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United States Department of Agriculture

Agricultural Research Service

Staub: W6743, W6744, W6745
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Germplasm Release

Published in HortScience 31:1243-1245:1996

Cucumber germplasm: isozyme genetic stocks W6743, W6744, W6745

Additional index words. Cucumis sativus, allozyme, genetic markers, seed purity assessment, plant variety protection

Jack E. Staub1, Vladimir Meglic2 and Linda K. Crubaugh3

Vegetable Crops Research, U. S. Department of Agriculture, Agricultural Research Service, Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706

Received for publication______. Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the USDA and does not imply its approval to the exclusion of other products that may be suitable.

1 Research Horticulturist and Professor.
2 Former Graduate Student.
3 Research Technician.


A series of cucumber (Cucumis sativus L. var. sativus) populations (W6743, W6744, W6745) containing alternate alleles (allozymes) for 20 enzyme coding loci were released in September 1995 by the Agricultural Research Service, United States Department of Agriculture. Lines within each population have been created through backcrossing and self-pollination to incorporate allozymes in three genetic backgrounds; European glasshouse, U.S. processing (pickling) and U.S. market (slicing) types. Within each population inbreds developed from single plant selections should be heterogeneous at specific isozyme or morphological loci, and homozygous at others. These genetic stocks could be used for genetic marker research (e.g., linkage assessment, genetic drift detection) or by breeding programs (the incorporation of unique allelic constructs into elite lines) as a tool for varietal purity assessment and plant variety protection.

Origin

Allelic variation was initially observed in a survey of elite, publicly-released, processing cucumber inbred and plant introduction accessions present in the U.S. cucumber collection (USDA Regional Plant Introduction Station, Ames IA) in adenylate kinase (AK), fructose diphosphatase (FDP), glucosephosphate isomerase (GPI), glutathione reductase (GR), glycerate dehydrogenase (G2DH), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), manosephosphate isomerase (MPI), peptidase with glycyl-leucine (PEP-GL), peptidase with leucyl-alanine (PEP-LA), peptidase with phenylalanyl-proline (PEP-PAP), peroxidase (PER), phosphoglucomutase (PGM), 6-phosphogluconate dehydrogenase (PGD), and shikimate dehydrogenase (SKDH) (Knerr et al., 1989, Knerr et al., 1994). Some allozymes of enzymes (e.g. G2DH, IDH, MPI, PGD, PEP-LA, SKDH) were not present in elite lines and were recovered from exotic germplasm (e.g., C. sativus var. hardwickii (R) Alef.; PI 183967 and PI 215589; Table 1). The inheritance of allozymes for these enzymes conforms to Mendelian expectations, and the linkage relationships among these allozymes and between allozymes and some economically important morphological loci have been characterized (Table 2; Knerr et al., 1989; Meglic, 1994).

Crosses were made among elite lines, and between elite lines and exotic germplasm to incorporate rare allozymes into adapted germplasm. Lines (>F4) were developed and used to determine the inheritance of the isozyme banding patterns resolvable in 15 enzyme systems using horizontal starch gel electrophoresis. These lines (5 to 10) were crossed to a European line (F3; European glasshouse type) derived from the intermating of three proprietary glasshouse lines from Numhems Zaden BV, De Ruiter Zonen BV, and Nickerson Zwaan, BV, Poinsett 76 (U.S. market type) and GY14 (U.S. processing type). These three lines were used as recurrent parents during backcrossing in which cross progeny heterozygous for isozyme loci were identified and used as parents. After four backcrosses, lines were self-pollinated for two generations and selected for alternate allozymes at each of 20 loci (Ak-2, Ak-3, Fdp-1, Fdp-2, Gpi-1, Gr-1, G2dh, Idh, Mdh- 1, Mdh-2, Mdh-3, Mpi-1, Mpi-2, Pep-gl, Pep-la, Pep- pap, Per, Pgm, Pgd-1 and Skdh), and uniformity in the three genetic backgrounds. This resulted in the production of 6 European glasshouse (W6743), 11 U.S. processing (W6744) and 8 U.S. market type (W6745) lines which were homozygous for alternate alleles [e.g. Ak- 2 (11) and (22)] at specific loci (Table 3).

