Germplasm Enhancement of Maize

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Project Description
Germplasm Screening
Materials & Methods
Results
Conclusions
References

GEM - 2005 Public Cooperator's Report

NOTE: The information in this report is shared cooperatively. The data are not published, but are presented with the understanding that they will not be used in publications without specific consent of the public cooperator.

 

Evaluation of Advanced GEM Lines for Multiple Insect Resistance and Fumonisin Concentration

Martin Bohn

University of Illinois, Urbana, Illinois

Project Description

The Western corn rootworm (WCR) and the European corn borer (ECB) are serious pests of maize in the U.S. Secondary infections with Fusarium fungi occur after ECB larvae feeding, causing ear rots and contamination with fumonisin, a mycotoxin associated with severe animal and human health disorders. The overall objective of this project is the development of maize varieties with host plant resistance (HPR) against WCR and ECB as well as an improved Fusarium resistance as major components of an integrated pest management system. The proposed research and breeding activities include an intensive evaluation and selection of germplasm developed from GEM breeding crosses for WCR, ECB, and Fusarium resistance. In additional step of this project the selected genotypes will be recombined and the genetic basis of the different resistances will be determined. The specific objectives are to (1) evaluate GEM lines for their resistance against WCR as well as first and second generation ECB, (2) evaluate GEM lines for their resistance against Fusarium species, (3) determine the association between insect resistance and Fumonisin concentration in GEM germplasm, (4) study the genetic basis of insect resistance in maize, and (5) initiate a recurrent selection program aimed to develop new maize lines with improved multiple insect resistant (MIR).

Germplasm Screening

The following GEM germplasm sets were evaluated in Urbana, IL, in 2005: (1) 40 S2 lines derived from GEM populations AR17056:N2025 and CUBA117:S1520 and S3 lines derived from S2 lines selected for their improved WCR resistance in 2004 for testcross and per se performance (SET 1), (2) a set of 60 hybrids representing a half diallel without parents derived from crosses between inbreds with improved levels of WCR resistance, WCR susceptible inbreds, and inbreds with known contrasting root characteristics (SET 2), (3) a set of factorial crosses between four WCR resistant inbreds, i.e., two GEM derived inbreds identified in this project and two inbreds developed by B. Hibbard (USDA-ARS, Columbia, Missouri) and five public and private inbreds (provided by AgReliant) (SET 3), and (4) 162 S2 lines derived from WCR-Breeding Program 2 (see below) (SET 4).   

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Materials and Methods

The testcrosses were produced by Pioneer and Syngenta. The factorial crosses were provided by AgReliant. The hybrids of the diallel experiment were produced in the UIUC summer nursery 2004. All experiments used a generalized lattice design with three to four replications and two-row plots. The trials were over-planted and thinned to 25 plants per row, corresponding to 65,000 plants ha-1. The experiments were planted May 6, 2005 (WCR experiments) and May 10, 2004 (all other experiments). The artificial infestation with first generation larvae was performed June 29 and 30, 2005. The artificial infestation with second generation larvae was performed August 8 and 9, 2005. The used infestation procedures were described in detail in the 2004 report. The WCR treatment was planted in a WCR trap crop area to ensure a high level of infestation. Damage to WCR larval root feeding was measured on five random plants per plot on July 12-18, 2005. All experiments were also repeated under insecticide protection.

The following resistance traits were determined: (1) leaf damage ratings (LDR) using a 1-9 rating scale, as defined by Guthrie and Barry (1989), (2) stalk damage ratings (SDR) using a 1-9 rating scale, as described by Hudon and Chiang (1991), and root damage ratings (RDR ) using the Iowa State 0-3 damage rating scale. The primary ear of each plant infested with ECB was hand harvested, dried, and the bulked seed was ground to facilitate the quantification of Fumonisin using the CD-ELISA method. We evaluated the following agronomic characteristics in all ECB infested and insecticide protected trials: (1) plant and ear height, cm, (2) female and male flowering, days, as well as (3) stalk and root lodging, percent. All hybrid evaluations were machine harvested and grain yield, bushels per acre, and grain moisture, in percent, were measured.

