Cucurbit Genetics Cooperative
Other Crop Genetics Cooperatives
Home About Membership Reports Gene Lists Conferences Links Search NCSU
Cucurbit Genetics Cooperative Report 21: iii-v (article 0) 1998

Cucurbitaceae '98: Evaluation & Enhancement of Germplasm

"Cucurbitaceae '98: Evaluation and Enhancement of Cucurbit Germplasm" will be held from 30 November to 4 December 1998 at the Asilomar Conference Center in Pacific Grove, California, USA. The meeting is sponsored by the American Society for Horticultural Science (ASHS) and the USDA Agricultural Research Service. Besides ASHS and USDA/ARS, conveners include the Cucurbit Genetics Cooperative and The Cucurbit Network.

There will be sessions on Germplasm Resources, Entomology, Pathology, Industry, Breeding, Genetics, and Mapping and Markers. In addition to the research and discussion sessions, there will be meetings of the Cucurbit Crop Germplasm Committee, the National Melon Research Group, the Cucurbit Genetics Cooperative, the Watermelon Research and Development Group, the Squash Breeders, the National Cucumber Conference, and the Pickling Cucumber Improvement Committee.

The conference facility, Asilomar, is a U.S. National Historic Landmark located on 44 hectares (107 acres) of pristine forest, dunes and beach in Pacific Grove. It offers on-site recreational facilities, such as a heated pool, volleyball courts, and walking trails. Guests are free to walk myriad forest paths, miles of nearby beach, and the adjacent boardwalk that spans a sand dune restoration project. (The project ensures the preservation of several rare and endangered species of plants.)

Social activities will include a "Taste of California" Reception, a Networking/Social Gathering, a Monterey Bay Aquarium Excursion, and a Special farewell Luncheon. Optional Tours will be available to Big Sur and to "Steinbeck Country."

The early registration deadline is 26 October 1998. On-site registration will also be available., A full brochure, including information on fees and payment, housing, meal service, and driving directions from San Francisco or Los Angeles, can be obtained by writing to:

Cucurbitaceae '98, 600Cameron Street, Alexandria, VA, 22314-2562, USA (Fax: 703.836.2024

Alternately, information can be downloaded from the web at We hope to see you there!


From the CGC Coordinating Committee: The Call for Papers for the 1998 Report (CGC Report No. 21) will be mailed in September 1997. Papers should be submitted to the respective Coordinating Committee members by 31 January 1998, although late submissions may be considered if received prior to our processing deadline. The Report will be published by June/July 1998. 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.

1997 Annual CGC Business Meeting

The 21st annual CGC Annual Business Meeting was held at on 25 July 1997, in Salt Lake City, Utah, in conjunction with the 94th Annual Conference of the American Society for Horticultural Science (ASHS). Twenty-six members and friends of CGC were in attendance.

Tim Ng opened the meeting by pointing out that the original organizational meeting for CGC was also held in Salt Lake City, at the 1977 ASHS meeting, and that CGC has grown considerably in the past 20 years. Updates on the CGC membership, reports and finances were then presented. Tim mentioned that CGC Report No, 20 (1977) was delivered to the printer on July 10, and that copies should be available and sent to CGC members within a few days. The timetable for soliciting reports for CGC Report No.21 (1998) was briefly mentioned. Also, for the first time CGC members will be able to submit their manuscripts via encoded files on the Internet to the appropriate Coordinating Committee member.

Tim next gave an update on the CGC web page. Although CGC has decided not to make complete copies of CGC Reports less five years old available on the web, Tim is listing the table of contents and coding a few papers from each new issue for the website as an inducement for prospective new CGC members to join. Meanwhile, the volunteer digitization and OCR effort for back issues was going slowly, and two issues had been placed on the web in pdf format just to expedite the process. Priorities are now being given to back issues which are out of stock, or for which only a few copies are left in inventory.

CGC Coordinating Committee members serve 10-year terms, and J. Brent Loy (Univ. New Hampshire) rotated off in 1997 as the Coordinating Committee member for Cucurbita spp. Linda Wessel-Beaver (Univ. Puerto Rico) was elected as the new CGC Coordinating Committee member for Cucurbita. Thanks, Brent, and congratulations, Linda!

Harry Paris' request to change Rule #3 of the CGC Gene Nomenclature for the Cucurbitaceae (first presented at the 1996 CGC Business Meeting) was discussed further. Harry felt that since no standard or normal genotype has been established for any species of the Cucurbitaceae, it is inappropriate for us to automatically use the symbol "+" to indicate the "wild" type. Rather, we should change our rules to be consistent with those in the Glossary of Genetics and Cytogenetics (R, Rieger et al., 1976) whereby the recessive allele is entirely in lower case and the dominant allele is capitalized. Dick Robinson pointed out that the cucurbit gene rules were first proposed in 1976 by a committee appointed by ASHS, and were based on the gene rules for the Tomato Genetics Cooperative. Prior to the establishment of these rules, cucurbit gene nomenclature was confusing, with incorrect gene symbols, duplicate symbols and names, multiple symbols and names, and unassigned symbols commonly found in the scientific literature. These and other discrepancies were subsequently eliminated through the work of the Cucurbit Gene List Committee and CGC. Dick felt that with the current proposal and other proposals that may arise to change the gene rules, and CGC should adopt whatever rules most members prefer. He also pointed out, however, that there are times when using the "+" designation might be convenient, such as with multiple gene stock studies where using the "+" would simplify the genotype discussion.