Description

Although these BC4S2 lines are distinct and can be placed into broad classifications according to potential horticultural utility, they are not phenotypically uniform within a specific type classification (Table 3). Lines within a specific type vary in skin texture (smooth or warty) and mature fruit color (green to orange) and length:diameter ratio (L/D; measured in mm), depending on genetic background. Lines derived using European germplasm as recurrent parents tend to be smooth-skinned, relatively long and fine-spined. Lines derived from backcrossing to U.S. processing and market lines vary in spine color (black or white) and some segregate for skin texture attributes (i.e., warts and spine thickness) and exhibit a range in L/D (2.0 to 4.8). This lack of uniformity could be due to pleiotropic effects and/or linkages between allozymes and morphological traits (Meglic, 1994).

Availability

Limited seed of individual lots of these genetic stocks and composite lots of 6743-5 are available upon written request to J. E. Staub, USDA, ARS, Department of Horticulture, University of Wisconsin, Madison, WI 53706.

Literature cited

  • Clayton, J. W. and D. N. Tretiak. 1972. Amine-citrate buffers for pH control in starch gel electrophoresis. J. Fish. Res. Board Can. 29:11-69-1172.
  • Knerr, L.D., J.E. Staub, Holder D.J., and B.P. May. 1989. Genetic diversity in Cucumis sativus L. assessed by variation at 18 allozyme coding loci. Theor. Appl. Genet. 78: 119-128.
  • Knerr, L.D.and J.E. Staub. 1992. Inheritance and linkage relationships of isozyme loci in cucumber (Cucumis sativus L.). Theor. Appl. Genet. 84:217-224.
  • Knerr, L.D., V. Meglic, and J. E. Staub. 1994. A fourth malate dehydrogenase (MDH) locus in cucumber. HortScience 30:118-119.
  • Market, C. L. and L. Faulhaber. 1965. Lactate dehydrogenase isozyme patterns of fish. J. Exp. Zool. 159:319-332.
  • Meglic, V. 1994. Inheritance and linkage relationship between biochemical and morphological loci in cucumber (Cucumis sativus L.). PhD thesis, University of Wisconsin- Madison, USA.
  • Richmond, R.C. 1972. Enzyme variability in the Drosophila williston group. 3. Amounts of variability in the superspecies D. paulistorum. Genetics 70:87-112.
  • Ridgway, G. L., S. W. Sherburne, and R. D. Lewis. 1970. Polymorphism in the esterase of Atlantic herring. Trans. Amer. Fish. Soc. 99:147-151.
  • Selander, R. K., M. H. Smith, S. Y. Yang, W. E. Johnson, and J. B. Gentry. 1971. Biochemical polymorphism and systematics in the genus Peromyseus. I. Variation in the old-field mouse (Peromyseus polionotus). In: Studies in genetics, Univ. of Texas Publication, Austin.

Table 1

Sources of the less common allozymes in 15 cucumber (Cucumis sativus L.) enzymesz.

Locusy PI Source
Ak-2(2) 279469 Japan
279463 Japan
Ak-3(2) 169334 Turkey
255937 Netherlands
Fdp-1(2) 169383 Turkey
192940 Peoples Republic of China
Fdp-2(1) 137851 Iran
164952 Turkey
Gpi-1(1) 200815 Burma
422192 Hungary
Gr-1(1) 109275 Turkey
G2dh(1) 285606 Poland
Idh(1) 215589 India
183967 India
Mdh-1 (2) 171613 Turkey
209064 United States
Mdh-2 (1) 174164 Turkey
357835 Yugoslavia
419214 Hong Kong
Mdh-3 (2) 255236 Netherlands
267942 Japan
432854 People's Republic of China
Mpi-1(2)x 176954 Turkey
249562 Thailand
Pep-gl(1) 113334 Peoples Republic of China
212896 India
Pep-gl(2) 137851 Iran
212896 India
Pep-la(2) 169380 Turkey
354952 Denmark
Pep-pap(1) 163213 India
188749 Egypt
Per(2) 215589 India
Pgm(2) 171613 Turkey
177364 Iraq
Pgd-1(1) 169380 Turkey
222782 Turkey
Pgd-1(2) 188749 Egypt
289698 Australia
Skdh(1)x 302443 Taiwan
390952 Russia

