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Vegetable Improvement Newsletter No. 7, February 1965
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Compiled by H.M. Munger, Cornell University, Ithaca, New York

1. Release of Md. 63-84, a Bush Blue Lake Breeding Line

Robert J. Snyder

Department of Horticulture, University of Maryland

The Maryland Station has released Md. 63-84 as a bush Blue Lake breeding line. It has been inbred 7 generations following a cross of Seminole x Asgrow B.L. 92. In 1964, it was evaluated as a processing variety at 14 different locations throughout the United States. Although it has undesirable characteristics which rule it out as a new processing variety, it does have desirable characteristics sought for in a bush Blue Lake. A description is as follows:

Plant Habit - stems rather weak which bend over when pods become heavy; leaves small in comparison with other bush Blue Lake types; plant height 17"; pods borne high, scattered, and produced on extended cluster bearing spurs. The bush habit has been rated fair to good although at several locations it did not appear to be adaptable to mechanical harvesting; concentration of pod set is good.

Fresh Pod Type - pod length short (4"); shape is round, unusually straight, plump, and smooth (no pubescence or bumps); internal and external color dark green. Pods are attractive in appearance.

Processed Pods - color, flavor, and firmness are equivalent to pole Blue Lake; seeds at all stages are very small and the locular cavity remains small so that the fleshy tissue remains succulent and intact for an unusually long period of time; although fiber content is higher than in most bush varieties, satisfactory levels of fiber are maintained through the stage of prime harvest.

Yield - equal to Asgrow Bush Blue Lake XP 240, at all locations where yield records were taken.

Dry Seeds - white, very small, and easily threshed from pods.

2. Inheritance of Male Sterility in Table Beets, Beta vulgaris L.

F.A. Bliss and W.H. Gabelman

Department of Horticulture, University of Wisconsin

A study of inheritance of male sterility was made in families derived from cross pollinations of table beet cultivars with sugar beet material known to contain cytoplasmic-genic factors conditioning male sterility. Progenies of appropriate matings suggest that phenotypically stable male sterility results from an interaction of two recessive genes with S cytoplasm. The completely dominant allele of the gene (X) restores male fertility and the dominant allele of a second gene (Z), which is independent of an hypostatic to (X) restores partial male fertility to plants having S cytoplasm. Plants containing N cytoplasm appeared to be male fertile regardless of the particular alleles of the genes X and Z which were present.

3. Bees in Pollination Cages

W.C. Barnes

Clemson University Truck Experiment Station

The use of cages with bees as pollinators has become a necessity in many breeding and seed maintenance programs. Many bees are lost and the colonies become weakened when used in these cages. It was found in clover breeding at Clemson that there was no cross pollination with plants on the outside when an opening was made in both ends of the frame and it was placed so that one opening was in the cage and the other outside. Using this system with cabbage during the current winter adequate bee activity has been observed in the cages. Loss of bees has been of no consequence and the colonies are progressing much better than when caged. A check on possible crossing should be obtained since there is a flowering broccoli field within flight distance.

4. Inheritance of resistance in carrot, Daucus carota var. sativa to the leaf spot fungus, Cercospora carotae

F.F. Angell and W.H. Gabelman

Department of Horticulture, University of Wisconsin

A greenhouse seedling test was used to screen experimental carrot lines for resistance to Cercospora carotae (Pass.) Solheim and to assay lines segregating for resistance. Variability within tests was minimized by using a highly pathogenic fungus isolate, high inoculum concentration, and controlled temperature. Highly reproducible results were obtained when inbred lines, F1 hybrids, and segregating populations were tested. Greenhouse disease ratings were in agreement with field ratings.

A single dominant gene in the experimental inbred line WCR1 was shown to control Cercospora leaf spot resistance when tested against four different sources of susceptibility. Single dominant gene control of purple petiole in the experimental inbred line TS1 was also shown. There was independent inheritance of the single genes controlling Cercospora resistance and purple petiole.

5. Longitudinal Cracking in Carrots

M.H. Dickson

New York State Agricultural Experiment Station, Geneva

Cracking is a serious problem in many carrot varieties but especially in the Nantes types. The extent of natural cracking varies considerably depending on the age of the root and on the seasonal variation of the environment, especially soil moisture. By pricking the root with a knife it is possible to distinguish plants with a genetic tendency to crack but not expressing it phenotypically, irrespective of the seasonal variation. It was found best to jab the root about 1/3 of the way down with a fairly broad bladed pocket knife. This should be done as soon as possible after the roots have been pulled from the soil; if they are allowed to lie for even ten minutes they will start to wilt and will not crack so readily. Using this technique, it was found that inbred lines which cracked anywhere from 0 - 50% in many cases cracked 100% using the pricking technique, while other lines would not crack at all. It appears that cracking is dominant to non-cracking.

6. Use of Antibiotic in the Breeding of Celery

Shigemi Honma

Department of Horticulture, Michigan State University

Loss of selected matured celery plants from soft rot when moved from the field to the greenhouse for seed production was greatly reduced by spraying the crown with antibiotic. Plants were sprayed with Agrimycin at a concentration of 100 ppm at weekly intervals from transplanting to seed maturity.

