evaluation of round-up ready soybean cultivars for ...evaluation of round-up ready soybean cultivars...

Evaluation of Round-Up Ready Soybean Cultivars for Resistance toXanthomonas axonopodis pv. glycines

L. D. Goradia1, S.L. Daniel1, and G. L. Hartman2

1Eastern Illinois University Charleston, IL 61920 and 2University of Illinois at Urbana-Champaign, IL 61802

Table 1. Sixty-six (66) soybean cultivarswere highly susceptible.

Table 2. Forty-one (41) soybeancultivars were moderately susceptible.

Table 3. Forty-four (44) soybeancultivars were less susceptible.

43NAPi 520.733

40.75DSR-228 RRDAIRYLAND

41.254410 SCNSTEYER

43K-282-2 RRKRUGER

43.5RICHMOND VIRRMERSCHMAN

44.258314 RREXCEL

44.5EX-1097 RRLATHAM

45.25V 282 RRVIGORO

45.75K-286 RRKRUGER

46K-323 RRKRUGER

47.258410 NRREXCEL

47.75285 CRRMWS

48.25SS 2618HENKEL

48.25H 3505 RRGOLDEN HARVEST

49.5TRISOY 3017 RRNTRISLER

50.5HS 4107FS HISOY

51V 442 NRRVIGORO

51.25271.RPWSCHILLINGER

51.2593B67PIONEER

51.5K-330 RR/SCNKRUGER

54K-330 RRKRUGER

55.253800-4STINE

55.5551 RRHUGHES

55.75KB 244 RRKALTENBERG

55.758395 RREXCEL

56.752803 RRSIEBEN

57C 48009 RNCROW'S

57AG 4403ASGROW

57.5V 363 NRRVIGORO

57.75DG 3370 RRUAP

57.75437 NRRBECK

59.25K-262-2 RRKRUGER

61.25V 272 NRRVIGORO

61.25K-323-3 RRKRUGER

61.5DSR-395 RRDAIRYLAND

61.54425 CRRBAKER

61.75DSR-322 RRDAIRYLAND

62.53808-4STINE

638234 RREXCEL

63.5CHEROKEE XRRMERSCHMAN

63.58195 RREXCEL

642463-4STINE

64HS 3706FS HISOY

65K-300 RRKRUGER

65.253101 RRSTRIKE

66.75H 3983 RRGOLDEN HARVEST

67283 RRBECK

67.5667 RRLATHAM

67.75RT 4495 NSOUTHERN STATES

69.25K-444 RR/SCNKRUGER

70US S2709 RRUNITED SUPPLIERS

70.754505 CRRBAKER

71.5TRISOY 3217 RRNTRISLER

74.52820 RRDERAEDT

76.25SP 3400 RRSUN PRAIRIE

76.25321.RCSCHILLINGER

76.25DKB 44-51DEKALB

76.75HS 3005FS HISOY

842801 RRSTRIKE

84.252582 RRWILKEN

85.5RT 4098SOUTHERN STATES

85.75211.RWSCHILLINGER

87EX 292 NWILLCROSS

888254 RREXCEL

89.75DPX 4300 RRDELTA & PINE LAND

94.25R 4268 RRROESCHLEY

104.253402 RRWILKEN

160.5DST 2129 RRDAIRYLAND

Average # of pustules/plantCompanyName

18.5NAWilliams 82

21.75K-255 RRKRUGER

20.752736-4STINE

20.75CHICKASAW VIIRRMERSCHMAN

21.25RT 4585FS HISOY

22.254202-4STINE

22.5DKB 28-51DEKALB

23.54965 RRDELTA KING

23.75DKB 23-51DEKALB

24.25XTJ 174 RRDELTA KING

24.75K-222+ RRKRUGER

24.75BG 4401 NRRBIO GENE

26BT 351 RBERGMANN-TAYLOR

27.5RR 2331 NWILLCROSS

27.75PB-2861 RRPRAIRIE BRAND

28WE 944 RRWILKEN

28.5K-262 RR/SCNKRUGER

29.25281.RIPSCHILLINGER

29.75331.RCPSCHILLINGER

302568 RRWILKEN

30DKB 26-51DEKALB

30.753461 NRRWILKEN

31.25RR 2242WILLCROSS

31.25250.RPBSCHILLINGER

31.5DG 3468 NRRUAP

31.75HS 2906FS HISOY

32.5GL 3409 RRGREAT LAKES

32.75K-388+ RRKRUGER

34.25H 2871 RRGOLDEN HARVEST

34.752691 NRRWILKEN

35DSR-232 RRDAIRYLAND

35.5K-289 RRKRUGER

35.752583 RRWILKEN

36.5EX-787 RRLATHAM

37DG 3278 RRUAP

37.5K-443-3 RR/SCNKRUGER

38.25PB-2841 RRPRAIRIE BRAND

38.75H 328 NRRHORIZON

39SP 3702 NRRSUN PRAIRIE

39BT 400 CRBERGMANN-TAYLOR

39.2593B85PIONEER

39.5DG 3484 NRRUAP

39.7594B23PIONEER

43NAPi 520.733

Average # ofpustules/plantCompanyName

1.75DKB 32-52DEKALB

1.5GR 3331MIDWEST SEED GEN

1.55366 RRDELTA KING

1.75K-252+ RRKRUGER

2.25SHAWNEE VIIIRRMERSCHMAN

2.53551 NRRWILKEN

3AG 2402ASGROW

3.53471 NRRWILKEN

3.75EXCEL 8274 RRNAGRINETICS

4.5H 3960 RRGOLDEN HARVEST

4.75K-250-1 RRKRUGER

4.75X 2515FS HISOY

5DSR-268 RRDAIRYLAND

6RS 310 RRRENK

6.25KENNEDY VIRRMERSCHMAN

6.5367 NRRBECK

7.25PB-3404 RRPRAIRIE BRAND

7.75K-255-5 RRKRUGER

8.258306 RREXCEL

8.75RR 2350WILLCROSS

8.75KSC 3926 CRRKITCHEN

8.75H 379 RRHORIZON

10.5US S2101 RRUNITED SUPPLIERS

11.75US E3802 RRUNITED SUPPLIERS

