Genetic stocks developed and maintained by the USDA-ARS Cereal Crops Research Unit, Fargo, ND.

For inquiries and requests:
Justin Faris (farisj@fargo.ars.usda.gov)
Steven Xu (xus@fargo.ars.usda.gov)

Summary of stocks maintained:
Langdon-T. dicoccoides substitution lines: 39
Langdon-T. dicoccoides homozygous recombinant mapping populations: 15
Langdon D-genome substitution lines: 14
Langdon-Ae. tauschii synthetics: 45
Durum 1AS-1AL.1DL translocation lines: 4
Triticale D-genome substitution lines: 10

Langdon durum-T. turgidum spp. dicoccoides disomic substitution lines.
Three sets of Langdon durum-T. turgidum var. dicoccoides (LDN-DIC) substitution lines were developed by Dr. Leonard R. Joppa using T. turgidum ssp. dicoccoides (DIC) accessions Israel-A, PI-481521 and PI-478742 as the chromosome donor in Langdon background (Table 1). In these lines, a pair of chromosomes from DIC was substituted for a pair of native homologous chromosomes in LDN. The LDN-DIC lines were produced by crossing each Langdon durum D-genome disomic substitution line (LDN D-genome DS) as female to each of three DIC accessions. Five to seven backcrosses were made to the LDN D-genome DS to restore the LDN genetic background, while retaining a single chromosome from DIC as a monosome. The LDN-DIC lines were selected after one generation of self-pollination of BC5 to BC7 plants. The sets based on PI-481521 and Israel-A have all 14 chromosome substitutions. But, three substitutions (2A, 3A, and 3B) in the set based on PI-478742 are not available.

LDN-DIC recombinant inbred chromosome substitution lines (RICLs).
Homozygous recombinant populations were developed by crossing each of the available LDN-DIC (Israel A accession) substitution lines with LDN as described in Joppa (1997; Crop Science 33:908-913). Maps have been generated for some of the populations (see Table 2). In addition, recombinant inbred line populations have been developed for the LDN-DIC 5B (PI478742) and LDN-DIC 7A (PI478742) lines.

Langdon D-genome substitution lines.
The Langdon D-genome substitutions were developed by crossing the Chinese Spring nullisomic-tetrasomic series to Langdon durum wheat. The Chinese Spring (CS) aneuploids have four copies of a chromosome and have zero copies of a homoeologous chromosome. Thus, CS-nulli-1A, tetra-1D can be crossed to Langdon durum, a tetraploid that does not have the D-genome chromosomes. The F1 from this cross has 14 pairs of chromosomes, including a pair of 1D chromosomes. It also has 7 univalent chromosomes including a monosome for 1A. Selfing and selecting will result in plants with 14 pairs of chromosomes and no monosomics. These plants will be disomic for 1D and nullisomic for 1A. All possible combinations of plants with the disomic D-genome chromosomes and nullisomic for the A- and B-genome homoeologues were obtained.

In order to eliminate the genes contributed to the A- and B-genomes by the CS parent, the plants were backcrossed to Langdon 12 times. It is hoped that almost all contribution to these lines from CS has been eliminated except for the contribution of the homozygous D-genome chromosomes.