7. Crosses Among Cucumis Species

C.F. Andrus and George Fassuliotis

U.S. Vegetable Breeding Laboratory, Charleston, S.C.

Fassuliotis and Rau (Pl. Dis. Reptr. 47(9):809. 1963) confirmed the earlier observation of Winstead and Sasser (Pl. Dis. Reptr. 40:272-275. 1956) that Cucumis anguria, the West Indian gherkin, has a high level of resistance to the cotton rootknot nematode. The apparent absence of such resistance in any cultivated stocks of either Cucumis melo (cantaloupe) or Cucumis sativus (cucumber) led us to start a series of interspecific crosses within the genus. Thus far the following crosses appear successful:

The F1 hybrid of C. anguria x C. hookeri is self-fertile and also appears to be fertile in outcrosses to the species C. anguria, C. africanus, C. hardwickii, C. ghetto, C. humifructus, and C. myriocarpus, and the the hybrid of C. zeyheri x C. longipes. Most other F1 hybrids show partial to complete self-sterility and outcross only selectively. Many possible crosses have not yet been tested. Among these crosses attempted there have been many kinds and degrees of sterility, but there is hopeful indication that among the hybrids one will be found through which the barrier to hybridization of C.anguria x C. melo can be overcome. A few seed of some interspecific hybrids can be supplied to other breeders if requested.

8. Gibberellin on Cucumbers

W.C. Barnes

Clemson University Truck Experiment Station

The use of gibberellin to induce flowering in gynoecious cucumbers has not worked out as well as desired, especially in the western seed growing areas. It has been found that the dosage must be varied according to the genetical line being treated. For example, it requires at least 1500 ppm to give as good results with SC 54 slicer as it does with SC 3 pickle. Of even greater importance has been the necessity to vary interval according to plant growth. Once a week appears to be adequate in early spring but an interval of 4 to 5 days has been necessary to obtain equal results when plantings were made in August. All treatments have been started in the cotyledon to first true leaf stage.

9. Further Studies on Polyploidy in Cucumis sativus L.

J.L. Bowers

University of Arkansas

In the 1964 Newsletter, it was pointed out that tetraploid cucumber plants had been obtained by soaking cucumber seed in the cracked seed coat stage and also by applying the 0.2 percent colchicine solution to the growing point of seedlings. Furthermore, it was noted that low fertility (seed production) was encountered in tetraploid plants.

Both acetocarmine and the 1.5 percent tetrazolium chloride solution staining of fresh pollen grains and germination on .2 percent agar media point out that a high percentage of the pollen grains from tetraploid plants are functional. A cross between Gy 34 (gynoecious line) and Pixie at the tetraploid level has resulted in a slight increase in female fertility. Another cross at the tetraploid level between Gy 34 and the Russian accession obtained through Dr. C.E. Peterson has given offspring which show slightly greater seed set than has been observed in the other tetraploid lines.

A program has been started to determine if doubling of F1 hybrids developed from crosses between unrelated parents would give rise to more fertile tetraploids. The tetraploids have been obtained and the first generation from these tetraploids will be grown in the greenhouse this spring. These tetraploids were obtained by both methods of colchicine treatment. The seedling treatment appeared to be more effective in the induction of polyploids than the seed soak treatment.

Some of the characteristics, observed in young seedlings affected by the colchicine, were thickened hypocotyl, thickened cotyledons, white margin around edges of cotyledon that later cracked and the first true leaf as well as subsequent leaves showed more serration in the leaf edges than diploid leaves.

The work will be continued to select for higher fertility and to test triploid hybrids on the basis of seedlessness and productivity.

10. Resistance to Watermelon Mosaic in Cucumber

J.C. Gilbert and Jack S. Tanaka

Department of Horticulture, University of Hawaii

Watermelon mosaic virus is commonly present in both commercial cucumber plantings and experimental fields at lower elevations in Hawaii. Local growers have complained that the "mosaic resistance" attributed by seed catalogs to new varieties and hybrids from the mainland does not hold up here in many cases. Since 1949 the Hawaii Agricultural Experiment Station has been testing cucumber accessions and selections to discover potential sources of resistance to combinations of the more common cucurbit viruses present here. As a result of hand inoculations of seedlings, a single plant selection made in 1950 from seed supplied by Dr. Munger was found to differ from the parental line in both a greater tolerance to W.M.V. and in a number of fruit characters. The latter were inferior to the parental line but the resistance to both cucumber and watermelon mosaic was established in various derivatives and has always proved better than anything else received here in subsequent tests. Seed from this source was supplied to any who asked for it under the local name "Ilima" and, when resistance to powdery mildew was added, under selection numbers such as 60-G-8. In the latter, the first number refers to the year and the letter in the middle to the planting in that year's series.

