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Cucurbit Genetics Cooperative Report 22:v-ix (article 0) 1999

Cucurbitaceae 2000

VIIth EUCARPIA Meeting on Cucurbit Genetics and Breeding

Cucurbitaceae 2000, the VIIth Eucarpia Meeting on Cucurbit Genetics and Breeding, will be held in Israel on March 19-23, 2000. The meeting will offer the opportunity to get together and discuss the latest developments in cucurbit genetics, breeding, germplasm enhancement, pathology and related fields. This promises to be an exciting scientific program, and a unique opportunity to visit Israel in the year 2000.

The meeting will convene at the Ma'ale Hachamisha Resort and Convention Center, situated in the beautiful Judean Hills on the road to Jerusalem. All sessions will take place at this venue, and the meeting will be conducted in English.

The Organizing Committee for Cucurbitaceae 2000 consists of Nurit Katzie (Chair), Ron Cohen, Menahem Edelstein and Zvi Karshi, all of Newe Ya'ar Research Center, ARO. The Advisory Board includes Shlomo Cohen (Volcani Center, ARO), Yigal Cohen (Bar-Ilan University), Guy Elyashiv (Zeraim Ltd,), Haim Nerson (Newe Ya'ar Research Center, ARO, Rivka Offenbach (R&D Arava), Harry S. Paris (Newe Ya'ar Research Center, ARO), Rafael Perl-Treves (Bar-Ilan University), Arthur Schaffer (Volcani Center, ARO) and Eyal Vardi (Hazera Ltd).

The Ma'ale Hachamisha Resort and Convention Center is a 30 minute drive from Ben Gurion International Airport and a 15 minute drive from Jerusalem. The hotel has spacious, air-conditioned guestrooms with private baths, radio, telephone and TV. A full range of indoor and outdoor recreation facilities are available. These include Spa and Health Club, offering an indoor heated pool and an outdoor swimming pool (in season), tennis courts, lawns and gardens, restaurants and coffee shops.

During the meeting we will visit the Arav, Israel's premier region for winter growing of cucurbits, the Deed Sea and the historical site of Massada. There will be a special program for accompanying persons, and also several options for post-conference tours.

Israel is situated on the crossroads of thee continents and offers a variety of scenic, historical and cultural attractions. Jerusalem, Bethlehem, Nazareth, the Dead Se and many other exciting sites are all within less than a day's drive from the Ma'ale Hachamisha Kibbutz. We welcome you to experience the historical, biblical and modern aspects of this exceptional land and its people.


From the CGC Coordinating Committee: The Call for Papers for the 2000 Report (CGC Report No. 23) will be mailed in October 1999 Papers should be submitted to the respective Coordinating Committee members by 313 January 2000, although the late submissions may be considered if received prior to our processing deadline. The Report will be published by July 2000. As always, we are eager to hear from CGC members regarding our current activities and future direction of CGC.

From the CGC Gene List Committee: Lists of known genes for the Cucurbitaceae have been published previously in HortScience and in reports of the Cucurbit Genetics Cooperative. CGC is currently publishing complete lists of known genes for cucumber (Cucumis sativus), melon (Cucumis melo), watermelon (Citrullus lanatus) and Cucurbita spp. on a rotating basis.

It is hoped that scientists will consult these lists as well as the rules of gene nomenclature for the Cucurbitaceae before selecting a gene name and symbol. Thus, inadvertent duplication of gene names and symbols will be prevented. The rules of gene nomenclature (published in each CGC Report) were adopted in order to provide guidelines for the naming and symbolizing of genes previously reported and those which will be reported in the future. Scientists are urged to contact members of the Gene List Committee regarding questions in interpreting the nomenclature rules and in naming and symbolizing new genes.

From the CGC Gene Curators: CGC has appointed curators for the four major cultivated crops: cucumber, melon, watermelon and Cucurbita spp .Curators are responsible for collecting, maintaining, and distributing upon request stocks of known marker genes. CGC members are requested to forward samples of currently held gene stocks to the respective Curator.