Results

SET1 - Testcross evaluation: In all testcross evaluation experiments significant (P < 0.05) differences between genotypes were detected for resistance traits RDR, LDR, and SDR, and agronomic characters (Table 1). The average RDR across all testcross evaluation experiments varied between 0.7 and 2.7 with a total average of 2.0. Mean LDR values ranged from 0.4 to 3.9 with a total mean of 2.5 and SDR means varied from 3.7 to 8.9 with a total mean of 6.4. Repeatabilities for all resistance traits varied between 27% (WCR, GEM:NSS×PHI_SS-TCs) to 52% (SDR, GEM:SS×PHI_NSS-TCs). On average the GEM:NSS-TCs showed less root damage than the GEM:SS-TCs. Testcrosses with GEM lines DKXL212.N11a01-05-1-2 (RDR = 0.69) and DKXL212.N11a01-02-5-2 (RDR=0.98) showed the lowest RDR. Five GEM:NSS-TCs  displayed significantly (P < 0.05) less root damage than the used commercial check hybrids. None of the evaluated GEM testcrosses were significantly better than the commercial checks with regard to their level of resistance to both generations ECB.

In 2004, a set of inbreds derived from GEM populations AR17056:N2025 and CUBA117:S1520 were artificially inoculated with Fusarium fungi. Fumonisin concentrations in the harvested grain were evaluated using the CD-ELISA method. We detected significant differences (P < 0.05) between GEM inbreds for fumonisin concentrations. However, in general fumonisin concentrations were low. The resistant check B73-001:31(x)-9 (kindly provided by Dr. White, UIUC) showed an average fumonisin concentration of 1.3 ppm and the GEM lines displayed varying fumonisin concentrations between 0.0 and 42.3 ppm with an overall mean of 4.4 ppm.

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SET 2 and SET 3 - Genetic Studies: We detected significant (P < 0.05) differences between diallel hybrids for RDR and root lodging. The hybrid RDR means varied between 1.10 (AR1705_3:Mo12) and 2.68 (Lo964:Lo1016) with an overall mean of 1.84. The mean root lodging values ranged from 4% to 84% with an overall mean of 40%. Significant (P < 0.05) differences between GCA effects and between SCA effects were found for RDR. For root lodging only significant (P < 0.05) SCA effects were observed. Inbred CUBA117:S1520-182-1-B-B showed the highest GCA effect for RDR (+0.60**) and the smallest GCA effects were observed for B64 (-0.29*) and Mo12 (-0.33*). Here, negative GCA effects indicate increased levels of WCR resistance. Two of the six crosses with significant SCA effects for RDR showed higher levels of WCR resistance (AR17056:N2025-522-1-B-B-B:AR17056:N2025  Select # 5-B-B and AR17056:N2025-522-1-B-B-B:Mo12). Both were also characterized by reduced root lodging percentages. Crosses containing GEM germplasm with significant SCA effects for reduced root lodging were AR17056:N2025-522-1-B-B-B:Mo12 and AR17056:N2025-522-1-B-B-B:NGSDCRW1. These results confirm observations from the factorial experiment. In this study AR17056:N2025-522-1-B-B-B showed the lowest average RDR across all cross combinations.

SET 4 - Evaluation of Breeding Material: Based on the observation in our experiments that root lodging and RDR are significantly correlated, we used root lodging information to perform selection in early generations. A set of 162 newly developed S2 lines were evaluated for root loading resistance under trap crop conditions using an incomplete block design with three replications. Among the 162 lines significant differences for root loading was observed. We selected 30 S2 lines with superior root loading resistance. The total set of 162 was also planted in the nursery for observing agronomic plant characteristics. The inbreeding process was continued for the selected 30 S2 lines.      

Germplasm Development

WCR-Program 1: The S3 lines selected in the summer nursery 2004 were selfed in the winter nursery 2004 and two to five ears per S3 line were planted ear to row in the 2005 WCR nursery. Within each row individual plants were selected and selfed (for more information about the selection process see report year 2004 - Activies 2004 – Germplasm Development). In a second step, whole S3 families were selected based on their testcross performance for WCR resistance (see Results – Evaluation of Breeding Material).