In some cases, the D-genome chromosomes fail to completely compensate for the loss of the homoeologous A- or B-genome chromosomes. A description of these lines follows. If a line is not mentioned, it should be assumed that it is normal.
LDN-4D(4A)
The plants nullisomic for chromosome 4A do not germinate and no plants of this constitution have ever been observed. The line is maintained as 13” + 1”4D + 1’4A. Selfing these plants results in plants like the parent except for occasional plants with 15” (4D disomic additions). These plants should always be used as the female in crosses and the progeny will almost always be 13” + 2’ (i.e. mono-4A, mono-4D).
LDN-5D(5A)
Plants nullisomic for chromosome 5A have very low fertility. Consequently, this line is maintained as disomic for 5D and monosomic for 5A. The 14” + 1’ plants produce progeny like the parent (i.e. 14” + 1’). There are occasional 15” plants. We usually discard these plants using root tip analysis of seedlings.
LDN-3D(3B)
Sears reported that chromosome 3B contains a gene that is necessary to prevent asynapsis at MI of meiosis. The 3D(3B) line must have the short arm of 3B and we maintain the line as the disomic 3D, monosomic 3B. Transmission of the 3B chromosome is low. Thus, it is necessary to look at root tips to find plants with the 3B monosome. It is possible to obtain plants that are disomic for both 3D and 3B, but they are abnormal and very hard to maintain. We continue to search for better plants and for plants with a telosomic 3B chromosome.
LDN-5D(5B)
The Ph1 gene is on the long arm of chromosome 5B. When this gene is absent, pairing between non-homologous chromosomes is observed. Selfing plants nullisomic for chromosome 5B results in the line running out after a few generations; due to translocations, duplications, and deficiencies. The line is maintained as disomic for 5D and monosomic for 5B. Transmission of the monosomic 5B chromosome averages about 50 percent in selfed plants.
LDN-6D(6B)
Plants nullisomic for 6B and disomic for 6D have very low fertility. Examination of the heads reveals that many of the anthers resemble pistils (i.e. plants are pistilloid). We maintain this line with a telosomic 6BS chromosome. Transmission of the 6BS telosome through the male gamete is close to 100 percent. Occasional plants disomic for 6BS are observed. Because of the male transmission of this telo, crosses should be made with the 6D(6B) line as the female. The telo is seldom transmitted through female gametes.
LDN-7D(7B)
The group 7 chromosomes have genes governing chlorophyll production. Chromosome 7D does not completely compensate for either 7A or 7B, but the problem is greater in the case of 7B. The plants tend to be somewhat weak. At heading the leaves develop a progressive necrosis that eventually leads to plant death. This does not occur before the plants set seed. It is sometimes difficult to obtain pollen for crossing. Seed production is adequate for most purposes.

Langdon durum-Aegilops tauschii synthetic hexaploid wheat.
Dr. Joppa developed a number of spontaneous synthetic hexaploid wheat from partially fertile hybrids between LDN and different Ae. tauschii accessions in 1980s. We recently developed three new synthetic lines from the crosses between LDN and Ae. tauschii accessions PI 476874 (tough rachis), CIae19, and AL8/78. Some Ae. tauschii accessions were received from National Small Grains Collection (NSGC), Aberdeen, Idaho, others were provided respectively by Dr. E.R. Kerber (Agriculture and Agri-Food Canada, Winnipeg, Manitoba, Canada), Dr. E. Nevo (University of Haifa, Haifa, Israel), and Dr. B. Keller (University of Zurich, Zurich, Switherland). Except that the synthetic line from cross LDN/PI 268210 was named as Largo and released as greenbug-resistant germplasm, other lines have not been characterized previously. These synthetics have recently been evaluated for resistance to tan spot, Stagonospora leaf blotch, leaf and stem rust, and Hessian fly. We are currently evaluating their resistance to FHB and seed storage protein compositions. The synthetics that are available for seed distribution are listed in Table 3.

Durum wheat 1AS.1AL-1DL translocation lines carrying Glu-D1d

Four translocation lines having the pedigree Langdon1D(1A)/Len//Langdon/3/2*Renville and carrying glutenin subunits 1Dx5 and 1Dy10 from the Glu-D1d allele are available. These lines were produced in an effort to develop dual-purpose (good baking and pasta quality) durum wheat. The lines are identified as L092, L252, S99B33, and S99B34. Three of the lines carry the LMWII banding pattern derived from Renville and conditioned by the Glu-B3 gene. The fourth line, L252, carries the LMWI banding pattern derived from Langdon. Quality tests have indicated L252 has better mixing traits and slightly better loaf volume than the translocation lines carrying LMWII. In trials conducted in North Dakota from 2000-2002, S99B33 and S99B34 were the highest yielding of the translocation lines and similar in yield to Renville. These lines should be useful to breeders attempting to produce dual-purpose durum or for cereal chemists studying effects of Glu-D1d in a durum background.

