Skip to main content
ARS Home » Southeast Area » Charleston, South Carolina » Vegetable Research » Docs » CGC » Vegetable Improvement Newsletter No. 17, February 1975
Vegetable Improvement Newsletter No. 17, February 1975
headline bar

Compiled by H.M. Munger, Cornell University, Ithaca, New York

1. Sungold or CW 198 Wax Bean

M.H. Dickson

New York State Agricultural Experiment Station, Geneva, N.Y.

Sungold was released to the trade as CW 198 in February 1973. Sungold has been extensively tested in various parts of the country and has shown good general adaptation. The color is generally a bright, fairly deep yellow when canned and the canned product is uniform in size and color. Color has been good in all parts of the country where Sungold has been tested. Maturity is almost a day later than Earliwax. In extensive trials it has yielded competitively. The bush is upright and easy to pick. Seed of Sungold is available from various seedsmen for small trials and for limited commercial testing.

2. Release of Three Cytosterile Broccoli Inbreds and Maintainers

M.H. Dickson

New York State Agricultural Experiment Station, Geneva, N.Y.

Three cytosterile sterile inbreds, G1005, G1012, and G1043, and their maintainers are being released as female parents for production of hybrid broccoli. These have been developed from the cross B. nigra (mustard) x B. oleracea made by O. Pearson. The cytosteriles are female fertile and set seed quite well in the field when open pollinated, and are sib fertile with their maintainers. The maintainers are self fertile and set seed with brush pollination.

3. The Inheritance of Clustery Pistillate Flowers in Cucumbers

P.S. Thaxton and L.M. Pike

Texas A&M University, College Station, Texas

Clustering of flowers was observed in several gynoecious lines and all hermaphroditic lines of cucumbers. A genetic study was made to study the clustering characteristic in three cucumber lines. They were TAMU 950, a hermaphroditic line; MSU 3091, a clustering gynoecious line and Gy-3, a non-clustering gynoecious line.

Appropriate crosses were made and clustering was observed in the expected ratio in the F1, F2, and BC1 which had MSU 3091-1 as a parent (Table 1). Clustering was always observed in the hermaphrodites.

Data showed that clustering of pistillate flowers was conditioned by a single dominant gene. The clustering in hermaphrodites was closely linked with the hermaphroditic character and masked the gene effect for clustering or non-clustering in the pistillate flowering types.

Table 1. The inheritance of clustery pistillate flowers in cucumbers.

 
Test for a single dominant gene
 
Clustering flowers (C_)
Non-clustering flowers (cc)
Pedigree
Total Observed
Ha
Ob
Ec
O
E
X2
MSU 3091-1
10
0
10
10
0
0
TAMU 950
10
10
0
0
0
0
Gy-3
10
0
0
0
10
10
(950 x 3091-1)F1
17
0
17
17
0
0
(950 x Gy-3)F1
13
0
0
0
13
13
(3091-1 x Gy-3)F1
15
0
15
15
0
0
(950 x 3091-1)950
134
65
51
35
18
34d
(950 x 3091-1)3091-1
93
0
93
93
0
0
(950 x 3091-1)F2
73
35
27
28
11
10
.70-.80
(950 x Gy-3)950
55
18
0
0
37
37
(950 x Gy-3) Gy-3
8
0
0
0
8
8
(950 x Gy-3)F2
4
0
0
0
4
4
(Gy-3 x 3091-1)Gy-3
20
0
9
10
11
10
.50-.70
(Gy-3 x 3091-1)3091-1
55
0
40
41
15
14
.60-.70
(Gy-3 x 3091-1)F2
123
0
123
123
0
0

a hermaphrodites
b observed
c expected
d masking of pistillate flowers by the hermaphroditic character made it impossible to separate clusters due to dominant gene or hermaphroditic linkage.

4. Scab Resistance in Relation to Fruit Length in Slicing Cucumbers

H.M. Munger and R.E. Wilkinson

Cornell University, Ithaca, New York

In several cases where the single dominant gene for scab resistance has been backcrossed into slicing cucumber varieties, the resulting resistant lines have had shorter fruit than their recurrent parents. This happened in the North Carolina program that produced Ashe and Fletcher by adding resistance to Ashley and Stono respectively. We added scab resistance to Marketer at Cornell and after 9 backcrosses the resistant progenies were clearly shorter than either sister susceptible progenies or the recurrent parent. We also started with Ashe and made 5 additional backcrosses to Ashley, but the result was the same.

