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Vegetable Improvement Newsletter

No. 20, February 1978

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


1. Resistance in Sweet Corn to Colletotrichum graminocolum

L.V. Gregory, L.J. Seybert, J.E. Ayers, and D.L. Garwood

Departments of Plant Pathology and Horticulture, The Pennsylvania State University, University Park, Pennsylvania 16802

The inbreds PaIa453 ae du wx and PaIa5125 ae du wx were observed to differ in field reaction to Colletotrichum graminocolum (Ces) G.N. Nils. which causes anthracnose. PaIa5125 ae du wx appeared to have less disease. No clearly defined susceptible-resistant reaction was observed in either inbred. Therefore, resistance was defined as the relative production of lesions from a given concentration of inoculum. The objectives of this research were 1) to determine if resistance could be distinguished on a basis of lesion production and if so 2) to determine the genetic basis of this resistance.

Experiments were conducted in the greenhouse and the field using both inbreds, the F1 hybrid and 4 segregating populations. Inoculum was prepared from 8 isolates of C. graminocolum grown on PDA for 10 days. A standard inoculum concentration of 4.0 x 105 spores/ml was applied with a pressurized sprayer. The number of lesions were recorded on the 5th leaf of each plant in the greenhouse 10 days after inoculation. In the field, the number of lesions on the 6th leaf were recorded 10 days after inoculation.

It appears that resistance determined on the basis of lesion production is present in the material tested. A lower number of lesions were produced on PaIa5125 ae du wx when compared to PaIa453 ae du wx in both greenhouse and field inoculations. The F1 responds similarly to PaIa5125 ae du wx in the field but appears intermediate in greenhouse inoculations. This may be due to fewer replications used in the greenhouse.

Much of the variation in these traits appears to be of genetic origin. Based on these data this resistance may be controlled by as few as 1 gene. From the field data, a quantitative phenotypic response and genotype may be assigned to each inbred as follows:

PaIa453 ae du wx – A1A1; 139.7 lesions; 20.7 lesions/dm2
PaIa5125 ae du wx – A2A2; 42.7 lesions; 6.9 lesions/dm2

From this the mean number of lesions and mean number of lesions per dm2 can be calculated for the segregating populations based on the proportion of genotypes present and assuming dominance:

 
Genotype frequencies
No. lesions- cal
No. lesions- obs
lesions/dm2- cal
lesions/dm2- obs
F2
0.25 (A1A1) + 0.75 (A2-)
67.0
84.1
12.4
15.6
P1 x F1
0.5 (A1A1) + 0.5 (A2-)
92.1
75.1
15.2
13.7
F1 x P1
0.5 (A1A1) + 0.5 (A2-)
92.1
70.9
15.2
12.7
F1 x P2
1.0 (A2-)
42.7
105.9
9.6
20.1

Other genes may influence lesion number in a quantitative manner of which only one was discernible in the material used in this study. It should be emphasized that plants exhibiting resistance as described here still sustain disease, but the reduction in inoculum efficiency compounded over several cycles of disease may be effective in preventing losses.


2. Procedure for Identification of Publicly Released Sweet Corn Inbreds

D.L. Garwood*

Department of Horticulture, The Pennsylvania State University, University Park, Pennsylvania 16802

Sweet corn inbreds released by breeders in the public sector will be designated by the two letter postal abbreviation for the state in which the release is made followed by a number. Sweet corn inbreds released prior to Jan. 1, 1977 will retain their previous identification; however, the two letter prefix may be added to sweet corn inbreds released before Jan. 1, 1977 that lacked prefix letters. To illustrate, sweet corn inbreds released by Illinois and Iowa, respectively, would be designated IL677 and IA5125.

This procedure was approved by the technical committee of USDA Regional Research Project NE-66. Members of the technical committee include a majority of sweet corn breeders in the United States. This procedure was adopted to prevent the use of the same prefix by more than one state as has occurred in the past and to eliminate uncertainty concerning the state of origin that has occurred when sweet corn inbreds have been released with only numerical identification.

*Chairman, NE-66 Technical Committee


3. Stabilization of Genetic Bean Root Rot Resistance by Combination with Cold Imbibition Tolerance and Root Vigor

M.J. Silbernagel

Research Plant Pathologist, USDA-ARS, Prosser, WA

Considerable research over the past thirty years has failed to control the losses due to Fusarium, Pythium, and Rhizoctonia root rots of beans. Recent genetic studies involving several sources of resistance have shown that measurable levels of disease tolerance are available; but no high level self sufficient sources of resistance are yet known. Even resistant varieties can be severely damaged under adverse conditions.

Many environmental factors are important in the severity of expression of root rot diseases, and most researchers will agree that any factors which inhibit, delay or interfere in any way with the optimal development of the host will increase the severity of root rot damage.

Some measure of disease abeyance is also possible through the use of chemicals such as seed and/or soil treatment fungicides and cultural practices such as subsoiling, rotation, incorporation of organic amendments, proper irrigation, and timing of planting.

Eventually I believe we will be able to reduce the effects of root rots to negligible levels by an integrated program incorporating the best available chemical and cultural controls with genetic resistance for specific situations.