z Sources are only given for the less common allele of a locus used based on previous studies by Knerr et al. (1989) and Knerr and Staub (1992). There is also a common allele in addition to each of those listed above.
y Enzyme loci designation where multiple loci of an enzyme is distinguished by hyphenated numerals and alleles are enclosed in parentheses ( ).
x Heterogeneous population containing alternate homozygous and heterozygous genotypes.


Table 2

Enzymes assayed using specific buffer systems which provided adequate resolution of isozyme loci observed in cucumber (Cucumis sativus L.).

Enzyme Abbreviation E.C.z
designation
Buffery
system
No. ofx
loci
Adenylate kinase AK 2.7.4.3 S-4 2
Fructose diphosphatase FDP 3.1.3.11 A 2
Glucosephosphate isomerase GPI 5.3.1.9 R 1
Glutathione reductase GR 1.6.4.2 S-4 1
Glycerate dehydrogenase G2DH 1.1.1.29 R 1
Isocitrate dehydrogenase IDH 1.1.1.42 S-4 1
Malate dehydrogenase MDH 1.1.1.37 S-4 3
Manosephosphate isomerase MPI 5.3.1.8 S-4 2
Peptidase with glycyl-leucine PEP-GL 3.4.13.11 A 2
Peptidase with leucyl-alanine PEP-LA 3.4.13.11 M 1
Peptidase with phenylalanyl-proline PEP-PAP 3.4.13.11 S-4 1
Peroxidase PER 1.11.1.7 A 1
Phosphoglucomutase PGM 5.4.2.2 R 1
6-phosphogluconate dehydrogenase PGD 1.1.1.43 S-4 2
Shikimate dehydrogenase SKDH 1.1.1.25 S-4 1

z Enzyme commission number.
y Buffers of Clayton and Tretiak (1972), Ridgway et al. (1970), and Selander et al. (1971), Markert and Faulhaber (1965) designated as C, R, and S or M, respectively.
x Loci designated by previous examination (Knerr and Staub, 1992) or during this survey using standard criteria and nomenclature (Richmond, 1972).


Table 3

Allozyme and morphological variation in genetic stocks of cucumber (Cucumis sativus L.).