Fortunately less difficulty has been encountered with mosaic resistant slicers. Marketmore 70 and Tablegreen 65 are as long as their scab susceptible counterparts. In the latter case, however, about 25 homozygous resistant lines were evaluated and only one, which seemed to have fruit length comparable to the original Tablegreen, was multiplied as Tablegreen 65. Another line which had longer fruit than Tablegreen but was later and less productive was named Tablegreen 66 and released as germplasm.

Tablegreen 66 was used as the parent for adding scab resistance to Poinsett. After 6 backcrosses, heterozygous resistant plants were self pollinated and the next generation, the F2of the 6th backcross, was grown and selfed without testing for resistance. In this way, 3 pairs of homozygous resistant and susceptible progenies were obtained from the same heterozygous resistant plants. These were grown in 2 replicates in 1974 and the length and diameter of the fruits were measured. The length:diameter ratios in Table 1 were calculated only for fruits 15-18 cm long.

Table 1. Fruit shape of scab resistant and scab susceptible lines derived from 6 backcrosses to Poinsett cucumber.

  
Length + diameter
Scab reaction of progenyProgeny from BC6 F2 row
Rep. 1
Rep. 2
Mean
Number
Resistant
72-1015
3.96
4.05
4.01
86
Susceptible
"
3.73
3.57
3.66
47
Resistant
72-1016
3.99
3.98
3.99
100
Susceptible
"
3.80
3.52
3.73
55
Resistant
72-1018
3.79
3.81
3.80
64
Susceptible
"
3.73
3.67
3.71
56
Susceptible
Poinsett
3.90
-
17

For the first time in a backcross program, the scab resistant progenies have consistently longer fruits than their susceptible counterparts. The fruit of Tablegreen 66 was so much longer than that of comparable resistant progenies that it appeared that a linkage between resistance and short fruit might have been broken. That hypothesis is supported by the evidence that when Tablegreen 66 is the source of resistance, scab resistance is associated with longer rather than with shorter fruit.

5. Texas Onion Breeding

L.M. Pike and P.B. DeMille

Texas A&M University, College Station, Texas

Onion production in the state of Texas is a large industry comprising 26,000 harvested acres in 1973 for a total value of more than 66 million dollars (1). Problems associated with producing high quality onions economically for fresh and processed markets both domestic and foreign have put major emphasis on the onion breeding program at Texas A&M University.

Recently the South Texas Onion Committee awarded a grant to the Texas Agriculture Experiment Station for breeding onions with the proposed following objectives:

  1. Varieties be developed that have market acceptance in both the domestic and export markets in both the fresh and processed forms.
  2. A series of new varieties be developed that are adapted to a broader photoperiod to permit growing, harvesting, and marketing over a longer time period.
  3. Varieties for exporting, domestic markets and processing be interlocked to extent possible.
  4. Varieties be developed suitable for storage to regulate rate of flow to market for more orderly marketing.
  5. Varieties be developed with disease resistance and tolerance under South Texas climate conditions.
  6. Varieties be developed that are adaptable for machine harvesting and handling.

Literature Cited

1. Texas Vegetable Statistics, Texas Crop and Livestock Reporting Service, Bul. 106, March, 1974.

6. Further Results in Testing for Onion Maggot Resistance

H.M. Munger and R.F. Plage

Department of Plant Breeding, Cornell University, Ithaca, New York

Last year we reported that on the basis of a 1973 test there seemed to be some maggot resistance in certain onion varieties (VIN 16:4-6). A reduced list of PI's was tested in 1974 with 6 replicates to improve reliability. The same 3 entries had the least maggot damage in both years. Two of these are non-bulbing onions- PI 274254 (A. fistulosum from Japan) and PI 171481B (A. sp. from Turkey), but the third is a bulbing onion, PI 344251 from Turkey. PI 344251 had 63% survival on July 11, 1974 vs. 76 and 71% for the non-bulbing PI's and 6, 17, and 16% for 3 different lots of Downing Yellow Globe. It is mostly yellow with some red bulbs, and has reasonably good size and keeping quality.

'Makoi' from Hungary had been among the best 20 entries in the first screening and had somewhat less damage than DYG in 1973. 'Ljaskowski' from Sluis and Groot in Holland gave results similar to 'Makoi' when first tried in 1973. Both had distinctly less damage than DYG in 1974, although more than 344251.

The table shows lower initial stands for some of the better entries, only older seed being available for those. In 1973 there were indications that poor stands had lower percentage loss from maggots. Therefore in 1974, 3 reps were thinned to 2 inches spacing and 3 reps to 1 inch spacing on May 24. The average percentage loss from maggots was identical for the 2 spacings. Consequently, it seems unlikely that the lower maggot damage of certain entries is an artifact of thin stands.