I also believe that the low levels of root rot resistance in presently available germ plasm, might be stabilized by combining these factors with other genetically controlled factors which will help reduce the effects of environmental stresses that interfere with the optimal emergence, and normal rapid development of the host; factors such as resistance to cold imbibition injury and a strong vigorous root system. Neither of these factors in itself is capable of conferring any measurable level of root rot resistance. However, by minimizing or eliminating the stress effect on the host, hopefully the low levels of genetic root rot resistance will not “break down” as easily under conditions unfavorable to the host, but favorable to the pathogen.

A cold wet period immediately after planting can have a deleterious effect on a bean crop that even the return of ideal growing conditions will not remedy, and although genetic variability for cold imbibition tolerance has been identified; there have been suggestions that simply raising seed moisture content to 20% prior to planting will eliminate the need to breed for resistance to cold imbibition injury.

We tested this idea by planting a cold imbibition susceptible cultivar in cold soil vs warm soil at four seed moisture levels (8, 14, 20, and 26%) and measuring the effects on the green pod and dry seed yields. Seeds with 8% moisture, whether planted in cold or warm soils, produced weak seedlings and poor stands and yields, in comparison with seeds with higher moisture content. However, yields were poor in cold soils no matter how high the seed moisture content. Germination chamber studies substantiated field results. For example, optimal rate and uniformity of emergence, total emergence, seedling integrity and vigor were obtained with seeds having a moisture content of 14% germinated at 70 degrees Fahrenheit. Altering seed moisture content, lowering the temperature or decreasing oxygen availability during germination reduced emergence, seedling integrity and vigor. Therefore I am convinced of the need to breed for rapid uniform emergence in cold soils, as well as tolerance to oxygen stress during emergence due to wet soils, which is as detrimental as cold injury. We have been using a black seeded selection of PI 165426 as a source of resistance to cold wet imbibition injury; and in two cycles of selection have recovered segregants about midway between the resistant and the susceptible parents. Resistance seems to be recessive and quantitative.
           
The ability to grow vigorously under adverse early season conditions after emergence may be due to separate genetic factors, according to workers at the National Vegetable Research Center at Wellesbourne, England. So eventually we may also need to incorporate these factors, especially for areas with cool growing seasons such as England.
           
Breeding for root vigor is also slow and difficult because of the known association between seed size and root size. So in order to differentiate between lines with large roots, we use initial seed weights and seedling weights after 2 weeks in a root mist box to calculate rate of gain per day per unit of initial seed weight.  A large vigorous root system early in the season should not only allow better expression of the low levels of genetic root rot tolerance, but the more extensive root system should provide a greater number of nodulation sites and more extensive utilization of available water and nutrients. Greater water uptake availability may also be a contributing factor in tolerance to heat during bloom and pod fill.  We hope to have enough mist chamber selections in the field next year to see whether we can get correlation with root vigor under field conditions.
           
Our root rot breeding program consists of growing segregating materials for seed increase in a root rot infested field, where we make single plant selections primarily for plant and pod characteristics. In the greenhouse each line is screened separately in infested perlite for resistance to Fusarium, Pythium, and Rhizoctonia. Those lines showing tolerance to one or more pathogens are also given a cold-wet imbibition tolerance test, and a root vigor test in the mist chamber. In this way we are identifying root rot tolerant germ plasm which hopefully will be able to grow vigorously under adverse early season conditions. Survivors from all tests are increased in the greenhouse, hybridized to combine more resistance factors, then planted in the field again the following spring to complete the cycle.


4. Differentiation of Strains of Bean Common Mosaic Virus

E. Drijfhout1, M.J. Silbernagel2, and D.W. Burke2

1Research Plant Breeder, Institute for Horticultural Plant Breeding (IVT), Wageningen, The Netherlands

2Research Plant Pathologists, United States Department of Agriculture, Agricultural Research Service, Irrigated Agriculture Research and Extension Center, Prosser, Washington, 99350, USA.

The complete text of this work will be published shortly in the Netherlands Journal of Plant Pathology.

Seventeen described isolates of bean common mosaic virus (BCMV) and five previously unreported isolates were compared for pathogenicity and symptom expression on many bean cultivars (Phaseolus vulgaris L.). From these cultivars, a standard set of differentials were assigned to nine groups with different disease reactions. The twenty-two virus isolates comprised seven strain (pathotype) groups, three of which were divided into two subgroups each. To promote international standardization in BCMV research, recommendations are given concerning test conditions and procedures, criteria for strain differentiation, and maintenance of differential cultivars and virus strains.
           
Once it is established that a disease is caused by an isolate of BCMV, the test procedures and differential cultivars we propose can be used to determine if the isolate is a pure culture (or mixture), and whether it is similar to or different from previously reported strains. Internationally comparable results can best be obtained in the future if authors use the same procedures, conditions, differential cultivars and virus isolates used in the present study to compare against potential new virus strains, and/or new differential cultivars. To this end, the present authors propose to take responsibility for seed and/or strain distribution to researchers concerned with identification of strains of BCMV. Small seed samples will be sent on request for further propagation by the receiver in his greenhouse.
           
Seed samples of the differentials will also be deposited in the National Seed Storage Laboratory at Fort Collins, Colorado, USA, where they will be available for future researchers. The virus isolates (in seed) will be deposited in the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Maryland, 20852, USA, where they will also be available for future virus workers.

Table 1. Strains of bean common mosaic virus arranged according to pathogenic and symptomological groups identified in this report.