The second announcement, including the "Call for Papers," will be sent in September, 1999 to those who responded to the first announcement. The format for scientific manuscripts will follow that of the CGC Style Guide. For more information, contact the Secretariat/Organizers at:

  • C/O International Travel & Congress Ltd.
  • P.O. Box 29313, Tel Aviv 61292, Israel
  • Tel: +972-3-7951444
  • Fax: +972-3-5107716
  • Email:

Also, the latest information about Cucurbitaceae 2000 can always be found at the CGC website:

CGC Business Meetings

Timothy J. Ng, Chair

The 1998 cucurbit Genetics Cooperative Business Meeting was held on 15 July in charlotte, North Carolina, and was reported on in CGC Report No. 21 (1998). The 1999 CGC Business Meeting was held on 28 July 1999 in Minneapolis, Minnesota, with Dennis Ray (CGC Coordinating Committee Member for watermelon) presiding. A full report of this meeting will appear in CGC Report No. 23 (2000).

Watermelon Research and Development Working Group

Joint Report

Cucurbitaceae /98, Pacific Grove, California (1 December, 1998) and 19th Annual Meeting, memphis, Tennessee (31 January 1999)

Benny D. Brown, Chair.

The Watermelon Research and Development Working Group (WRDWG) met on tuesday, December 1, 1998 in Pacific Grove, California. The meeting was held at the Asilomar Conference Center in Conjunction with the Cucurbitaceae '98. More than 50 people were present and many more turned away because of seating capacity. Seven research reports were presented, generating a lot of discussion. The 19th Annual Meeting of the WRDWG was on sunday, January 31, 1999 in Memphis, Tennessee. The meeting was held at the Peabody Hotel in conjunction with The Southern Association of Agricultural Scientists (S.A.A.S.), the Southern Region American Society for Horticultural Sciences (SR:ASHS), the Southern Region American Society for Horticultural Sciences (SR:ASHS) and the Southern Division: American Phytopathology Society (SD:APS). We had an excellent attendance with more than 50 people present at the meeting. Six research reports, a status report on watermelon germplasm, and a short film on research projects supported by the National Watermelon Promotion Board, were presented to the group stimulating much interest and discussion among the participants. The WRDWG has continued to grow in attendance and influence since its inception. The group has grown from three people in 1982 to more than 50 people in 1999. Dr. Gary Elmstrom was Chairman of the group from about 1982 through 1992. Dr. Ray Martyn was Chairman of the group from 1992 until 1997. We are now a very dynamic group with the common goal of expanding knowledge for the watermelon industry. Consequently, we re indebted to both Dr. Elmstrom and Dr. Martyn for their leadership.

I. Research Updates. One of the more difficult chores that the Chairman has to do is take notes of the research presentations and make sense out of it later. These are brief summaries of the presentations. At the end of each summary, it will be noted which meeting (i.e., C'98, SAAS) the information was presented. You are encouraged to contact the individual scientist if you need additional information.

Dr. George Boyhan [] University of Georgia, discussed the Web Page being developed for WRDWG. Dr. Boyhan has done a lot of work to get the Web Page up and running. We are indebted to him for that. Thanks a lot.

Mr. Ron Kiothera [] and Dr. Anthony Keinath [], department of Plant Pathology and Physiology, Clemson University, are studying the Phoma spp. - Didymella bryoniae complex. There are three distinct groups of fungi that can cause confusion for those working on the gummy stem blight pathogen (Didymella bryonae). they have developed PCR primers (three) to differentiate between Phome cucurbitacearum (didymella bryonae) , Phome I, and Phoma II. Phome II (which has a sexual stage) can be very confusing in culture. There are dramatic differences in the ability of these fungi to cause disease on watermelon. The CR can also be used for testing seed for presence of the respective fungi. (C'98 and SAAS)

Dr. Warren Roberts[] Department of Horticulture, Oklahoma State University, is working toward standardization of variety evaluations and data accumulation. the objective is to form a groundwork for a coalition of workers that would allow for increased uniformity and increased information exchange throughout the watermelon industry. Details need to be worked out as to the specific format, data, and evaluations that will be required. (SAAS)

Mr. Sam Pair [], USDA-ARS, Lane, Oklahoma, gave an overview of the research on Yellow Vine of watermelon. the disease is associated with a phloem-limited bacterium that is likely vectored by a leaf-hopper insect according to his research. The main characteristic symptom is a honey-brown discoloration of the phloem. the disease was first observed in Texas and Oklahoma watermelons in 1991. However in 1998, the disease was confirmed by PCR in Tennessee on watermelon and pumpkin. consequently, the watermelon crop in the southeastern US may also be at risk. (C'98 and SAAS)