 
1973 - 2 reps
1974 - 6 reps
 
Stand May 29
% Surv. July 3
% w/Maggots
Stand May 25
% Surv. July 11
% w/ Maggots
DYG- Trapp
92
24
37
202
16
49
DYG- Harris
100
13
63
218
6
59
Trapp's No. 6
88
58
28
205
17
53
PI 171481B A. sp.
82
83
2
190
76
18
PI 274254 A. fist.
103
67
15
211
71
25
PI 344251
33
85
6
84
63
17
Ljaskowski
59
44
32
96
52
13
Makoi
80
45
29
126
43
21

Trapp's No. 6 was included because of some evidence that it was less damaged than DYG by maggots in Michigan. This idea was supported by the 1973 results by decidedly not in the more reliable 1974 test.

7. Effect of Round vs. Wrinkled Seed on Protein Content of Field Peas

A.E. Slinkard

Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N OWO, Canada

The objective of this study was to determine the effect of seed shape (round vs. wrinkled) on protein content of field peas. This study was prompted by the observation that most of the high protein lines from the World Pea Collection were wrinkle-seeded. Accordingly, crosses were made between several high protein, wrinkle-seeded pea varieties and low protein, round-seeded pea varieties. Individual F2 plants that were segregating for round vs. wrinkled seed in the field in 1973 were selected and the wrinkled seed separated from the round seed. In 1974 paired comparisons were made of round vs. wrinkled F3 plant rows derived from the same F2 plant. Results indicate that the wrinkled-seeded member of the pair was consistently higher in protein. Studies are currently underway to determine possible causes for this. It is not thought to be due to the genetic difference, as such.

8. Identifying Extra Sweet Kernels of Sweet Corn

Stuart N. Smith

Sweet Corn Genetic Service, 808 E. Lincoln Way, Ames, Iowa 50010

We have been using an interesting system of identifying extra sweet kernels on segregating ears this winter and it seems to be quite effective. This is in connection with a project to determine the contributions of the F11 gene to pericarp texture in crosses between sugary and floury types. The sugary kernels on segregating ears which also carry the F11 gene tend to remain round at the crown and undimpled longer than the sugary kernels on a dent or flint base. This is clearly visible only at a moisture of about 40 to 45%. At this stage the well rounded kernels are marked on the crown with a black weatherproof pen and in this way are readily visible when the ears are dried. After the ears get into the 30% range and especially after they are dried, it is very hard to tell one kernel type from the others unless so marked.

9. Multiple Disease Resistance with a Linked Seedling Marker Gene for the Tomato

R.W. Robinson and R. Provvidenti

New York State Agricultural Experiment Station, Geneva, New York

Hoffman's anthocyaninless gene (ah) is an excellent seedling marker for tobacco mosaic virus resistance in the tomato. It can be easily classified in the early seedling stage; has no known detrimental effect on vigor, fertility, or other factor of economic importance; and is closely linked to the Tm-2 locus on chromosome 9.

Stocks homozygous for ah and Tm-2a, synthesized from F2 crossovers, were crossed with Nova. Derivatives of this cross which are homozygous for ah, Tm-2a, Ve, 1, and Ph were selected, and are being offered to breeders as germplasm. They are resistant to four diseases -TMV, Verticillium, Fusarium, and late blight.

By selecting seedlings with green stems (ah) in segregating generations from crosses with these stocks, breeders can increase the proportion of plants homozygous for TMV resistance from 25% to over 90%. These stocks may also be useful because they eliminate undesirable genes linked to Tm-2a that are distal to the crossing over with ah.

The multiple disease resistance of these stocks and the dominance of the resistance genes would be beneficial for producing F1 hybrid cultivars. The other parent of the hybrid, however, should have the Tm-2 or Tm-2a allele in order to prevent necrosis. The ah gene can be used as a marker to detect accidental selfs if one of these stocks is used as the maternal parent of an F1 hybrid.

10. Uncatalogued Vegetable Varieties

This list is aimed at facilitating the exchange of information about potential new varieties, or new varieties which have not yet appeared in catalogues. Persons conducting vegetable variety trials who wish seed of items on this list should request samples from the sources indicated.

It is the responsibility of the person sending out seed to specify that it is for trial only, or any other restriction he may want to place on its use.

Crops are listed alphabetically. For each entry the following information is given: Designation, source of trial samples, outstanding characteristics, variety suggested for comparison (not given separately if mentioned in description), status of variety (preliminary trial, advanced trial, to be released, or released) and contributor of information if different from source of trial samples. Where several samples are listed consecutively from one source, the address is given only for the first.

11. Stocks Desired