Hexaploid triticale D-genome disomic substitution lines.

A partial set of 10 hexaploid triticale D-genome disomic substitution lines except for 2D(2A), 5D(5A), 3D(3B), and 5D(5B) were developed from crosses between Langdon durum D-genome disomic substitution lines and ‘Gazelle’ rye (Table 3). The triticale substitution lines 4D(4A) and 6D(6B) were produced from colchicine treatment of F1's and other eight lines were selected from partially fertile F1's. Most of the triticale D-genome substitutions had reduced seed fertility except that 1D(1A), 1D(1B), and 7D(7B) substitutions had the same high level of fertility as the LDN triticale. Because these hexaploid triticale D-genome disomic substitutions have a uniform genetic background, they could be used to evaluate the effects of each of the D-genome chromosomes on economically important traits of hexaploid triticale, such as grain shriveling, seed quality, and productivity.


Table 1. Designations for the 38 LDN-DIC disomic chromosome substitution lines.

Chromosome

Abbreviated designations for:

Israel-A

PI481521

PI478742

1A

LDN-DIC 1A(IsA)

LDN-DIC 1A(521)

LDN-DIC 1A(742)

2A

LDN-DIC 2A(IsA)

LDN-DIC 2A(521)


3A

LDN-DIC 3A(IsA)

LDN-DIC 3A(521)


4A

LDN-DIC 4A(IsA)

LDN-DIC 4A(521)

LDN-DIC 4A(742)

5A

LDN-DIC 5A(IsA)

LDN-DIC 5A(521)

LDN-DIC 5A(742)

6A

LDN-DIC 6A(IsA)

LDN-DIC 6A(521)

LDN-DIC 6A(742)

7A

LDN-DIC 7A(IsA)

LDN-DIC 7A(521)

LDN-DIC 7A(742)

1B

LDN-DIC 1B(IsA)

LDN-DIC 1B(521)

LDN-DIC 1B(742)

2B

LDN-DIC 2B(IsA)

LDN-DIC 2B(521)

LDN-DIC 2B(742)

3B

LDN-DIC 3B(IsA)

LDN-DIC 3B(521)


4B

LDN-DIC 4B(IsA)

LDN-DIC 4B(521)

LDN-DIC 4B(742)

5B

LDN-DIC 5B(IsA)

LDN-DIC 5B(521)

LDN-DIC 5B(742)

6B

LDN-DIC 6B(IsA)

LDN-DIC 6B(521)

LDN-DIC 6B(742)

7B

LDN-DIC 7B(IsA)

LDN-DIC 7B(521)

LDN-DIC 7B(742)





Table 2. Langdon-T. dicoccoides (LDN-DIC) recombinant inbred chromosome line (RICL) populations.

Population

No. Lines

LDN-DIC 1A(IsA) HR

92

LDN-DIC 1B(IsA) HR

93

LDN-DIC 2A(IsA) HR

107

LDN-DIC 3A(IsA) HR

83

LDN-DIC 3B(IsA) HR

91

LDN-DIC 4A(IsA) HR

136

LDN-DIC 4B(IsA) HR

117

LDN-DIC 5A(IsA) HR

95

LDN-DIC 5B(IsA) HR

136

LDN-DIC 6A(IsA) HR

89

LDN-DIC 6B(IsA) HR

85

LDN-DIC 7A(IsA) HR

166

LDN-DIC 7B(IsA) HR

148

LDN-DIC 5B(742) RI

125

LDN-DIC 7A(742) RI

125


Table 3. Langdon durum-Aegilops tauschii synthetic hexaploid wheat

Line No.