Dr.John Damicone [].Department of Entomology and Plant Pathology, Oklahoma State University, is working on control of foliar disease of watermelons with an emphasis on anthracnose. His research has shown that Topsin plus Dithane gave good control as well as Bravo alone. In 1998, Xanthomonas campestris pv cucurbitaceae was responsible for severe defoliation of pumpkin.the disease caused up to 30% defoliation in watermelon in 1997. This is a disease new to Oklahoma and not much is known about the epidemiology. (SAAS)

Dr. Todd Wehner [], Department of Horticulture, North Carolina State University, is testing more than 1200 watermelon PIs for resistance to papaya ring spot virus type W (PRSV-W). PRSV-W was formerly called watermelon mosaic virus 1 (WMV-1). Inoculation methods were developed for the purpose of screening the germplasm, Tests were run to determine the optimum seedling stage for inoculation ranging from the cotyledon to the four true leaf stage. Results indicted that the rub method on the first true leaf was the most satisfactory method to establish symptoms. The most virulent isolate was selected for further evaluations. Testing should be completed by spring of 1999. Dr. Wehner has a list of diploid inbreds (or OPs) that he is collecting seed and pedigree information on. If you can assist, please contact Todd at his email address for the list and any information that you may have. (C'98 and SAAS)

Dr. Joe Norton, Department of Horticulture, Auburn University, gave an overview of his watermelon breeding program over the years which included such releases as AU-Jubilant, AU Sweet Scarlet, and others. He noted that they honey bee population in georgia and many other areas of the United States is critically low. At the present rate, honey bees may become an endangered species which ultimately is impacting cucurbit production. (C'98 and SAAS)

Dr. Tom Zitter [],Department of Plant Pathology, Cornell University, discussed pathogenicity and virulence of Didymella bryoniae. Other nonpathogenic or weakly virulent Phoma species are sometimes isolated from infected tissue, complicating identification of the pathogen. PCR primers can be used to differentiate between Phoma cucurbitacearum (Didymella bryoniae) and other Phoma spp. Twenty D. bryoniae isolates, collected from cucurbits, all caused similar disease reaction on inoculated cucurbits, indicating similarity among Didymella isolates in level of virulence. (C'98)

Dr. Bruce Carle [rbcwm@gnv.ifas.ufl,edu], University of Florida, discussed the situation with race 2 of Fusarium oxysporum f. sp. niveum in watermelon. At present, there is no known commercial cultivar with adequate resistance to this race. Using PI 296341, various crosses have been made to incorporate Fusarium race 2 resistance into horticulturally acceptable material. Good progress is being made in several lines. His virus resistance work in watermelon is also progressing nicely. (C'98)

Dr. Benny Bruton [] USDA-ARS, Lane, Oklahoma, discussed the situation with watermelon germplasm at Griffin, Georgia. A preliminary report was sent out in June,. If you did not get a copy, we will have it on our WRDWG Web Site, which is in the process of being moved to the Lane Research Station in Lane, Oklahoma. The new Web Site should be up and running by September, 1999. The URL will be:

Another topic that was discussed is a seed source for the watermelon differentials for determining race of Fusarium oxysporum f. sp. niveum. Dr. Todd Wehner agreed to get the differential germplasm. test it for purity, and increase it for distribution. Germplasm, can be hard to find and impossible to know the genetic purity. I hope that, in the future, we can find someone to produce the differentials and offer them for sale.

II. News From the National Watermelon Promotion Board (NWPB). Mr. William Watson, [], NWPB Executive Director, was not able to attend due to prior commitments. William did provide the group with a film of research projects that have been supported by NWPB as well as research proposals that have been funded for 1999. The NWPB Board of Directors voted to add two more projects begun last year.

1) A new project at the Lane Research Station, Lane, OK, will investigate the content and health properties of lycopene, a powerful antioxidant in watermelon. USDA-ARS investigator Dr. penelope Perkins-Veaz9e will lead a team of researchers from USDA, Oklahoma State University, and Texas A&M, who will determine yield, stability, and quality of lycopene from marketable fruit and from watermelons considered culls.

2) In another new project, a team of researchers from Oklahoma State University will set up a system to better collect and disseminate production-related research to watermelon industry members. Researchers see a need to regularly communicate and relay information to the watermelon industry about cultivar and pesticide evaluations, fertility rates, and cultural practices. The group hopes to develop a national information exchange group to establish a mechanism for distributing research results and information to all facets of the watermelon industry.