In crosses with the Cornell line, 55-740, there appeared to be a single recessive gene in Ilima which conferred the added tolerance to watermelon mosaic. Both lines were resistant to cucumber mosaic here. Because of possible strain variations in these viruses, no published statements were made regarding the additional mosaic resistance in the Ilima selection. More recently it has been found that some strains of W.M.V. or combinations with other viruses appear capable of producing some foliar symptoms on lines with the Ilima type resistance but that the latter still grow well and produce marketable fruit in plants inoculated by aphids. The cucumber mosaic resistant hybrids from commercial sources were stunted and died sooner than the former in these tests. This suggests that this partial resistance to watermelon mosaic virus should be retained and added to commercial types in areas like Hawaii where W.M.V. is a common problem. New hybrids with this type of resistance have outyielded the most popular C.M.V. resistant commercial hybrid here by a ratio of nearly 3 to 1 when the added resistance was present in both parents. These field grown plants were subject to natural (aphid) inoculation only.

11. Pipe Cleaners as Flower Closures

R.M. Bailey

Maine Agricultural Experiment Station, Orono

For several years, we have used sections of pipe cleaners as flower closures for hand pollination of melons, cucumbers and squash. The cleaners are cut to lengths appropriate for the species to be pollinated. They are soft enough not to injure the flowers, flexible enough to be readily applied and sufficiently rigid to keep the flowers closed.

12. Breeders Stock of Maine 41-60 Melon

R.M. Bailey

Plants and Soils Department, University of Maine

A small supply of Maine 41-60, monoecious flowered inbred melon line (C. melo), is available for distribution. This line may be of interest in the production of experimental early hybrids. Up to 100 seeds will be sent, as long as the supply permits, to breeders who make requests.

13. Mosaic Tolerance in European Cantaloupes

H.M. Munger

Department of Plant Breeding, Cornell University

In 1964 we had a melon planting which included a wide range of types. Cucumber mosaic began to appear in the planting at blossoming time and gradually spread through it. Two European cantaloupes, Hochgenuss and Charentais, showed some mottling of leaves but markedly less stunting than our commercial varieties.

By the time fruit began to ripen, virtually every plant in the field showed mosaic symptoms. At this point "sudden wilt" appeared; i.e. rows in the first stages of maturing fruit would suddenly wilt and plants would be essentially dead within a week or ten days. The European cantaloupes did not show "sudden wilt," nor did some of our breeding lines which have cucumber mosaic resistance approximately as resistant to C.M.V. as the average of our breeding lines although probably not as good as the best.

These cantaloupes do not have attractive outer appearance, being non-netted, but their depth of flesh, orange flesh color, and flavor are excellent. They are slightly late in maturity for New York conditions. In additions to its apparent mosaic tolerance, the strain of Charentais we grew is one selected for fusarium resistance in France under conditions where Delicious 51 and Iroquois are not resistant (1).

These cantaloupes may represent a unique combination of disease resistance and high quality. Small seed samples are available for interested breeders.

Reference

  1. Messiaen, C.M., Georgette Risser et P. Pecaut. 1962. Etude des Plantes Resistantes au Fusarium oxysporum f. sp. melonis dans la Variete de Melon Cantaloup Charentais. Annales Amelioration des Plantes 12(2): 157-164.

14. A New Source of Genic Male-Sterility in Cucurbita pepo

H.M. Munger

Department of Plant Breeding, Cornell University

In the fall of 1962, Mr. Hamdy M. Eisa showed me a male-sterile plant of Cucurbita pepo which he had found in the process of inbreeding the 'Balady' or 'native' variety of summer squash at the Vegetable Research Station, Ministry of Agriculture, Dokki, U.A.R. His results indicated that it was probably a genic recessive. The fruit and plant were similar to Zucchini except that the fruit was light green in color, as desired in Egypt.

Mr. Eisa supplied a seed sample, presumed to be segregating, and it was given the PI number 288,241. No male-sterile plants appeared in plantings at Ithaca or Geneva in 1963, but Dr. Dolan of the Regional Plant Introduction Station at Geneva, N.Y. made a number of sib pollinations. This seed produced one (1) male sterile plant in a row of about 6 plants at Ithaca in 1964. Meanwhile, Mr. Eisa supplied some additional seed samples which were also planted at Ithaca in 1964. In one row of 13 plants, 2 male steriles were found. Nine fertile plants in this row (64-173) were selfed and their progenies grown in the greenhouse in the fall of 1964. Two of the 9 progenies consisted of fertile plants only. The other 7 progenies produced 47 male-sterile plants in a total of 162 plants, in agreement with Eisa's hypothesis that a single recessive gene is responsible for male-sterility.

Small samples of the selfed segregating progenies will be supplied to anyone interested in working with this male-sterile squash. Male-sterile plants can be identified easily by examining the male flowers or buds as early as when they are only about 1/2 inch long.

Dr. Oved Shifriss indicated in correspondence that the recessive male-sterile he described in C. pepo (Jour. Hered. 36:47-52. 1945) is no longer in existence to his knowledge and encouraged the introduction of a new source of this character. If by chance anyone does have the Shifriss male-sterile, we would appreciate a seed sample in order to make comparisons with the new one.

15. Cucurbita Species Crosses as a Source of Resistance to Powdery Mildew

Thomas W. Whitaker

U.S. Department of Agriculture, La Jolla, California

Cultivars of the four annual species of Cucurbita, C. pepo, C. mixta, C. moschata and C. maxima, are extremely susceptible to the powdery mildew fungus, Erysiphe cichoracearum. We have tested hundreds of accessions of these species without uncovering a single item with a satisfactory level of resistance.