Strain Group
Isolate
Reference
Origin
I

Type

Westlandia (NL1)

Puerto Rico (PR9M)

Iran

Richard & Burkholder (1943)

van der Want (1954)

Alconero & Meiners ('72, '74)

Kaiser (unreported)

USA-Washington

Netherlands

Puerto Rico

Iran

II

NL7

R-220

S-74

PV-25

Drijfhout & Bos (1977)

Burke (unreported)

Drijfhout (unreported)

Goth (unreported)

Peru

USA-Washington

Netherlands

USA-New York

III
NL8
Drijfhout & Bos (1977)
Netherlands
IVa
Florida
Zaumeyer & Goth (1964)
USA-Florida
IVb

Idaho 123

Western

Colana (NL6)

Bailif

Dean &Wilson (1959)

Skotland & Burke (1961)

Hubbeling (1972)

Burke (unreported)

USA-Idaho

USA-Washington

Netherlands

USA-Washington

Va
NY-15
Richards & Burkholder (1943)
USA-New York
Vb

RM (NL2)

Imuna

van der Want (1954)

Hubbeling (1963)

Netherlands

''

VIa
Michelite (NL3)
Hubbeling (1963)
Netherlands
VIb
Jolanda (NL5)
Hubbeling (1972)
Netherlands
VII

Great Northern (NL4)

Mexican

Chile A-5

Hubbeling (1963)

Silbernagel (1969)

Alconero (unreported)

Netherlands

Mexico

Chile

Table 2. Bean host groups used for differentiation of BCMV strains.

Host Group
Cultivar
Origin
11

*Dubbele Witte

Sutter Pink

Stringless Green Refugee

Netherlands

USA

USA

2

*Redlands Greenleaf C

Puregold Wax

Imuna

Australia

USA

Germany

3

*Redlands Greenleaf B

Great Northern U.I. 123

Australia

USA

4

*Sanilac

Red Mexican U.I. 34

Michelite 62

USA

USA

USA

5

*Monroe

Great Northern U.I. 31

Red Mexican U.I. 35

USA

USA

USA

62
*Jubila
Germany
7

*Topcrop

Improved Tablegreen 40031

USA

USA

8

*Widusa

Black Turtle Soup

Netherlands

Mexico

9
*Amanda
Netherlands

1Cultivars of host groups 1 to 5 with presumed recessive inhibitor gene I.
2Cultivars of host groups 6 to 9 with presumed dominant inhibitor gene I.
*Preferred differential cultivar

Table 3. Host group x strain group interactions1

 
BCMV Strain Groups
Host Groups
I
II
III
IV
V
VI
VII
12
+3
+
+
+
+
+
+
2
-
+
-
+
+
+
+
3
-
-
-
+
-
+
+
4
-
-
+
-
+
+
-
5
-
-
-
-
-
-
+

1Greenhouse 16 hr daylight, mean temp 23-26 degrees Celsius (range 20-30 degrees)
2Cultivars of host groups 1 to 5 presumably carry the recessive alleles of the inhibitor gene I (Ali, 1950).
3- = Resistant; not recoverable by assay from new tip growth
+ = Sensitive or tolerant, recoverable by assay of new growth

Table 4. Host group x strain group interactions1

 
BCMV Strain Groups
Host Groups
I
II
III
IVa
IVb
Va
Vb
VIa
VIb
VII
62
-3
-
-
-
+
-
+
+
+
-
7
-
-
-
-
+
-
+
+
+
-
8
-
-
+
-
+
-
-
+
+
-
9
-
-
-
-
-
-
-
-
+
-

1Greenhouse 16 hr daylight, mean temp 23-26 degrees Celsius (range 20-30 degrees)
2Cultivars of host groups 6 to 9 presumably carry the dominant inhibitor gene I (Ali, 1950).
3- = Resistant at the temperatures mentioned. No systemic symptoms. Virus usually not recoverable by indexing from plant tips.
+ = Necrotic tip kill of some to all plants in the used temperature range. Virus usually not recoverable by indexing tips of symptomless plants (sensitive or variably sensitive).


5. Use of Bacterial Wilt Resistance in Hybrid Cucumbers

H.M. Munger

Department of Plant Breeding, Cornell University, Ithaca, N.Y. 14853

After the reporting of a single dominant gene (Bw) for bacterial wilt resistance in cucumber, R.E. Wilkinson of our Plant Pathology Department suggested adding the gene to some of our scab and mosaic resistant lines. He inoculated the segregating progenies, and dominance seemed to be complete as we progressed through 5 successive backcrosses to Tablegreen 65 and to SR551, slicing and pickling types respectively. The desirable features of the recurrent parents seemed to be restored in the final backcross progenies up to the point where homozygous Bw lines were obtained. Then the fruit was short, the plants were slow growing, flowering was very late. Discouraged by this, we shelved the material for several years.
           
Unusually severe incidence of bacterial wilt recently stimulated us to re-grow the resistant lines and try them in hybrid combinations. The heterozygous Bw hybrids are fully wilt resistant in all tests, and the undesirable features are much less apparent. In 1977 we included in a replicated test the hybrid Marketmore 70F x Tablegreen 65 Bw as a wilt resistant version of Meridian (Tablegreen 68 x Marketmore 70). The wilt resistant Meridian appeared to be comparable to Meridian in fruit length and only a little later in maturity. Its pattern of producing marketable fruits was comparable to Marketmore 70 in the first several pickings and far ahead of Tablegreen 72 (Table 1). These sketchy results along with similar additional observations suggest that hybrids of gynoecious x bacterial wilt resistant lines may be useful where wilt is a problem.
           