WCR-Program 2: A set of 61 S1 lines derived from four GEM populations and one CIMMYT populations were selfed in the winter nursery 2004. Between two to four selfed ears per S1 line were planted in the summer nursery 2005. Agronomic characteristics for each S2 lines were evaluated. S2 lines with improved WCR resistance (see Results - Testcross evaluation) were selfed.

WCR-Program 3: The base population formed to initiate a recurrent selection program for improving multiple insect resistance was planted a second time in isolation to allow for additional random mating and recombination. We harvested 300 ears. A random sample of these 300 ears will be used to start the selection program in the summer of 2006.

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Conclusions and Future Work

The growing season 2005 in East-Central Illinois was characterized by high temperatures and drought.  As in previous years, we observed high levels of WCR infestation. However, this year inbred performance was evaluated using testcrosses. This more vigorous germplasm showed a wide range of root damage levels and allowed a more accurate assessment of the putative potential of an inbred with regard to WCR resistance under high infestation levels. GEM line AR17056:N2025-522-1-B-B-B confirmed its increased level of WCR resistance in multiple experiments. Two hybrids derived from crosses between AR17056:N2025-522-1-B-B-B and two other inbreds showed improved WCR resistance and root lodging (see Results – Genetic Studies). F2 populations derived from these hybrids will be use to continue the WCR resistance breeding program. In addition, two new S3 lines derived from GEM population DKXL212.N11a01 (see WCR-Program 2) with improved levels of resistance to WCR were identified. Using a diallel design, it was possible to estimate GCA and SCA effects for RDR and root lodging. This experiment will be repeated in 2006 and will provide, together with QTL studies that we will conduct in collaboration with AgReliant and the USDA-ARS, Columbia, Missouri, using GEM material, further insights into the genetics of WCR resistance in maize. All WCR breeding programs will be continued in 2006.

References

Guthrie, W.D., and B.D. Barry. 1989. Methodologies used for screening and determining resistance in maize to the European corn borer. pp. 122-129. In CIMMYT. Toward insect resistant maize for the third world. Proc. Int. Symp. Methodologies for developing host plant resistance to maize insects. El Batan, CIMMYT, Mexico. CIMMYT, Int., CIMMYT, Mexico.

Hudon, M., and M.S. Chiang. 1991. Evaluation of resistance of maize germplasm to univoltine European corn borer Ostrinia nubilalis (Hübner) and relationship with maize maturity in Quebec. Maydica 36:69-74.


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Table 1      Mean root damage ratings (RDR), leaf damage ratings, and stalk damage ratings (SDR), for testcrosses of GEM derived inbreds in Urbana, Illinois, in 2005.

Pedigree

Tester1

RDR2

RLD

LDR

SDR

 

 