3) The Board of Directors voted to expand the work of Purdue University plant pathologist Richard Latin, who has developed a weather-based prediction system designed to reduce fungicide use without increasing the risk of serious disease outbreaks. The system is called MELCASE (Melon Disease Forecaster). Growers have relied upon MELCAST to provide temperature and moisture readings that enable them to spray at the most opportune time, thereby improving disease control while reducing fungicide costs.

4) The Board also voted to continue University of Florida research by plant pathologist Dr. Don Hopkins who is investigating how to marshal a plant's natural defense system to control disease through chemicals known as plant defense activators. These activators have no direct toxic effect on pathogenic fungi or bacteria and are not classified as fungicides. Early finding indicate these activators are effective in preventing the spread of bacterial fruit blotch in the greenhouse and would be effective in reducing the amount of fruit blotch in the field.

The NWPB has budgeted $50,000 annually through 2001 to support research that addresses the following five research priority areas: (1) postharvest physiology ./quality, (2) resistance, epidemiology, and control, (3) standardization of variety evaluations and data accumulation, (4) removal and disposal of plastic mulch, and (5) disease forecast systems.

III. New Business. It was decided at the SAAS Meeting that we should invite all interested people (national and international) to become involved with our group. Once we get the Web site working we want to enter their personal data into the system. We will have a search engine so that a person can find an expert in watermelon culture, fertility, plastic mulch, postharvest problems, foliar diseases, or soilborne diseases, etc. This information should provide a very nice service to research and extension personnel to find needed information. We do not intend to try to duplicate information that is covered on other Web Pages. Hopefully, we will have the system up and running before long.

IV. Next Meeting. the 20th Annual Watermelon Research and Development Working Group meeting will be from 1"00 to 5:00 p.m. on Sunday, 30 January 2000, in Lexington, Kentucky.

V. Special thanks. The WRDWG would like to extend a special thanks to Dr. Tom Williams of Novartis Seeds, Inc. for sponsoring refreshments at this year;s annual meeting. We appreciate your support! We would also like to thank the past refreshment sponsors Sunseeds (1998), Barham Seeds (1997), American SunMelon (1996), Willhite Seeds (1995), Asgrow Seed Company (1994), and American SunMelon (1993).

For more WRDWG information, please contact Dr., benny D. Bruton [], US Department of Agriculture, Agricultural Research service, Lane, Oklahoma 74555. (Ph.: 580/889-7395; Fax:580/889-5783.

Cucurbit Crop Germplasm Committee (CCGC) Update

J.D. McCreight (Chair)

The cucurbit Crop Germplasm Committee met in Asilomar, California in conjunction with Cucurbitaceae '98 on December 3, 1998.

Kathy Reitsma, Curator of cucurbits, North Central Regional Plant Introduction Station, Ames, Iowa provided an update on germplasm activities. She stated that the budget remains tight, and that they are barely keeping up with the workload. A backlog of cucurbit characterization data at Ames awaits entry into GRIN, due in part to the lack of a computer specialist to oversee data entry. Data in the Prime-based GRIN system are not available in the Oracle-based system. Mark Bohning [] commented that PCGRIN is difficult to use, and that perhaps the GRIN Database Management Unit could improve the data downloading process.

Henry Munger suggested inclusion of a database field in GRIN for useful traits. Laura Merrick stated that descriptors were already in GRIN. Dr. Munger wanted accessions of value to be marked for high priority for maintenance. Ms. Reitsma stated that accessions are regenerated if seed is in short supply, or if the accession has been requested. She requested that germplasm users return remnants of accessions that have low numbers of seeds.

Laura Merrick, Iowa State University, commented that the classification of Cucumis accessions be made easier for users to find and name them. Ms. Reistma suggested that John Wiersma (USDA-REE-ARS-BA-PSI-SB&M LAB, Bioscience RM 330, 10300 Baltimore Blvd, Beltsville, MD 20705-0000), be contacted for improvements. Deena Decker-Walters and Molly Jahn requested that botanical variety and subspecies be included in GRIN. Kathy Reitsma and Bob Jarret are reclassifying accessions to proper species.

Charles Block, Plant Pathologist, RPIS, Ames, reported the occurrence on Cucumis melo accessions of a bacterial leaf disease that was similar to watermelon fruit blotch incited by Acidovorax acenae spp. cirulli.