There may be some difficulty in maintaining the Bw parent lines. We almost lost the Tablegreen 65 by including it in our regular nurseries where it flowered too late to mature to fruit before frost. In the greenhouse it produced huge vines with very few female flowers. We hope to build up our present almost non-existent seed supply by chemical induction of females in the greenhouse and by very early planting for the field.

Table 1. Cumulative numbers of marketable fruits picked from 3 replicates in 1977.

 
1st* picking
2nd
3rd
4th
5th
6th
7th
8th
Tablegreen 72
1
1
6
24
54
76
108
131
Meridian
4
26
42
101
154
187
227
279
Meridian Bw
0
8
25
73
118
147
201
252
Marketmore 70
1
19
35
79
118
143
187
227

*Picked at 3 day intervals.


6. Breeding Lettuce for Resistance to Broad Bean Wilt Virus

R. Provvidenti, R.W. Robinson and J.W. Shail

Departments of Plant Pathology, and Seed and Vegetable Sciences, New York State Agricultural Experiment Station, Geneva, N.Y. 14456

Broad bean wilt virus (BBWV) causes mosaic and necrotic symptoms on lettuce that are often confused with lettuce mosaic virus (LMV). This virus is one of the reasons why the use of M.T.O. seed has not given adequate control of mosaic in New York lettuce fields. Losses from broad bean wilt virus were especially damaging in 1977, and BBWV was frequently recovered from lettuce plants with mosaic symptoms in commercial fields.
           
Ithaca, Minetto, and other lettuce cultivars grown in New York are very susceptible to BBWV. We found Lactuca virosa (PI 274375) to be a good source of resistance. However, it is not necessary to make this interspecific cross to obtain BBWV resistance, for we also found resistance in ‘Vanguard 75’ and in several other lettuce cultivars. All resistant cultivars and species were symptomless carriers, being easily infected but not developing symptoms.
           
Resistance to BBWV is a dominant trait. This is a useful attribute for the use of ‘Vanguard 75’ in a backcross program as a source of resistance to LMV and BBMV, since it permits the distinction between the true hybrid plants and the accidental selfs in each backcross. The recurrent susceptible parent, if used as the female in each cross, will produce BBWV susceptible progeny if selfed, whereas F1 plants will be resistant and subsequent backcrosses will segregate for BBWV resistance.


7. Lactuca Saligna: A Source of Cucumber Mosaic Virus Resistance for Lettuce

R. Provvidenti, R.W. Robinson and J.W. Shail

Departments of Plant Pathology, and Seed and Vegetable Sciences, New York State Agricultural Experiment Station, Geneva, N.Y. 14456

Over 500 plant introductions of Lactuca sativa were screened for resistance to cucumber mosaic virus (CMV), the most important virus found in a 3-year survey of lettuce fields in New York, but none was resistant. However, a good source of CMV resistance was found in L. saligna PI 261653.

L. saligna was crossed with several lettuce cultivars. Each F1 was resistant, indicating that CMV resistance is dominant. The L. saligna x L. sativa hybrids had reduced fertility, but seed production was adequate to permit using this interspecific cross to breed lettuce resistant to CMV.

L. saligna is also resistant to cabbage looper (1) and to downy mildew (2), making this species a valuable parent for breeding insect and disease resistant lettuce.

  1. Kishaba, A.N., T.W. Whitaker, P.V. Vail, and H.H. Toba. 1973. Differential oviposition of cabbage loopers on lettuce. J. Amer. Soc. Hort. Sci. 98:367-370.
  2. Netzer, D., D. Globerson, and J. Sacks. 1976. Lactuca saligna: a new source of resistance to downy mildew (Bremia lactucae Ref.). HortScience 11:612-613.

8. Interspecific Gene Transfer for Disease Resistance Between Chicory and Endive

R. Provvidenti, R.W. Robinson and J.W. Shail

Departments of Plant Pathology, and Seed and Vegetable Sciences, New York State Agricultural Experiment Station, Geneva, N.Y. 14456

Turnip mosaic virus is a serious disease of endive and escarole, often causing 100% losses in New York, New Jersey, and other areas. A good source of resistance to this destructive disease may be obtained from certain varieties of chicory.
           
Chicory (Cichorium intybus) is easy to cross with endive and escarole (C. endiva), and there is often a high incidence of natural interspecific hybrids under field conditions due to the self incompatibility of the chicory parent (1). We have taken advantage of this cross to transfer resistance to turnip mosaic virus from chicory to endive and escarole.
           
‘Catalogna’ (‘Radichetta’) chicory was used as the source of turnip mosaic resistance. An accession of wild chicory and the ‘Witloof’ cultivar were also resistant, but ‘San Pasqualle’ was susceptible. Resistance is dominant, since the F1 of ‘Catalogna’ chicory x ‘Full Heart’ escarole was resistant to turnip mosaic virus.
           
Reasonably good seed production was obtained from the interspecific hybrid in the field. A severe epiphytotic of aster yellows in the seed production field caused severe losses to lettuce and endive, but Catalogna chicory and its hybrid with ‘Full Heart’ escarole were symptomless. The possible role of chicory in breeding endive and escarole for resistance to aster yellows deserves attention.
           