Cucurbita lundelliana, a wild species, indigenous to Southern Mexico and Northern Guatemala, has considerable resistance but is not immune to powdery mildew (Whitaker, 1956). On C. lundelliana foliage the fungus does not sporulate freely, and if the plants are not subject to repeated reinoculation there is little if any damage from the parasite. Rhodes (1964) has shown that C. lundelliana-type resistance is controlled by a single dominant gene.

Cucurbita lundelliana crosses readily with C. maxima and C. moschata, but with some decrease in fertility. Commencing in 1952, C. lundelliana was crossed with C. maxima cv. 'Banana'; then followed two crosses with C. moschata cv. 'Large Cheese'. After 4 generations of selection and selfing, several relatively stable lines have emerged with much more resistance to powdery mildew than the susceptible parents. They also have a reasonable amount of fertility. Nothing is known about the consumer quality of the flesh, but flesh color, flesh thickness and shape of the fruit is acceptable compared with the cvs. 'Butternut' and 'Large Cheese'. Under conditions at La Jolla, California, the vines are vigorous and prolific. As anticipated there are recognizable characters from all three species in these combinations.

A limited amount of seed will be available to interested breeders.

References

  1. Rhodes, A.M. 1964. The inheritance of powdery mildew resistance in the genus Cucurbita. Plant Dis. Rptr. 48(1):54-55.
  2. Whitaker, T.W. 1956. The origin of the cultivated Cucurbita. Amer. Nat. 90:171-176.

16. Effect of Maturity of Lima Bean Pods on Germination and Vigor of Seedlings

R.E. Wester and J.W. Metzler

Low seed germination of Fordhook 242 in the field and some green-seeded Fordhooks (U.S. 561, 861, and 1061) in 1963 and 1964 pointed up the importance of determining some of the factors that may influence seed germination and vigor of lima bean seedlings.

At Beltsville, Maryland, in 1964, pods of Fordhook 242, a white cotyledon variety, and two green-seeded Fordhooks (U.S. 861 and 1061) were harvested at three stages of maturity. They were (1) green mature, (2) pods starting to dry, and (3) completely dry pods. The green mature and pods starting to dry were air-dried slowly in a greenhouse and the seed was shelled out by hand at the same time as the field-dried pods. Germination tests were conducted in sterile moist sand in a warm greenhouse, night temperatures of which were 70 to 75? F and day temperatures of 80 to 85? F.

Highest germination and most vigorous seedlings from all lots of seed was from green mature pods and the lowest germination was from pods that were allowed to dry completely in the field. The seed from the green mature pods was bright and clean while the seed from the field-dried pods was weather stained and infected by fungi. It was also observed that there was more bleaching of chlorophyll from the cotyledons of 861 and 1061 due to exposure to the sun during the field drying period of the pods.

According to this single season's study, it appears that in order to obtain lima bean seed of the Fordhook types of high germination, pods should be harvested when green mature and air-dried slowly during the curing process.

17. Variations in Fruit Carpel Number of Varieties and Strains of Peppers

A.E. Thompson, M.C. Chu, and A.K. Stoner

Department of Horticulture, University of Illinois, Urbana

A collection of 104 entries of 41 varieties and strains of peppers were grown in a replicated trial at Urbana, Illinois in 1963. A total of 2100 plants were classified for carpel number distribution by observing sectioned fruits. Visual observations of lobe numbers of whole fruits do not always correlate perfectly with carpel number. Small carpels frequently do not result in visible lobing of the apical end of certain fruits.

The experimental design was a split plot with 2 replications. The subplots for the 2 methods of sampling, each contained 5 plants. Records were taken on individual plants at weekly intervals. One sampling method consisted of harvesting and classifying all fruits set on a plant. A total of 9 harvest were made. The second method consisted of harvesting and classifying only mature fruits, i.e. those fruits at a marketable stage of maturity. A total of 7 harvests were made for the latter method.

Table 1. Comparison of two methods of sampling for distribution of carpel number of 41 varieties and strains of peppers.

Distribution of carpel numbers

Sampling method

2

3

4

5

6

7

8

Mean carpel number

Number of fruit sampled

Immature fruit

#

1354

14614

10522

791

26

3

1

3.397

27311

 

%

4.958

53.510

38.526

2.896

.095

.011

.004

Mature fruit

#

254

4133

3692

328

16

1

0

3.492

8424

 

%

3.015

49.062

43.827

3.894

.190

.012

0.00

Total population

#

1608

18747

14214

1119

42

4

1

3.420

35735

 

%

4.500

52.461

39.776

3.131

.118

.011

.003

The number of carpels ranged from 2 to 8. A highly significant difference was obtained between the two sampling methods (Table 1). A shift to a higher mean carpel number was obtained with the second method (marketable stage of maturity). A possible explanation is that abscission of fruits with lower carpel numbers may be greater than those with high numbers. The removal of all immature fruits at weekly intervals may also have exerted an effect on the physiology and developmental morphology of the fruits in the first sampling method.