Pedigree

Source of Ae. tauschii

1

Langdon/Ae. tauschii CIae 1

NSGC, Aberdeen, Idaho

2

Langdon/Ae. tauschii CIae 5

NSGC, Aberdeen, Idaho

3

Langdon/Ae. tauschii CIae 9

NSGC, Aberdeen, Idaho

4

Langdon/Ae. tauschii CIae 11

NSGC, Aberdeen, Idaho

5

Langdon/Ae. tauschii CIae 14

NSGC, Aberdeen, Idaho

7

Langdon/Ae. tauschii CIae 22

NSGC, Aberdeen, Idaho

8

Langdon/Ae. tauschii CIae 25

NSGC, Aberdeen, Idaho

9

Langdon/Ae. tauschii CIae 26

NSGC, Aberdeen, Idaho

10

Langdon/Ae. tauschii H80-101-4

Haifa, Israel

11

Langdon/Ae. tauschii H80-114-1

Haifa, Israel

12

Langdon/Ae. tauschii H80-115-3

Haifa, Israel

13

Langdon/Ae. tauschii PI 220331

NSGC, Aberdeen, Idaho

14

Langdon/Ae. tauschii PI 220641

NSGC, Aberdeen, Idaho

15

Langdon/Ae. tauschii PI 317392

NSGC, Aberdeen, Idaho

16

Langdon/Ae. tauschii RL 5003

Winnipeg, Manitoba, Canada

17

Langdon/Ae. tauschii RL 5214

Winnipeg, Manitoba, Canada

19

Langdon/Ae. tauschii RL 5259

Winnipeg, Manitoba, Canada

20

Langdon/Ae. tauschii RL 5261

Winnipeg, Manitoba, Canada

21

Langdon/Ae. tauschii RL 5263

Winnipeg, Manitoba, Canada

22

Langdon/Ae. tauschii RL 5266-1

Winnipeg, Manitoba, Canada

23

Langdon/Ae. tauschii RL 5271

Winnipeg, Manitoba, Canada

24

Langdon/Ae. tauschii RL 5272

Winnipeg, Manitoba, Canada

25

Langdon/Ae. tauschii RL 5286

Winnipeg, Manitoba, Canada

26

Langdon/Ae. tauschii RL 5392

Winnipeg, Manitoba, Canada

27

Langdon/Ae. tauschii RL 5393

Winnipeg, Manitoba, Canada

28

Langdon/Ae. tauschii RL 5492

Winnipeg, Manitoba, Canada

29

Langdon/Ae. tauschii RL 5498

Winnipeg, Manitoba, Canada

30

Langdon/Ae. tauschii RL 5527

Winnipeg, Manitoba, Canada

32

Langdon/Ae. tauschii RL 5532

Winnipeg, Manitoba, Canada

34

Langdon/Ae. tauschii RL 5544

Winnipeg, Manitoba, Canada

35

Langdon/Ae. tauschii RL 5552

Winnipeg, Manitoba, Canada

36

Langdon/Ae. tauschii RL 5555

Winnipeg, Manitoba, Canada

37

Langdon/Ae. tauschii RL 5557

Winnipeg, Manitoba, Canada

38

Langdon/Ae. tauschii RL 5560

Winnipeg, Manitoba, Canada

39

Langdon/Ae. tauschii RL 5561

Winnipeg, Manitoba, Canada

40

Langdon/Ae. tauschii RL 5562

Winnipeg, Manitoba, Canada

41

Langdon/Ae. tauschii RL 5570

Winnipeg, Manitoba, Canada

44

Langdon/Ae. tauschii PI 476874

NSGC, Aberdeen, Idaho

52

Langdon/Ae. tauschii CIae 17

NSGC, Aberdeen, Idaho

53

Langdon/Ae. tauschii PI 268210

NSGC, Aberdeen, Idaho

55

Langdon/Ae. tauschii RL 5257

Winnipeg, Manitoba, Canada

56

Langdon/Ae. tauschii RL 5258

Winnipeg, Manitoba, Canada

57

Langdon/Ae. tauschii RL 5270

Winnipeg, Manitoba, Canada

58

Langdon/Ae. tauschii AL8/78

Zurich, Switzerland

59

Langdon/Ae. tauschii CIae 19

NSGC, Aberdeen, Idaho