  Allelic constitution of enzyme coding lociz Fruit Characteristics y
Identity Ak-2 Ak-3 Fdp
-1
Fdp
-2
Gpi
-1
Gr-1 G2dh Idh Mdh
-1
Mdh
-2
Mdh
-3
Mpi
-1
Mpi
-2
P-gl P-la P-
pap
Per Pgm Pgd
-1
Skdh Skin
texture
Skin
color
Spine
color
L:D
ratiox
European greenhouse type
6743A 12 22 22 22 22 11 22 12 22 22 11 12 11 22 22 22 11 12 22 22 Seg G-Y to Y-G W 3.8-6.0
6743B 12 22 22 22 22 11 22 12 12 22 11 12 11 12 22 22 11 12 22 22 Seg G-Y to Y-G W 3.8-6.0
6743D 12 12 12 11 22 11 22 22 11 22 11 12 12 11 12 22 11 11 12 22 Sm G-Y to Y W 4.0-5.5
6743E 22 22 22 22 22 22 11 22 11 22 11 22 11 22 22 22 11 11 22 22 Sm G-Y to Y W 3.8-5.6
6743I 22 22 22 22 22 22 22 22 11 22 11 11 11 12 22 22 11 11 22 11 Sm G to Y W 5.8-6.0
6743J 22 22 22 22 22 11 22 22 11 11 11 22 11 11 22 22 11 22 22 22 Seg Y W 3.5-3.8
U.S. processing type
6744C 12 12 22 11 22 11 22 12 11 22 11 22 22 12 22 22 22 12 22 22 W G to O W 2.8-3.0
6744F 22 12 12 11 22 11 22 22 22 22 11 22 22 22 22 22 11 11 22 22 W G-Y to Y W 3.2-4.0
6744G 22 12 11 22 11 11 22 22 12 22 12 22 22 22 12 22 11 11 22 12 W Y to Y-G W 3.0-4.5
6744H 22 12 12 11 22 11 22 22 12 22 22 22 22 22 22 22 11 11 22 11 W Y to Y-G W 2.8-3.5
6744I 11 22 22 22 12 11 22 22 11 22 22 22 22 12 22 11 11 11 22 22 W Y to Y-G W 2.5-3.3
6744K 11 22 22 11 11 11 22 22 11 22 12 22 22 22 22 11 11 11 22 22 Seg Y W 2.4-2.8
6744L 11 22 22 11 11 11 22 22 11 22 22 22 22 11 22 11 11 11 22 22 Seg Y-G to Y W 2.3-2.6
6744M 11 22 22 11 22 11 22 22 11 11 11 22 11 11 22 11 11 11 22 11 Seg G-Y to Y W 2.2-3.2
6744P 12 11 11 11 22 11 22 22 11 22 11 11 22 11 22 11 11 11 11 22 W Y-G to Y W 2.7-3.5
6744S 12 12 12 11 22 11 22 22 11 22 11 12 11 11 22 11 11 11 12 22 Seg O B 2.6-3.8
6744T 11 12 12 11 22 11 22 22 11 22 11 12 11 11 22 11 11 11 12 22 Seg O to YG B 2.0-3.5
U.S. market type
6745A 22 22 11 22 22 11 12 22 12 22 12 11 12 11 22 22 11 12 22 22 Seg O-Y to Y Seg 3.5-4.3
6745D 22 22 12 22 22 12 22 22 11 22 11 11 11 12 22 22 11 11 22 12 Seg O-Y to Y Seg 3.8-4.3
6745E 12 22 12 22 22 11 22 22 11 11 22 12 11 11 22 22 11 12 12 22 Seg G-Y to Y W 3.3-3.8
6745F 11 22 11 22 22 11 22 22 11 22 12 11 11 11 22 22 11 12 11 22 Seg G to Y W 3.0-3.8
6745G 11 22 11 22 22 11 22 22 11 22 22 11 11 11 22 22 11 11 11 22 Seg Y-G to Y W 3.8-4.5
6745H 12 22 12 22 22 11 22 22 11 12 12 12 11 11 22 22 11 12 12 22 W Y-G to Y W 3.8-4.8
6745J 12 12 22 11 22 11 22 12 11 22 22 22 11 22 22 22 22 12 22 12 Seg Y B 3.0-3.8
6745K 11 12 11 11 22 11 22 11 11 22 12 11 22 11 22 22 11 22 22 11 Seg O to Y B 3.0-4.3

z Allozymes that occur in highest frequency are given the mobility designation 100. All other alleles produce protein products with relative mobilities to allozyme 100 (mm) as follows:
Ak-2(1)-98, Ak-3(1)-98, Fdp-1(1)-96, Gpi-1(1)-98, Gr-1(1)-97, G2dh(1)-94, Idh(1)-94, Mdh-1(2)-101.5, Mdh-2(1)-98, Mdh-4(2)-102, Mpi-1(1)-96, Mp-2(2)-103, Pep-gl(1)-98, Pep-la(1)-98, Pep-pap(1)-95, Per(2)-105, Pgm(2)-102.5, Pgd-1(1)-98, Skdh(1)-98.
ySkin texture: Sm = smooth, W = warty, Seg = segregating; Skin color: G = green, Y = yellow, O = orange; Spine color: W = white, B = black, Seg = segregating;
xL:D = length:diameter ratio.



Last Modified: 8/3/2004