Variation associated with season or harvest date has not yet been analyzed. In any event, it is clearly evident that environmental factors greatly modify the expression of carpel number both within and between plants. Table 2, which lists the distributions of carpel numbers summed over both sampling methods and harvest dates, shoes the extent of variation that exist between varieties and strains of peppers. Undoubtedly a sizeable component of this variation is heritable and amenable to selection. A program of selection for both high and low carpel number is currently in progress. An attempt will be made to assess the relative contribution of heritable and environmental components of variation.

Table 2. Distribution of carpel numbers and mean carpel number of 104 entries of 41 varieties and strains of peppers.

Distribution of carpel numbers (%)

Variety or strain

Number of entries

2

3

4

5

6-8

Mean carpel number

Number of fruit sampled

New Hampshire #PG-62

1

14.5

66.4

19.0

0.1

0

3.05

920

Burpee's Hybrid 61-2

1

13.6

61.9

23.6

0.9

0

3.12

649

Wisconsin Lakes

1

12.7

63.8

22.2

1.0

0.2

3.12

481

Pennwonder

2

11.8

64.0

23.9

0.3

0

3.13

1393

Vinedale

1

11.4

64.0

23.9

0.7

0

3.14

439

Early Bountiful

1

12.2

61.9

25.3

0.6

0

3.14

727

Pimento types

3

9.2

65.0

25.5

0.3

0

3.17

380

Yellow Oshkosh

1

9.2

62.0

27.9

0.9

0

3.21

326

Sunnybrook

3

8.5

61.6

29.2

0.7

0

3.22

1619

Michigan State 61-535-1

1

5.6

61.9

31.9

0.6

0

3.28

661

Italian E1

1

5.4

61.0

32.7

0.8

0

3.29

590

Michigan State 60-38-n

1

5.5

58.2

34.8

1.5

0

3.32

603

Cuban

1

3.2

60.9

34.8

1.2

0

3.34

506

Large Early Neapolitan

2

3.5

61.0

32.4

3.0

0

3.35

1216

Early Wonder

1

4.1

57.4

36.7

1.8

0

3.36

169

Florida Giant

4

4.0

58.2

35.2

2.5

0

3.36

945

Burpee's Fordhook

1

5.3

54.7

37.3

2.6

0.1

3.38

855

California Wonder

8

4.2

55.6

38.6

1.5

0.1

3.38

2015

Yolo Wonder

13

4.7

54.8

38.0

2.4

0.1

3.38

2706

Wondergreen

1

1.6

58.2

40.2

0

0

3.38

122

Calwonder

7

3.9

53.1

41.1

1.9

0.1

3.41

1685

Oakview Wonder

2

2.6

54.8

38.4

4.0

0.2

3.44

500

Rio Wonder

2

4.0

49.3

45.0

1.4

0.3

3.45

349

Merrimack Wonder

1

1.7

53.2

42.1

2.9

0.1

3.46

867

Staddon's Select

1

3.0

51.6

41.4

4.0

0

3.46

473

Delaware Belle

5

2.7

50.8

43.6

2.7

0.2

3.47

2392

Aconcagua

1

1.2

47.3

50.9

0.6

0

3.51

165

Ruby King

2

1.6

48.6

45.8

3.8

0.1

3.52

888

Lincoln Bell

4

1.7

46.9

49.0

2.2

0.2

3.52

2051

World Beater

5

1.2

48.7

45.6

4.2

0.3

3.54

1397

Allbig

4

1.8

46.6

47.5

3.9

0.2

3.54

1327

Keystone Resistant Giant

5

1.5

42.8

50.4

5.2

0

3.59

789

Illinois #6

3

1.7

41.7

50.6

5.8

0.1

3.61

861

Illinois #4

2

1.2

41.2

52.7

4.7

0.2

3.62

427

P-1 Hybrid

1

2.2

36.9

55.9

5.0

0

3.64

222

King of the North

1

0.9

38.8

54.7

5.6

0

3.65

338

Idabelle

1

2.1

36.0

57.1

4.2

0.5

3.65

189

Chinese Giant

1

0.4

24.9

68.1

6.6

0

3.81

257

Illinois #2

3

0.7

28.8

57.8

12.0

0.7

3.83

922

Illinois #1

2

0

22.4

57.5

19.3

0.8

3.98

379

Illinois #3

3

0.2

19.3

56.4

22.7

1.4

4.06

585

18. Effect of Day-length on Peruvian Corn

E.A. Kerr

Native Peruvian corn was grown in 1962. It had exceptionally deep kernels and appeared to be flour corn. It was claimed to be the nearest to sweet corn that the natives were growing. No tassels had appeared by October 1 although the stalks reached a height of 14 feet. The tassels developing inside the stalks were 6- to 8- foot level.

In 1963, several plants were covered with bushel hampers to reduce the day-length to 8, and to 12, hours for 2 weeks in the early seedling stage. These plants came into tassel during August and September. Pollen was obtained and crosses made with three commercial sweet corn hybrids. On the Peruvian variety itself, long-shanked ears were formed but the silks did not elongate and no seed was produced.

