

98Ab7085   61.7 S 63.3 S

99Ab11685   56.7 S 73.3 S

99Ab11899   63.3 S 66.7 S

99Ab11787   65.0 S 66.7 S

Maverick   65.0 S 68.3 S

Ajay   80.0 S 55.0 S

Otana   80.0 S 56.7 S

99Ab12402   68.3 S 70.0 S

Lamont   80.0 S 63.3 S

99Ab12687   76.7 S 70.0 S

Provena (S check)   75.0 check 73.3 check

98Ab7399   80.0 S 70.0 S

95Ab12847   76.7 S 76.7 S

aR = not significantly different from the resistant check CDC Boyer by Dunnett's test (p = 0.05)

S = not significantly different from the susceptible check Provena by Dunnett's test (p = 0.05)

I = intermediate

Field tests—single isolate evaluations

R = not significantly different from the resistant check CDC Boyer by Dunnett's test (p = 0.05)

S = not significantly different from the susceptible check Provena by Dunnett's test (p = 0.05)

I = intermediate

Entry   Specific Isolates

    98MNB245 03MN111 CR185

    DLA (%) Classa DLA (%) Class DLA (%) Class

CDC Boyer (R check) 2.5 check 5.4 check 1.0 check

99Ab11862   0.9 R 12.6 R 0.3 R

IA 98822-2   4.3 R 4.1 R 3.0 R

99Ab12179   10.5 R 13.6 R 2.3 R

99Ab11813   0.4 R 13 R 1.4 R

95Ab11439   8.8 R 17 R 42.0 I

Monida   22.0 R 22 I 5.3 R

Monico   35.0 S 29 S 97.5 S

99Ab11468   23.8 R 29 S 15.0 R

89Ab3840   27.5 S 15.6 R 27.5 R

94Ab6965   52.5 S 26.2 S 87.5 S

98Ab7085   37.5 S 33 S 97.5 S

99Ab11685   8.3 R 12.6 R 5.3 R

99Ab11899   31.3 S 26 S 95.0 S

99Ab11787   23.8 R 40 S 100.0 S

Maverick   40.0 S 31 S 72.5 S

Ajay   23.8 R 27 S 32.5 R

Otana   25.0 S 37 S 100.0 S

99Ab12402   43.3 S 27 S 100.0 S

Lamont   30.0 S 33 S 97.5 S

99Ab12687   22.5 R 29 S 90.0 S

Provena (S check) 47.5 check 38 check 100.0 check

98Ab7399   47.5 S 44 S 100.0 S

95Ab12847   15.8 R 23 S 72.5 S

Greenhouse tests versus a spectrum of isolates

EntryResistance spectrum (%)a

CDC Boyer (R check) 100

99Ab11862 49

IA 98822-2 62

99Ab12179 60

99Ab11813 57

95Ab11439 100

Monida 100

Monico 100

99Ab11468 100

89Ab3840 80

94Ab6965 100

98Ab7085 96

99Ab11685 70

99Ab11899 98

99Ab11787 100

Maverick 100

Ajay 100

Otana 100

99Ab12402 100

Lamont 98

99Ab12687 94

Provena (S check) 100

98Ab7399 100

95Ab12847 100

aPercent compatible P. coronata isolates tested at the Cereal Disease Laboratory, n = 48

Provena

99Ab11862

95Ab11439

99Ab11813

99Ab12179

Leaf segment inoculation technique:

Greenhouse test for partial resistance

aNumbers within a column followed by the same letter are not significantly different by Tukey’s HSD test. Four isolates tested, no significant isolate by genotype interaction detected.

Genotype DLA (%)a FDNA (pg/mg oat tissue)

Provena 17.1 a 1208 a

99Ab11862 13.6 ab 623 b

99Ab12179 10.6 bc 696 b

95Ab11439 9.2 c 638 b

Conclusions

• Most of the Aberdeen cultivars and lines are highly susceptible to crown rust

• A few lines showed less disease in field trials– specific resistance to some isolates– partial resistance to compatible isolates in the

greenhouse, thus field response probably due to partial resistance