The breeder should guard against transferring genes for disease susceptibility as well as disease resistance in this interspecific cross. This could easily be done inadvertently, since ‘Catalogna’ chicory is susceptible to powdery mildew, a disease that does not normally attack endive or escarole. Susceptibility to powdery mildew is dominant, since F1 of ‘Catalogna’ x ‘Full Heart’ was susceptible.

  1. Rick, C.M. 1953. Hybridization between chicory and endive. Proc. Amer. Soc. Hort. Sci. 61:459-466.

9. Effect of Plant Population and Seed Vigor on Cucumber Sex Expression

B.F. George

Heinz U.S.A, 13737 Middleton Pike, Bowling Green, Ohio 43402

Reports at the recent Pickling Cucumber Improvement Committee meeting indicated that selection of cucumber plants from very high population densities (flats) and from low vigor seeds should improve female stability of gynoecious inbreds. A greenhouse test was conducted this winter to determine variety response to these types of stress.
           
Vigor differentials were developed by pre-germinating seed for A (48 hrs.), B (24 hrs.), C (8 hrs.), and D (Ohrs or control) and then air drying for 24 hrs. prior to seeding. High populations were obtained by using 2 ¼” jiffy pots with 2 seeds per pot or 100 seeds per flat. Seeding was done on Oct. 2 following pre-germination treatments with 3 inbreds, SR551F (moderate gynoecious), H3216 (weak gynoecious) and Gy14A (strong gynoecious). The seed lots had been previously produced in inbred field cages and had been classified for sex types, as 93%, 90%, and 100% gynoecious respectively.

Sex expression was read on Jan. 16 for the first 5 nodes of each plant. The plants were placed in one of 3 classes, gynoecious (no male flowers) PF or monoecious, and androecious (no female flowers). Greenhouse temperature had been set at 55 degrees Fahrenheit night and 65 degrees Fahrenheit days with natural low light intensity for the period Oct.-Jan.

The results of this test (Table 1) shows that although 48 hrs. of pre-germination and then drying was a very severe stress, as indicated by the total % germination in the flats, it didn’t reduce the percentage of gynoecious plants compared to the control. In fact none of the pre-germination treatments had any major effect on shifting sex expression.

The variety response to the population stress was different, and as expected. SR551F which has been 100% gynoecious in field observation, but would break down in field cages with additional stress, produced more male flowers than did the Gy14A which has been very stable. The H3216 behaved as expected, as it is prone to produce PF’s and monoecious types under general field stress.

One might grow out the gynoecious plants of SR551F and Gy14A for seed and gain increased gynoecious stability; but growth of H3216 completely terminated due to its determinate nature. It appears that population stress alone is sufficient to alter sex expression. In fact, the lowest vigor but low plant population treatment (A) generally produced more gynoecious plants than did the control suggesting that the population stress was of more importance than was the pre-germination stress.

Table 1. Sex classification of plants based on first 5 nodes as affected by seed vigor. Bowling Green, OH 1978.

Variety-Treatmentz
Total Plants
% Gynoecious
% Monoecious
% Androecious
SR551F- A
24
79
21
0
B
80
63
33
4
C
83
79
17
4
D
88
67
27
6
H3216 A
36
11
69
20
B
97
0
69
31
C
95
4
83
13
D
97
3
74
23
Gy14A A
32
94
6
0
B
93
90
10
0
C
83
96
4
0
D
85
92
8
0

zTreatments were pre-germination for A=48 hrs, B=24 hrs, C=8 hrs. and D control. All were air dried for 24 hrs. before planting at the same time.


10. Breeding for Type and Brown Canker Resistance in Parsnip

D.W. Davis and F.L. Pfleger

Department of Horticultural Science, University of Minnesota, St. Paul, MN 55108

Serious outbreaks of brown canker (root canker) of parsnip as caused by the fungus Intersonilia perplexans have occurred in commercial fields in Minnesota and certain other production regions from time to time. In 1974 we began to search for solutions to the problem via fungicide and cultivar testing. Thirteen cultivars were examined in replicated trials in 1974; 17 in 1975 and 8 in 1976. Most cultivars were tested over at least 2 years under commercial practice on organic soil known to have produced cankered parsnips in earlier years.

At an October harvest each year unwashed roots selected for type and freedom from defects have been placed in storage under high-canker-induction conditions, i.e. 50-55 degrees Fahrenheit and about 98% relative humidity for several months, or until severe deterioration occurred. At this time apparently resistant roots are selected to produce a summer seed crop, followed by another root crop the second year. Currently we are working on techniques that will permit screening and cycling on an annual basis rather than on the biennial basis.

Seed from selected roots has been produced in either of 3 ways: 1) by isolation in field locations, 2) by self pollination in the greenhouse, and 3) by the use of a modified polycross in the field. Self pollination was accomplished by bagged files the first year; however, this past year we selfed manually. This was done by a rapid daily hand rubbing of each inflorescence with hand washing via an aseptic solution between plants. Seed set was poor to good, but nearly always sufficient to obtain adequate seed for field tests.

In the polycross, canker-free vernalized roots from known cultivars are planted in the field in a restricted design to give maximum exposure of each cultivar to all others and thus to encourage cross pollination. Seed produced from such blocks does seem to produce a high proportion of presumed crosses, based on root type.