In 1964, some of the commercial hybrid x Peruvian plants were given a short-day treatment of 9 hours. Tassels and silks appeared on both treated and control plants but the treatment hastened their appearance by about 2 weeks. In general, these F1 plants produced short ears with a long tassel tip. The row count was high. The kernels were deep but not superior to some commercial hybrids. All the kernels on some ears had sugary endosperm indicating that at least some of the kernels of the accession were heterozygous. The inheritance of the reaction to day-length has not been determined.

19. Release of Sweet Corn Inbred Ma-21565 by the Massachusetts Agricultural Experiment Station

W.H. Lachman

Sweet corn inbred Ma 21565 was developed in 1956 from a single plant selection of Ma 21547-1-1 during a test for resistance to bacterial wilt (Bacterium stewartii). The plants of the two inbreds appear to be identical in gross characteristics, however, in tests conducted at this station the seed yield of Ma 21565 has been approximately 35 per cent greater than Ma 21547. Inbred Ma 21565 is much less subject to ear rot diseases, the seed quality is improved, the ears tip out better and the row-count of kernels is slightly greater. The general description of Ma 21565 is as follows:

Combines well with C13 and certain other early inbreds. It can be used as either seed or pollen parent. The quality is good. It shows good tolerance to both Bacterium stewartii and Helminthosporium turcicum.

Germ plasm quantities of seed are available to research workers and seed companies.

20. A Quick Method for Estimating Viscosity in Tomatoes

O.H. Pearson

This article appears in the Tomato Genetics Cooperative Newsletter issued in February, 1965. The title is cross-referenced here to call attention to it.

21. Effects of Fermentation on Germination of Tomato Seed

R.L. Lower and C.H. Cadregari

For many years tomato seed has been cleaned by allowing the seeds, pulp and juice of ground up tomato fruit to ferment for a given length of time. Germination rates of the majority of seed lots cleaned in this manner have been satisfactory. However, a very few lots of tomato seed cleaned by the fermentation process have been low in germination and rates of others have been somewhat erratic. One of the reasons for this poor germination is now thought to be due to excessive fermentation in the seed cleaning process. Differences in varietal response to the duration of fermentation have been very striking.

Samples were taken daily from agitated and non-agitated barrels of fermenting pulp and seed. Germination of seed from variety A was 95% after 3 days of fermentation, 84% after 5 days, 50% after 7 days, and 20% after 12 days. This behavior is very different from that of variety B. Germination of seed from variety B was in excess of 94% after 7 days fermentation and was still above 90% after 12 days and 60% after 21 days.

The varietal responses to fermentation are under further consideration at the present time.

22. Effects of Nematode Infections on Yields, Fruit Size and Soluble Solids of Tomato Fruits

Zidan E. Abdel-Al

An experiment was designed to test the effect of nematode infection on yields, fruit size, number of fruits and total soluble solids of the fruits. Two main varieties grown in the United Arab Republic mainly for export were selected. The varieties were Money Maker and Stoner. The experiment was designed as a split plot. There were two treatments, each treatment consisted of 5 pots. One of the treatment was infected with nematodes. Each pot in that treatment received 200 grams of macerated galled tomato roots. The other treatment was considered as a control. The total yield is shown in Table 1.

Table 1. The yields of healthy and infected tomato varieties.

Average yield per 5 plants in kg

Variety

Healthy

Infected

Money Maker

1.526

.872

Stoner

1.525

.629

 

The fruit size was determined and shown in Table 2.

Table 2. The fruit size of healthy and infected tomato varieties.

 

Fruit size in grams

Fruit size in grams

Variety

Healthy

Infected

Money Maker

21.8

18.5

Stoner

26.5

16.2

The number of fruits per plant is shown in Table 3.

Table 3. The number of fruits per plant of healthy and infected varieties.

Average number of fruits per plant

Variety

Healthy

Infected

Money Maker

14

9.4

Stoner

11.8

8

 

The percent soluble solids of fruits taken from healthy and infected plants was determined and shown in Table 4.

Table 4. Percent soluble solids of fruits of healthy and infected varieties.

 

Percent soluble solids

 

Variety

Healthy

Infected

Money Maker

6.82

6.05

Stoner

6.50

6.17

The greenhouse experiments indicated that nematode infection reduced the yields by 50 percent. The fruit size of Stoner was seriously reduced by 38.8 percent. The reduction in the number of fruits per plant was approximately 32.6 percent. The total soluble solids of fruits was decreased by 8.2 percent. The differences were highly significant. The field experiment is shown in Table 5.

Table 5. The average yield per plant of four tomato varieties grown in a nematode infested and Vapam treated soil.

 

Yield in kilograms per plant

 

Variety

Vapam treated

Infested soil

Anahu (resistant)

0.430

0.440

Victory

0.285

0.193

Stoner

0.679

0.398

Shyenne

0.490

0.340

The field experiment agreed with the greenhouse experiments. The yields of Anahu were not affected when grown in a Vapam treated and an infested soil.

23. Notes on BIRDSNEST Tomato Type

T.O. Graham, B. Heeney, L.H. Lyall, and L.F. Ounsworth

In 1954, L.F. Ounsworth of the Research Station, Canada Department of Agriculture, Harrow, Ontario crossed the tomato selection South Carolina W. St. 104-2 with the variety Harrow. From this cross William Shumovich, while working at Harrow in 1956, selected out plants with a different type of growth which he designated and later distributed as BIRDSNEST.