-- 0-3 --

--- % ---

---------- 1-9 ----------

DKXL212.N11a01-02-5-1 

PHI_SS

1.26

19.1

3.3

7.9

DKXL212.N11a01-02-5-3 

PHI_SS

2.40

30.0

1.2

6.7

DKXL212.N11a01-06-1-1 

PHI_SS

1.45

39.3

2.5

6.4

DKXL212.N11a01-06-1-2 

PHI_SS

1.66

37.6

1.8

7.3

DKXL212.N11a01-06-1-3 

PHI_SS

1.12

19.8

2.2

6.6

DKXL212.N11a01-06-1-4 

PHI_SS

1.50

37.7

1.9

6.8

DKXL212.N11a01-06-1-5 

PHI_SS

1.84

28.8

2.2

8.2

DKXL212.N11a01-09-3-1 

PHI_SS

1.59

25.0

2.3

6.5

DKXL212.N11a01-09-3-2 

PHI_SS

1.89

53.3

2.6

4.2

DKXL212.N11a01-09-3-4 

PHI_SS

1.55

26.1

2.4

6.7

DKXL212.N11a01-10-4-1 

PHI_SS

1.86

54.7

2.3

7.0

UR10001.N1708b-06-3-2 

PHI_SS

1.64

15.2

1.9

5.0

FS8AT.N1804-08-5-1 

PHI_SS

1.61

22.0

2.6

7.5

FS8AT.N1804-08-5-5 

PHI_SS

1.65

37.9

1.7

5.8

AR17056.N2025-532-1BBB 

PHI_SS

1.74

48.7

3.4

7.8

AR17056.N2025-546-1BBB 

PHI_SS

1.53

32.4

1.1

7.6

AR17056.N2025-522-1BBB 

PHI_SS

1.32

54.0

2.3

7.5

AR17056.N2025-728-1BBB 

PHI_SS

1.02

56.0

1.3

6.9

AR17056.N2025-535-1BBB 

PHI_SS

1.29

26.8

2.1

8.5

AR17056.N2025-540-1BBB 

PHI_SS

1.80

44.0

1.8

6.7

AR17056.N2025-607-1BBB 

PHI_SS

1.80

53.9

1.5

7.2

AR17056.N2025-507-1BBB 

PHI_SS

2.29

75.5

1.4

6.2

AR17056.N2025-757-1BBB 

PHI_SS

2.41

24.0

2.0

7.1

AR17056.N2025 1BB 

PHI_SS

2.13

60.2

2.0

7.8

AR17056.N2025 2BB 

PHI_SS

1.76

56.9

3.2

6.5

AR17056.N2025 3BB 

PHI_SS

1.86

40.7

1.9

6.2

AR17056.N2025 4BB 

PHI_SS

1.63

55.0

1.9

7.6

AR17056.N2025 5BB 

PHI_SS

1.98

52.2

1.8

7.0

AR17056.N2025 7BB 

PHI_SS

1.12

38.7

1.1

7.0

AR17056.N2025 8BB 

PHI_SS

1.17

44.0

2.1

7.9

AR17056.N2025 9BB 

PHI_SS

1.60

23.6

2.4

6.2

AR17056.N2025-574-1BB 

PHI_SS

1.31

60.6

2.4

7.1

AR17056.N2025-619-1BB 

PHI_SS

1.14

54.0

2.2

5.0

AR17056.N2025-685-1BB 

PHI_SS

2.44

57.5

2.1

5.5

AR17056.N2025-697-1BB 

PHI_SS

2.08

54.5

1.2

6.3

DKXL212.N11a01-02-5-2 

PHI_SS

0.98

38.6

 

 

DKXL212.N11a01-05-1-1 

PHI_SS

1.81

5.0

 

 

DKXL212.N11a01-05-1-2 

PHI_SS

0.69

34.8

 

 

DKXL212.N11a01-09-3-3 

PHI_SS

1.83

37.2

 

 

DKXL212.N11a01-09-3-5 

PHI_SS

1.26

42.2

 

 

DKXL212.N11a01-10-4-3 

PHI_SS

1.19

25.1

 

 

UR10001.N1708b-06-3-1 

PHI_SS

1.69

60.7

 

 

FS8AT.N1804-08-5-3 

PHI_SS

1.20

25.3

 

 

FS8AT.N1804-08-5-4 

PHI_SS

1.69

16.7

 

 

AR17056.N2025-508-1BBB 

PHI_SS

1.68

49.3

 

 

AR17056.N2025 6BB 

PHI_SS

1.90

46.0

 

 

AR17056.N2025-596-1BB 

PHI_SS

1.58

51.8

 

 

AR17056.N2025-624-1BB 

PHI_SS

1.73

58.5

 

 

T236-015.1158-4 

PHI_SS

1.69

31.6

 

 

A619 

PHI_SS

1.60

51.0

1.3

7.3

Mo17 

PHI_SS

1.70

55.1

2.7

6.8

33N56

CHECK

2.13

46.5

2.1

6.6

33K39

CHECK

1.96

20.9

2.2

6.7

33A84

CHECK

1.92

43.6

2.5

7.0

33N09

CHECK

1.95

39.2

2.7

6.5

33D31

CHECK

2.06

54.4

2.7

5.1

32P75

CHECK

1.73

28.8

1.6

5.6

31N27

CHECK

1.96

41.0

2.1

5.7

 