Our best source of resistance is in ‘Avonresister’, although we also have selected from several other foreign and domestic cultivars. The program is directed toward minimal expenditure of effort, in that the parsnip is a minor crop in our area. However, we are encouraged by the degree of progress made thus far. We would like to hear from readers who have had experience in parsnip improvement.


11. Uncatalogued Vegetable Varieties Available for Trial in 1978

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 on source, the address is given only for the first.

  • Cabbage
    • 1242. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Large, round, smooth, blue-green head on a vigorous yellows and black rot resistant plant. Compare to Sanibel. 85 day type. Advanced trial. (R.O. Wilkins).
    • 1253. C.H. Cadregari. Medium sized, round, smooth, blue-green head on an upright, yellows and black rot resistant plant. Compare to Market Topper. 75 day market type. Advanced trial. (R.O. Wilkins).
    • 1254. C.H. Cadregari. Large, round, smooth, blue head on a vigorous yellows resistant plant that stands well. Compare to Roundup. 90 day type. To be released. (R.O. Wilkins).
    • 1256. C.H. Cadregari. Medium sized, round, smooth, bright green head on a vigorous yellows and black rot resistant plant. 80 day type. To be released. (R.O. Wilkins).
    • 6414. C.H. Cadregari. Medium-large sized, round, bright green head on a vigorous yellows resistant plant with high dry matter. Compare to Roundup or Titanic. 110 day type. Stands well without splitting. Advanced trial. (R.O. Wilkins).
  • Carrot
    • 6K14. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Long Nantes. Compare to Hipak. Advanced trial.
    • 6K16. C.H. Cadregari. Long market carrot, good color, early. Compare to Candy Pak. Advanced trial.
    • EN16. C.H. Cadregari. Long Nantes, early. Compare to Hipak. Advanced trial.
    • 1411AN. C.H. Cadregari. Long market carrot. Compare to Trophy. Advanced trial.
    • 14116K. C.H. Cadregari. Long market carrot. Compare to Candy Pak. Advanced trial.
    • 1411SN. C.H. Cadregari. Long semi-blunt Nantes. Compare to Hipak. Advanced trial.
    • 461-95. R.L. Engle, Dessert Seed Co., Inc., P.O. Box 9008, Brooks, Oregon 97305. Fresh market or slicing type. Uniform, deep orange color. Compare to Gold Pak. Advanced trial.
  • Cauliflower
    • MSU 812. S. Honma, Dept. of Horticulture, Michigan State Univ., East Lansing, Mich. 48824. Upright leaves, bred to withstand summer heat. Will mature 3-4 weeks earlier than Snowball M or Self-Blanche as a fall crop. Advanced trial.
    • MSU 817. S. Honma. Semi-upright leaves, summer type. Will mature 3-4 weeks earlier than Snowball or Self-Blanche in the fall. Advanced trial.
  • Cucumber
    • Castlex 2003. A.L. Castle, Inc., P.O. Box 279, Hollister, CA 95023. Hybrid pickling type. Gynoecious, white spine. Medium-dark green, cylindrical fruit. Intermediate length. Tolerant to scab, mosaic, anthracnose, angular leaf spot, downy and powdery mildew. Advanced trial. (Fred Angell).
    • Castlex 2004. A.L. Castle, Inc. Gynoecious, pickle. White spine, medium-dark green fruit. Uniform, well shaped. Intermediate-long fruit. Tolerant to scab, mosaic, anthracnose, downy and powdery mildew. Advanced trial. (Fred Angell).
    • C58H. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. SMR, early high yielding pickle. Compare to Compass. Preliminary trial. (R. Dumlao).
    • G4U4. C.H. Cadregari. SMR, early and productive, uniform color gene, slicing cucumber. Compare to Victory. Advanced trial. (R. Dumlao).
    • GDR3. C.H. Cadregari. SMR, tolerant to mildews, mid-early, uniform color gene, slicing cucumber. Compare to Pacer. Advanced trial. (R. Dumlao).
    • HSMR. C.H. Cadregari. SMR, some field tolerance to mildews, semi-compact vines with the uniform color gene slicing cucumber. Compare to Pot Luck/Park’s Whopper. Advanced trial. (R. Dumlao).
  • Egg Plant
    • Exp. BC. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Long oriental type, very dark color with green calyx. Compare to Ichiban. Advanced trial. (R. Dumlao).
    • Exp. RB. C.H. Cadregari. Improved Classic type with good shipping quality potentials. Compare to Classic. To be released. (R. Dumlao).
  • Muskmelon
    • Castlex 5003. A.L. Castle, Inc., P.O. Box 279, Hollister, CA 95023. Hybrid, early, firm flesh, small-medium cavity. Heavy net, very slight suture. Preliminary trial. (Fred Angell).
    • G25B. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Fusarium tolerance, quality. Compare to Gold Star. Advanced trial. (T. Superak).
    • G25VB. C.H. Cadregari. Fusarium tolerance, large. Compare to Saticoy. Advanced trial. (T. Superak).
    • IPC. C.H. Cadregari. Fusarium tolerance, powdery mildew-1 resistance, high quality. Compare to Gold Star. Advanced trial. (T. Superak).