In the ordinary tomato the leaves curve outward and spread out over a row. With the original BIRDSNEST type the leaves curve inward and circle over the fruit. The fruit appears to be nesting within a layer of incurved leaves and for this reason the term BIRDSNEST was used.

It was recognized that the 'nesting' fruit might be protected by the incurved leaves from rough mechanical damage. By 1964 three institutions in Ontario were active with BIRDSNEST type and the resulting pedigrees, as of 1964, will follow.

The first pedigree mentioned traces to Lloyd Lyall, Canada Department of Agriculture, Research Station, Ottawa. He has succeeded in transferring hp or high pigment to the BIRDSNEST type. The second pedigree given traces to Dr. B. Heeney and J.D. Metcalf, Smithfield Experimental Farm, R. R. #4, Trenton. This stock has the ability to germinate in cool soils. The third pedigree traces in part to the Ontario Agricultural College at Guelph. It is the result of a cross made by Dr. L. Butler, Department of Zoology, University of Toronto. In this last cross all efforts carried out so far at Guelph by Dr. Butler and Professor T.O. Graham to combine Crn1 Crn1 crn2 crn2 , or the crimson gene combination, with the BIRDSNEST type have failed.

  1. BIRDSNEST x (Redtop x Webb Special) F6
  2. BIRDSNEST x (Ottawa 6 x Manitoba) F6
  3. BIRDSNEST x Crn1 Crn1 crn2 crn2 F5

BIRDSNEST could prove an ideal type for machine picking. This point will be investigated by Professor J.H. Lee just as soon as sufficient seed in on hand to keep machine picking experiments on an acreage basis.

24. Work With High Crimson Variety -- 1964

T.O. Graham

The present High Crimson variety carries the ug gene or, in other words it has a slight tinge of darker green on the stem end of the fruit. Fruit carrying ug are generally more prone to cracking than those carrying u, or uniform green fruit. Out of 1300 plants three High Crimson plants were located carrying the u or even-ripening gene. These have been previously noted as Stock 4, plant 9; Stock 48, plant 3; Stock 58, plant 6. Every effort will be made to move High Crimson variety over into a more crack resistant and possibly uniform ripening or u form.

With High Crimson the blossom-end scar is often too prominent. To counteract this High Crimson has been crossed with USDA P.I. 263726 which traces to Puerto Rico, and F1 seed is on hand. This Puerto Rico stock has a small scar, is u, and is very resistant to cracking.

Plants carrying intense crimson fruit color possess a long straggly vine. To get away from this, many long-vined crimson-fruited plants have been crossed with sp or self-pruning types. Over 5000 plants have been grown from such crosses but it has been found impossible so far to combine self-pruning or sp with Crn1 Crn1 crn2 crn2 or the crimson gene combination. For this reason the previously mentioned cross with 263726 from Puerto Rico will be watched with special interest as 263726 carries both the u and sp genes. Many other varieties and selections carrying this or similar combinations have been crossed with High Crimson and they are in part as follows: Morden 262, Libby c-49, Heinz 1350, South Carolina Leaf Retentive, and Florida 2-D2-D1-D3-VAStW.

The cross between High Crimson and Campbell C1327-Bsp has even more intense crimson flesh color than the High Crimson variety. There are eight different F6 lines of this cross on hand and these may be grown at Leamington in 1965. When this cross is backcrossed to High Crimson the F1 looks promising. Two other backcrosses show promise and they are as follows:

(Cold Set x High Crimson) x High Crimson

(High Crimson x Blitz) x High Crimson

The last mentioned cross High Crimson x Blitz traces to the Canada Department of Agriculture at Smithfield, Ontario. This backcross has been distributed to many processors in Ontario.

The commercial tomato has yellow colored flowers. With High Crimson orange-flowered forms were located in 1960. It has been found under intense sunlight that flowers which would normally be orange are yellow instead. An attempt is being made to stabilize the orange color so that it will appear in the flowers even when they are subjected to intense heat.

Seed of og or flowers carrying the old gold gene was obtained from Dr. John E. Boynton of the University of California. Indoors, and under winter conditions at Guelph, the og gene produces tangerine orange flowers as compared to the yellowish orange flowers produced under similar conditions by the High Crimson variety.

The old gold or og flowers eventually produce fruit with intense red color almost equal visually to the High Crimson variety. Old Gold has been crossed with High Crimson to see if an orange flower can be combined with High Crimson and remain stabilized under intense heat.

It is too early as yet to state that the color of the flower can be used as a marker to indicate the intensity of pigmentation in the fruit. This point can be studied if it is possible later to create lines with 100% of the plants presently with orange flowers. We are, however, at the present time using orange flowers as a marker for the crimson gene combination in segregating populations.

Another new flower color has been located. Stock 66, plant 5 of the High Crimson variety mutated in 1965 from orange to brown colored flowers. It has intense crimson flesh.