 

 

 

 

 

Mean

 

1.67

41.22

2.1

6.7

LSD 5%

 

1.62

41.0

2.04

6.8

Repeatability 1%

 

27.6

12.8

28.7

39.1

 

 

 

 

 

 

AR17056.S1216-02-1-1 

PHI_NSS

1.81

47.15

2.80

5.97

AR17056.S1216-02-1-2 

PHI_NSS

1.56

44.98

3.10

7.24

AR17056.S1216-02-1-3 

PHI_NSS

2.13

49.71

2.76

6.78

AR17056.S1216-02-1-4 

PHI_NSS

2.41

62.97

2.43

3.78

AR17056.S1216-02-1-5 

PHI_NSS

2.00

35.74

1.41

6.05

AR17056.S1216-02-5-1 

PHI_NSS

2.29

42.17

1.36

6.32

AR17056.S1216-02-5-2 

PHI_NSS

2.07

38.78

1.78

5.73

AR17056.S1216-02-5-3 

PHI_NSS

2.26

44.71

1.65

6.06

AR17056.S1216-02-5-4 

PHI_NSS

2.34

45.23

1.69

7.19

CUBA117.S1520-52-1BB 

PHI_NSS

2.06

69.84

1.50

5.52

CUBA117.S1520-153-1BB 

PHI_NSS

1.97

52.79

2.66

6.34

CUBA117.S1520-156-1BB 

PHI_NSS

2.54

70.11

1.59

6.55

CUBA117.S1520-182-1BB 

PHI_NSS

2.18

48.54

1.94

7.32

CUBA117.S1520-388-1BB 

PHI_NSS

1.80

39.74

1.95

5.32

CUBA117.S1520-411-1BB 

PHI_NSS

2.36

41.29

1.94

7.60

CUBA117.S1520-430-1BB 

PHI_NSS

1.98

31.53

2.01

6.72

CUBA117.S1520-562-1BB 

PHI_NSS

1.96

59.03

1.75

7.86

B73-001.31x-9 

PHI_NSS

2.23

37.64

1.99

5.84

B37 

PHI_NSS

2.42

62.21

0.38

6.09

B73 

PHI_NSS

2.05

26.88

2.55

6.22

DE811 

PHI_NSS

2.09

71.92

2.37

7.18

33N56

CHECK

1.55

17.96

2.55

7.73

33K39

CHECK

1.43

41.54

3.25

5.01

33A84

CHECK

1.92

45.70

1.86

5.89

33N09

CHECK

1.70

54.36

2.81

7.57

33D31

CHECK

1.67

48.15

2.50

8.94

32P75

CHECK

1.40

44.19

2.62

5.54

31N27

CHECK

1.96

49.96

2.67

5.57

32W86

CHECK

2.45

52.15

2.45

6.65

33M54

CHECK

2.11

64.36

1.80

7.62

 

 

 

 

 

 

Mean

 

1.95

47.43

2.23

6.42

LSD5%

 

0.54

28.54

1.16

1.82

Repeatability 1%

 

42.5

15.2

50.0

51.9

 

 

 

 

 

 

AR17056:N2025-532-1-B-B-B

SYN_SS

2.53

63.1

 

 

AR17056:N2025-546-1-B-B-B

SYN_SS

2.61

60.6

 

 

AR17056:N2025-522-1-B-B-B

SYN_SS

2.26

76.4

 

 

AR17056:N2025-728-1-B-B-B

SYN_SS

2.32

51.1

 

 

AR17056:N2025-508-1-B-B-B

SYN_SS

2.09

70.5

 

 

AR17056:N2025-535-1-B-B-B

SYN_SS

2.42

55.1

 

 

AR17056:N2025-540-1-B-B-B

SYN_SS

2.52

81.6

 

 

AR17056:N2025-607-1-B-B-B

SYN_SS

2.60

57.1

 

 

AR17056:N2025-507-1-B-B-B

SYN_SS

2.52

76.1

 

 