    • 8CN1. T.C. Torrey, W. Atlee Burpee Co., 335 S. Briggs Rd., Santa Paula, CA 93060. Early, small, well netted, mildew resistant. Continuous fruit set. Compare to Early Dawn. Advanced trial.
  • Onion
    • 180-Ru. R.L. Engle, Dessert Seed Co., Inc., P.O. Box 9008, Brooks, Oregon 97350. Hybrid Southport Red Globe. Uniform size with a deep red color. Compare to Southport Red Globe or Ruby. Preliminary trial.
    • 1010-710. R.L. Engle. Early yellow Sweet Spanish type. Large onions, high yields. Compare to Golden Beauty. Advanced trial.
    • 5537. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Mid-season, storage type. Compare to Spartan Banner. Advanced trial. (T. Superak).
  • Pepper
    • Exp. RCEC. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Sweet, productive, TMVR cherry type. Compare to Large Red Cherry. Advanced trial. (R. Dumlao).
  • Radish
    • Fancy Red. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Resistance to Fusarium yellows, black root (Caphanomyces raphani), and root scurf (Rhizoctonia solani). Compare to Red Prince. Varietal protection patent has been applied for. To be released. (H.S. Humaydan).
  • Snap Bean
    • ARS-5BP-7. M.J. Silbernagel, ARS-USDA Irrig. Agr. Res. & Ext. Center, Prosser, Washington 99350.  Resistant to heat during bloom, also resistant to curly top virus and bean common mosaic virus. Compare to BBL-274. Upright bush, concentrated maturity, very high yield. Early, white seed, pods green, long, large sieve, good Blue Lake flavor and texture. To be released.
    • ARS-6BP-5. M.J. Silbernagel. Resistant to curly top virus and bean common mosaic virus. Compare to Slenderett, Wondergreen. White seed, strong upright bush, concentrated maturity, adapted to mechanical harvest, pods smooth, green, straight and round in cross section, suitable for high density culture, good processed quality. To be released.
    • ARS-6BP-6. M.J. Silbernagel. Resistant to curly top virus, bean common mosaic virus and some chlorotic strains of bean yellow mosaic virus. Compare to OSU-190, Bush Blue Lake. Weak bush, upright habit, concentrated maturity, adapted to mechanical harvest and high density culture. White seed. Pods green, 5” long, slightly creasebacked. Typical Blue Lake bumpiness. Good processed flavor and texture. To be released.
    • 75-1498. S. Honma, Dept. of Horticulture, Michigan State Univ., East Lansing, Mich. 48824. Wax romano pod, bush habit, same as Green Ruler except wax pod color. Seed greenhouse grown. To be released.
  • Squash
    • Castleblack. A.L. Castle, Inc., P.O. Box 279, Hollister, CA 95023. Hybrid, black-green zucchini, cylindrical smooth fruit with uniform solid black-green color. Productive. To be released. (A. Lee).
    • Castlegold. A.L. Castle, Inc. Hybrid, yellow straightneck. Early, attractive, uniform, glossy, lemon yellow, smooth fruit. To be released. (A. Lee).
    • Castlegrey. A.L. Castle, Inc. Early, hybrid grey zucchini type. Medium single-stem plants. Cylindrical to slightly tapered fruit. To be released. (A. Lee).
    • Castle Verde. A.L. Castle, Inc. Hybrid, dark green zucchini. Early, cylindrical, uniform, smooth, glossy fruit. For market and processing. To be released. (A. Lee).
    • Castlex 4004. A.L. Castle, Inc. Hybrid, yellow crookneck. Early. Fruits are bright yellow, smooth with slender, modified crook. Productive. Advanced trial. (A. Lee).
    • 8PC. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. Yellow straightneck. Compare to Seneca Prolific. Advanced trial. (T. Superak).
    • WZ. C.H. Cadregari. White zucchini. Compare to White Bush Vegetable Marrow. Advanced trial. (T. Superak).
    • Mixta Gold. A.M. Rhodes, 206 Vegetable Crops Bldg., Univ. of Illinois, Urbana, Illinois 61801. Fruit mostly golden in color with underside green. Compare to Green Striped Cushaw. Preliminary trial.
    • 8S1. T.C. Torrey, W. Atlee Burpee Co., 335 S. Briggs Rd., Santa Paula, CA 93060. Short vine F1 hybrid Butternut. Concentrated crown set. Extra deep flesh color. Compare to Waltham Butternut. Preliminary trial.
  • Sweet Corn
    • VH701. E.A. Kerr, Hort. Exp. Sta., Box 587, Simcoe, Ont., Canada, N3Y 4N5. Early midseason, good appearance and eating quality, easy snap. Compare to Sundance. To be released.
    • Golden Gleam. C.H. Cadregari, Joseph Harris Co., Inc., Rochester, N.Y. 14624. 90 days. Field tolerance to MDM, tall, sturdy plant, dark green, excellent husk appearance, white silk, good quality. Compare to Golden Queen. Released. (Bruce G. Wilkins).
    • Quick Silver. C.H. Cadregari. 79 days. Sturdy plant, high quality, straight rows, good husk appearance, machine adaptability. Compare to midseason whites. Released. (Bruce G. Wilkins).
    • Sweet Sal. C.H. Cadregari. 86 days. Improved seedling vigor, high quality, good uniformity, attractive husk, tender. Compare to Sweet Sue. Released. (Bruce G. Wilkins).