Bob Jarret, Curator for Citrullus, Cucurbita and other cucurbits, reported on the germplasm activities at the Southern RPIS, Griffin, Georgia. He stated that a low percentage of accessions are available, and that many stocks are unavailable. The USDA, ARS station at Byron is now being used for caged seed increases. ARS facilities at Parlier, California, and Miami, Florida, have also been used for seed increases. Dr. Jarret stated that limited funds for germplasm characterization and increase warrant the use of a designated core collection. Claude thomas, USDA, ARS, Charleston, South Carolina, made a motion that the CCGC write the USDA-ARS National Program Staff about the poor funding for cucurbit increases at Griffin. This was seco0ndd and unanimously passed.

Richard Robinson, New York Experiment Station, Geneva, provided an update on the Northeastern RPIS, Geneva, new York. Larry Robertson was hired to replace Jim McGerson who resigned in 1998. The Geneva collection contains 975 PI accessions of ca. 16 species of cucurbits, plus 132 accessions yet to be numbered. Dr. Robinson expressed concern about the small number (9) of Cucurbita accessions increased in 1998 relative to the number of accessions with low germination (5 accessions 60%), or no recent germination test (480). Nine 12 x 48 ft. cages had been purchased for field increases of cucurbits using honeybees in lieu of hand-pollination.

Michel Pitrat, INRA, Montfavet, stated that France has 100 USDA accessions in its melon collection of 800 total accessions, and that seeds are increased by seed companies for the collection each year.

Two proposals for FY 1999 were submitted after the deadline for cucurbit germplasm evaluation. A proposal from Professor Poostchi, to translate and publish in book form descriptions of cucurbits of Iran was discussed. Seeds of the described accessions would be submitted to the US-NPGS.

The Wehner-McCreight expedition to Zimbabwe is being planned for April 1999 for collection of Cucumis and Citrullus.

Todd Wehner suggested that all crop evaluation priority lists be revised to account for the work that has been completed in the past few years.

New Books of Interest to CGC Members

Cucurbitaceae '98: Evaluation and Enhancement of Cucurbit Germplasm

J.D. McCreight (ed.)

Paperback (8.5" x 11'
ISBN 0-9615027-9-7

List: $35 + shipping (CGC and/or ASHS members

$45 + shipping (non-members)

The proceedings from Cucurbitaceae '98, which was held in December 1998 at the Asilomar Conference Center in Pacific Grove, California. The volume contains more than 60 papers presented at the meeting in the areas of germplasm resources, genetics, breeding, pathology, entomology and production. Advance your knowledge on the collection, preservation, characterization evaluation, and enhancement of cucurbit germplasm. To order by credit card, contact ASHS Press at 703/836-2418; fax the ASHS Press Print-and-Fax Order Form (obtainable from to 703/836-6838 or email

20th Century Bioscience: Professor O.J. Eigsti and the Seedless Watermelon

John H. Woodburn

"The life story of O.J. Eigsti and the seedless watermelon is interwoven with the evolution of genetics, horticulture, and education throughout the twentieth century." This biography describes the highs and lows of being a farmer, scientist, and teacher throughout much of the century. From his first entry level position at the Carnegie Institution of Washington at cold Spring Harbor, to full professorships at the University of oklahoma, Northwestern and Chicago State, this informative and entertaining biography follows the life and career of Prof. O.J.Eigsti from farm boy to highly successful botanist and educator, searching for the secret to a commercially successful seedless watermelon. The book can be ordered directly from Pentland Press, Inc., 5122 Bur Oak Circle, Raleigh, NC 27612 USA. (Ph.: 800/948-2786; fax: 919/781-9042.) Please inquire concerning shipping charges.

Upcoming Meetings of Interest to Cucurbit Researchers

Pickle Packers Fall Business Conference
27-29 October 1999
Opryland Hotel, Nashville, Tennessee
Pickle Packers Intl.
(630) 58-8950
Watermelon Research and Development Group
30 January 2000
Lexington, Kentucky
Benny D. Bruton
(580) 889-7395

Cucurbitaceae 2000


19-23 March 2000
Ma'ale Hachamisha Resort & Convention Center, Israel
Nurit Katzir
Cucurbit Genetics Cooperative

28 July 2000


Minneapolis, Minnesota
Timothy J. Ng
(301) 405-4345
?? July 2000
Orlando, Florida
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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 15 December, 2009