123403 RRWILKEN

12ROOSEVELT IIIRRMERSCHMAN

12.75DKB 45-51DEKALB

13RT 3585FS HISOY

13.5X 2815FS HISOY

14.25EX-747 RRNLATHAM

14.25DSR-290 RRDAIRYLAND

14.5V 393 NRRVIGORO

14.5310.RPSCHILLINGER

15K-444-4 RR/SCNKRUGER

158484 RREXCEL

15.25DSR-272 RRDAIRYLAND

15.75XP 3132 RRSUN PRAIRIE

17.253498 RRWILKEN

17.254762 RRDELTA KING

17.25DKB 40-51DEKALB

17.5RR 2392 NWILLCROSS

18AG 2703ASGROW

18.252318 RRWILKEN

19.5RR 2321 NWILLCROSS

18.5NAWilliams 82

Average # ofpustules/plantCompanyName

Introduction

Bacterial pustule is caused by the bacteriumXanthomonas axonopodis pv. glycines. It is mostprevalent in soybean growing areas, especially incountries like Australia, China, India, Japan, Korea,Sudan and the United States. X. axonopodis pv.glycines is a gram negative, aerobic rod shapedbacterium.

Bacterial pustule occurs primarily on the foliage ofsoybeans. The first symptoms are small, yellow-green spots with reddish-brown centers on theupper leaf surface (Figure 1) . In later stages dried,broken remnants of pustule may be seen on smallnecrotic areas bordered by narrow yellow halos.

A very high level of resistance to bacterial pustuledisease is conferred by a recessive genedesignated rxp, originally found in soybean cultivarCNS.

Objective

The objective of this study was to screen Round-up® ready soybean cultivars for resistance to X.axonopodis pv. glycines.

Method

Round-up® ready soybean cultivars (525) weregrown in the greenhouse for 14-20 days inuniversal soil mix. Plants were sprayed with X.axonopodis pv. glycines inoculum. The culture wasgrown in Potato dextrose broth at 25oC for 8h. Theinoculum size was adjusted to 108 viable cells/mI.The first trifoliates were damaged by a perforationneedle. Inoculation was done by spraying theinoculum using an atomizer attached tocompressed air-line (Figure 2). Results wererecorded after 7 days by counting the number ofpustules on heavily infected trifoliate leaves (Figure3). The susceptible varieties were tested again andthe experiment was duplicated.

Results

Of the 525 Round-up® ready soybean cultivarsscreened, 152 cultivars (~28%) were found to besusceptible to X. axonopodis pv. glycines andformed pustule.

Under standard greenhouse conditions, theaverage number of pustules per plant was 43 and18 for susceptible control (P1 520.733) theresistant control (Williams 82), respectively

When the 152 susceptible cultivars were testedagain, 66 were found to be highly susceptible,based on the observation that these cultivarsaveraged more pustules per plant than thesusceptible control (Table1).

Forty-one (41) cultivars were found to bemoderately susceptible based on the observationthat the average number of pustules per plant fellbetween the range of susceptible and resistantcontrols (Table 2).

Forty-four (44) cultivars were found to be lesssusceptible, based on the observation that thesecultivars averaged less pustules per plant than theresistant control (Table 3).

Conclusions

These results suggest that resistance is not being maintained in commercial soybean cultivars which maylead to an increased incidence of bacterial pustule in the field, thus impacting soybean yields.

Further research calls for detecting if the rxp gene is inserted in these soybean cultivars.

Acknowledgement

I would like to thank Dr. Hartmari for the facilities and Ron Warsaw for his help in acquiring seeds and TheLewis Hanford Tiffany Botany Graduate Research Fund for funding.

References

1. Hartman, G.L. et. al., ed. 1999. Compendium ot Soybean Diseases. APS Press. 2. Hartwig, E.E and S.G. Lehman. Agron Journal. 43:226-229. 1951. 3. Oh, C., S. Heu, and Yong-Chul Choi. Plant Pathol. J. 15(1):57-61. 1999.