    • H445. C.H. Cadregari. 88 days. Field tolerance to MDM, sturdy plant, good quality, tight attractive husk, bright yellow kernels. Compare to Golden Queen. Advanced trial. (Bruce G. Wilkins).
    • H 121666. C.H. Cadregari. 75 days. Good field tolerance to MDM, Bellringer type ear, good shape, attractive in husk. Compare to Bellringer. Preliminary trial. (Bruce G. Wilkins).
    • H 12266. C.H. Cadregari. 77 days. Good field tolerance to MDM, Bellringer type ear, good shape, attractive in husk, good yielder. Compare to Bellringer. Preliminary trial. (Bruce G. Wilkins).
    • WH1235. C.H. Cadregari. 94 days. Improved seedling vigor, excellent quality, tender, very attractive husk, bright white kernels. Compare to Silver Queen. Preliminary trial. (Bruce G. Wilkins).
  • Tomato
    • Castlex 1015. A.L. Castle, Inc., P.O. Box 279, Hollister, CA 95023. Hybrid, cherry type. Dwarf vine. Dark green rugose foliage. Uniform size and shape, good flavor. Jointless. F resistant. To be released. (F. Angell).
    • Castlex 1016. A.L. Castle, Inc. Hybrid, market type. Medium early. Medium-large fruit, green shoulder, smooth, jointless. VF. Advanced trial. (F. Angell).
    • Castlex 1018. A.L. Castle, Inc. Hybrid market type. Medium early. Large, smooth, firm fruit. Uniform ripening. Medium vine. VF. Advanced trial. (F. Angell).
    • Castlex 1025. A.L. Castle, Inc. Hybrid, market type. Early. Medium-large fruit, smooth, firm, green shoulder. Productive. VF 1&2, Alternaria stem canker resistant. Advanced trial. (F. Angell).
    • Castlex 1501. A.L. Castle, Inc. Hybrid processing tomato. Early, plum-blocky, firm fruit, uniform ripening. Crack resistant. Productive VF. Advanced trial. (A. Lee).
    • Castlehy 101. A.L. Castle, Inc. Hybrid market type. Early. Medium-large fruit, firm, green shoulder. Suitable for bush and stake culture. High yield potential. VF. Released. (F. Angell).
    • Ont 738. E.A. Kerr, Hort. Exp. Sta., Box 587, Simcoe, Ont., Canada, N3Y 4N5. V.F. ug ogc sp early midseason, very firm, heart-shaped, hand-pick. Compare to C 28. Processing for product.  Attractive whole pack but must be cored. To be released.
    • Ont 771. E.A. Kerr. F u sp early, crack resistant, smooth, oblate, handpick. Compare to Springset. Slightly earlier, firmer and more crack resistant than Springset. Fresh market, juice, and product. Advanced trial.
    • Ont 778. E.A. Kerr. V.F. u ogc sp midseason, firm, smooth, oblate, handpick. Compare to H 1350. Promising for fresh market and product. Advanced trial.
    • Ont 7511. E.A. Kerr. VF ug ogc sp midseason, firm, crack resistant, smooth, deep round, hand-pick. Compare to H 1350. Good cold germination, fresh market and product. Advanced trial.
    • Ont 7714. E.A. Kerr. F u sp j ogc early, coreless, small, round, machine harvest. Compare to H 1706. Whole pack or juice. Advanced trial.
    • Auburn 76-FMN. Walter H. Greenleaf, Horticulture Dept., Auburn Univ., Auburn, Alabama 36830. High quality (good flavor), high yield, indeterminate, resistant of Fu (race 1), TMV and root knot. Compare to Homestead 24, Walter. AU 76 has genes I, Tm2a and Mi. Released in January 1977.
    • 8T1. T.C. Torrey, W. Atlee Burpee Co., 335 S. Briggs Rd., Santa Paula, CA 93060. Early, indeterminate VF resistant. Compare to Big Early – Jet Star. Advanced trial.
    • 8T2. T.C. Torrey. Extra large home garden Beefsteak type VF. Compare to Beefmaster- Bragger. Advanced trial.
    • Royal Red Cherry. A.H. Millett, Dept. of Vegetable Crops, University of California, Davis, CA 95616. Deep red fruit, resistance to fusarium (race 1), verticillium wilt, tobacco mosaic virus and alternaria stem canker. Compare to Large Red Cherry. To be released. (Paul G. Smith).
    • Short Red Cherry. A.H. Millett. Brachytic indeterminate plant. 13” shorter than Large Red Cherry. Fruit slightly smaller and more acid. Resistant to Fusarium (race 1), verticillium, tobacco mosaic, alternaria stem canker and root knot nematode. To be released. (Paul G. Smith)

12. Experimental Stocks Available

We have 25-30 sweet corn hybrids (established and experimental) which we would like to sample for short row trials throughout MDM problem areas. Two 40 kernels samples of each variety would be sent to allow two replications. Those wishing to participate in this MDM trial should direct replies to:

Bruce G. Wilkins
Joseph Harris Co., Inc.
Rochester, N.Y. 14624

 

I have some eggplant material that I collected in Africa (West) that is related to S. melongena and has mite and verticillium tolerance. It is interesting material to work with and I would be glad to share it with anybody interested.

Bernard L. Pollack
Extension Service, College of Agriculture
Rutgers- The State University
New Brunswick, N.J. 08903

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Page citation: Wehner, T.C., Cucurbit Genetics Cooperative;
Created by T.C. Wehner and T. Ng, 1 June 2005; design by C.T. Glenn;
send questions to T.C. Wehner; last revised on 5 May, 2006