In the winter of 1963-64 over 8000 plants of the cross Crimson s11 x divergens were grown to see if a combination between divergens (di) and stamenless (s1) could be produced. Both are situated on chromosome 4. No plants carrying the combination were located but the fruit colors which resulted are of interest and could be of value. Three colors new to the tomato may have been located namely brown and purple external fruit color, and apricot flesh color. Orange color was located in 1963 and 1964 in the epidermis or peel.

25. Location of the Crimson Factor in Tomato

M.L. Tomes, H.T. Erickson, and R.J. Barman

The Crimson character, first described by Butler, has been of tremendous interest to tomato breeders because of enhanced fruit color. T.O. Graham in his mimeo "Work With High Crimson -- 1964" reports that more than 5000 plants from crosses between self pruning (sp) and Crimson failed to yield a self pruning - crimson recombinant.

Since Crimson lowers the beta-carotene content, and gene B enhances the beta-carotene fraction, we were interested in the combined effect of Crimson and B. A small F2 of the cross BB x Crimson was classified in the greenhouse. Of a total of 37 plants, 9 were red fleshed. Of these 9, 8 were classified as Crimson.

These results can be explained if the Crimson factor (or one of the Crimson factors, if there are two, as postulated) is linked to B. B is known to be closely linked to sp. Thus, the Crimson factor (or one of them) must be on chromosome 6 near sp and B. If there are two Crimson genes, Cr1 Cr1 cr2 cr2 several possibilities exist: (1) the BB parent already carries one of the genes, (2) the recessive is the linked factor, thus most of the red recombinants carried the unlinked dominant Cr1, or, (3) both factors are linked to sp and B. Otherwise, even in this small F2, it is difficult to account for this proportion of Crimson plants among the red recombinants.

If these deductions are correct, Crimson should be fairly closely linked to potato leaf (c) and old gold flower (og). Graham has a Crimson stock with orange flowers and he has been using orange flowers as a marker for the crimson gene combination in segregating populations. Combinations with potato leaf, or self pruning (if possible) might also serve as markers which are less difficult to classify.

26. An Improved Method of Separating Watermelon Seeds from the Pulp

Charles M. Jones

The standard methods of separating watermelon seeds such as fresh washing or fermenting to affect breakdown of the cells are somewhat unsatisfactory in that fresh washing is laborious while fermenting is unpleasant and may result in seed damage if treatment is prolonged. A pectinase enzyme, Pectinol 100-D from Rohm and Haas, was investigated for its effectiveness in promoting the breakdown of the pulp of watermelon without damaging the seeds. Three levels of enzyme for two time periods were compared with fresh washing, fermenting for four days, and treatment with 5% HCl.

Acid treatment definitely lowered the germination. Fermentation seemed to lower the germination slightly but not significantly. Fresh washing and pectinase treatments gave seeds with equal germinability. The pectinase treatment was tried on hard-fleshed citron types and was very effective in these types, also.

The pectinase treatment was not tried on tetraploid seeds but its trial use is clearly indicated in view of the relatively tougher flesh of these types and the greater susceptibility of tetraploid and triploid seeds to the fermentation process. The enzyme is relatively inexpensive and is readily available. A treatment of 0.2% by weight for about two days would apparently give adequate breakdown of the flesh of watermelons while still not damaging the seeds.

27. A New Dwarf Cucumber Mutant

R.W. Robinson and W. Mishanec

The interest in dwarf cucumbers for mechanical harvesting prompted us to search our stocks derived from thermal neutron seed treatment in previous generations for new mutants that might be useful. Several interesting types were found and are under study now. One of them appeared especially promising. Internodes of this mutant are extremely short and the plant is very compact.

This dwarf mutant originally was of very poor horticultural type, since it was induced in the variety Lemon, but segregants with good fruit type occurred in the F2 of a cross with Wisconsin SMR 18. In general, the dwarfs had shorter fruit than did normal vine types of this F2, but many of the dwarfs had acceptable fruit length to diameter ratio and their fruit remained in the desirable stage for a longer period of time.

This dwarf mutant should be a good marker gene for genetic studies but it is too early to know if it will be useful for breeding. At least two problems will have to be overcome by selection to make practical use of this mutant; the dwarfs had undesirably short peduncles and low seed production.

All F1's between dwarfs and normal had normal plant habit. Segregation in several F2 families totaled 580 normal to 151 dwarf. There was a significant deviation from a 3:1 ratio (X2 = 7.3, p = < .01) and significant heterogeneity between F2 families; some families being in close agreement with 3:1 while others were deficient in dwarfs. It is concluded that the dwarf habit is conditioned by a single recessive gene with differential variability, which we are naming dwarf-1 (dw1).

 

28. Suggestions For Topics

Shigemi Honma, Chairman

Suggestions for topics to be discussed at our Vegetables Breeding and Variety Committee meeting to be held next August, during the ASHS meeting mail your suggestions to Shigemi Honma, Department of Horticulture, Michigan State University or to any of the committee members: Dr. John Bowers, Dr. E.M. Meader, Dr. Elmo Davis, Dr. Lincoln Pierce, Dr. Phillip Minges, Dr. Robert Soost or Mr. Iver Jorgensen.

29. Uncatalogued Vegetable Varieties Available for Trial in 1965

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, with lima beans and sweet corn listed under "L" and "S". 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.

30. Stocks Desired