AR17056:N2025-553-1-B-B-B

SYN_SS

2.36

69.3

 

 

AR17056:N2025-757-1-B-B-B

SYN_SS

2.54

49.9

 

 

AR17056:N2025  Select # 1-B-B

SYN_SS

2.52

78.3

 

 

AR17056:N2025  Select # 2-B-B

SYN_SS

1.94

55.2

 

 

AR17056:N2025  Select # 3-B-B

SYN_SS

2.28

82.6

 

 

AR17056:N2025  Select # 4-B-B

SYN_SS

2.43

71.1

 

 

AR17056:N2025  Select # 5-B-B

SYN_SS

2.43

80.5

 

 

AR17056:N2025  Select # 6-B-B

SYN_SS

2.58

62.4

 

 

AR17056:N2025  Select # 7-B-B

SYN_SS

1.87

58.8

 

 

AR17056:N2025  Select # 8-B-B

SYN_SS

2.40

82.9

 

 

AR17056:N2025  Select # 9-B-B

SYN_SS

2.12

62.6

 

 

AR17056:N2025  Select # 10-B-B

SYN_SS

1.88

51.5

 

 

AR17056:N2025-522-1-B-B

SYN_SS

2.37

78.8

 

 

AR17056:N2025-540-1-B-B

SYN_SS

2.08

62.9

 

 

AR17056:N2025-546-1-B-B

SYN_SS

2.16

74.6

 

 

AR17056:N2025-566-1-B-B

SYN_SS

2.59

73.3

 

 

AR17056:N2025-574-1-B-B

SYN_SS

2.17

63.5

 

 

AR17056:N2025-596-1-B-B

SYN_SS

2.51

77.9

 

 

AR17056:N2025-619-1-B-B

SYN_SS

2.61

75.9

 

 

AR17056:N2025-624-1-B-B

SYN_SS

2.57

76.8

 

 

AR17056:N2025-685-1-B-B

SYN_SS

2.03

64.2

 

 

AR17056:N2025-697-1-B-B

SYN_SS

2.14

42.1

 

 

 

 

 

 

 

 

CUBA117:S1520-41-1-B-B

SYN_NSS

2.29

70.5

 

 

CUBA117:S1520-52-1-B-B

SYN_NSS

2.41

66.2

 

 

CUBA117:S1520-153-1-B-B

SYN_NSS

2.20

54.4

 

 

CUBA117:S1520-156-1-B-B

SYN_NSS

1.39

47.8

 

 

CUBA117:S1520-182-1-B-B

SYN_NSS

2.26

64.5

 

 

CUBA117:S1520-298-1-B-B

SYN_NSS

2.02

58.2

 

 

CUBA117:S1520-388-1-B-B

SYN_NSS

2.28

76.9

 

 

[NGSDCRW1(S2)-C4

SYN_NSS

2.03

53.3

 

 

33D31

 

2.13

61.9

 

 

34H31

 

2.08

67.6

 

 

RX708YG/RW

 

0.93

0.0

 

 

RX708

 

2.72

64.3

 

 

DKC63-78

 

2.10

48.3

 

 

 

 

 

 

 

 

Mean

 

2.28

65.3

 

 

LSD 5%

 

0.51

26.7

 

 

Repeatability 1%

 

30.0

6.0

 

 

1          PHI_SS = Pioneer Hibred tester from the Stiff Stalk heterotic pool; PHI_NSS = Pioneer Hibred tester from the Non-Stiff Stalk heterotic pool. SYN_SS = Syngenta tester from the Stiff Stalk heterotic pool; SYN_NSS = Pioneer Hibred tester from the Non-Stiff Stalk heterotic pool.

2          RDR = Iowa State root damage ratings; RLD = Root lodging (%), LDR = Leaf damage rating, (1 = no damage, 9 = long lesions on most leaves); SDR = Stalk damage rating (1= no damage, 9 = stalk broken below ear) evaluated for plants manual infested at 2nd brood ECB moths appearance.

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Contact us | Home | USDA | ARS | NCRPIS | ISU | Corn Breeding | January 19, 2006