After much discussion, the members decided to change Rule 3 to conform with Glossary of Genetics and Cytogenetics nomenclature. This will be reflected in future Gene Lists and Gene Nomenclature Rules in the CGC Report. However, the members also thought that researchers should be able to use whatever system the preferred for their own research reports, such as the "+" designation, as long as the usage is consistent and clear throughout the article. This will also be made evident in the revised CGC Gene Nomenclature rules.

The proposal of having CGC compile a list of cloned genes of the Cucurbitaceae was again discussed. A committee consisting of Gary Thompson, Mike Havey and Rebecca Grumet (Chair) was asked to look further into the feasibility and need for the project.

Upcoming meetings were announced, such as those for the PCIC/PPI/CCCGC joint meeting (Las Vegas, October 1997) and Cucurbitaceae '98 (California, December 1998). The next GEG meeting will be held in July 1998 in Charlotte, NC, in conjunction with the 95th ASHS Conference.

Under New Business, Todd Wehner asked whether we would be willing to pay a small "affiliate's fee" to ASHS as compensation for their scheduling the CG meeting in conjunction with their Annual Conference. Tim mentioned that CGC was a small, non-profit organization run "on a shoestring," and that any additional expenses would have to be passed on to the membership. Several members remarked that if an "affiliate's fee" were to be charged, that perhaps we shouldn't try to be scheduled in the ASHS program, but should just show up anyway and try to find an empty room or meet in one of the local establishments in the conference town. After further discussion, it was decided not to entertain the idea of paying a fee any further.

As there wa no further business, and the meeting was adjourned.

1998 Annual CGC Business Meeting

Tim Ng, Chair

The 22nd annual CGC Business Meeting was held on 15 July 1998 in charlotte, North Carolina, in conjunction with the 95th Annual Conference for the American Society for Horticulture Science (ASHS). Despite ASHS;s scheduling of a cucurbit production research session and a cucurbit seed physiology presentation concurrent with the CGC meeting, 17 members and friends of CGC were in attendance.

After introductions, Tim Ng began the meeting by presenting updates on CGC membership, reports, and finances. He also mentioned that CGC Report No. 12 (1998) would be delayed this year because of unexpected demands on his time, including an earlier than usual ASHS meeting. He hoped to have it completed by the end of July. The Call for Papers for CGC Report No. 22 (1999) will be sent some time in September 1998, with a suggested deadline of 30 January 1999 for submissions. With the millennium approaching, Tim also mentioned that the computers and software he used for CGC were all Y2K-compliant.

The issue of curating the cucurbit mutant collection was brought up. Of particular concern was the watermelon mutant collection, with one curator no longer at his former company (although the seed were) and the other curator recently discovering that some of his seedlots were contaminated with the watermelon fruit blotch organism, Several alternatives were discussed, including possibly having the USDA PI station handle the curation. However, it was pointed out that some of these mutants are difficult to cultivate and maintain and that standard PI procedures for seed increases might no be sufficient for these mutants. After further discussion, it was decided that we should encourage Todd Wehner to review his request for funding for a cucurbit gene center and resubmit it to the CCGC.

Jim McCreight provided an update for Cucurbitaceae '98 meeting. Brochures containing the second announcement were being distributed at the ASHS meeting. Tim mentioned that the ASHS website had been updated in the past week with the information also, and that he had provided a link from the CGC page to the ASHS information on Cucurbitaceae '98. (Editor's note: further information on cucurbitaceae '98 can be found elsewhere in this CGC Report.)

Tim gave an update on the impact of the Internet on CGC. At least a dozen new members had joined after finding CGC on the web. As for the "digitization of back issues" project, Todd Wehner has completed the OCR work on Reports 1 and 2. Tom Andres and Jim McCreight are nearly finished with Reports 3 and 4, respectively. Bill Rhodes has completed OCR work on Report 5. Rebecca Brown and Jeff Adelberg are still working on their reports. Bruce Carle volunteered to tackle Report 8, Linda Wessel-Beaver Report 9, Todd Wehner Report 10, Jim McCreight Report 11 and Jack Staub Report 12. They will be sent the originals for each of these reports.

There was no further business, and the meeting was adjourned.

Cucurbit Crops Germplasm Committee Update

James D. McCreight, Chair

The Cucurbit Crops Germplasm Committee (CCGC) met in Las Vegas, Nevada, on 30 October 1997 in conjunction with Pickle Packers International (PPI) and the Pickling Cucumber Improvement Committee (PCIC).

Alan Stoner, Director, Plant Genetic Resources Laboratory, reported that PCGRIN will be made available to countries for management of local germplasm collections. PIGRI is translating the documents into Spanish and other languages. Also, the General Accounting Office (GAO) survey of the national Plant Germplasm System (NPGS) is complete and will be sent to CGC chairs. It is also available on the web at (request report GAO/RCED-98-20). The study was initiated by GAO, and the highest marks were given to GRIN system. Suggestions for improvements to GRIN need to be sent to CCGC to permit them to make the needed changes.

Alan also reported that images are now available on GRIN. Todd Wehner reported that he sent 35 mm color slides of Luffa fruits to Griffin for their database. A proposal was made by Todd to include photos of the cucumber collection as well. Ames has scanners for images, but it has been used heavily by the maize project.

Kathy Reitsma, Cucumis curator, reported that the Ames Plant Introducti8on collection has 3,054 melons, 1,350 cucumber, 347 wild, and 1006 squash accessions, with 34% to 80% available,and 6% to 55% backed up at NSSL. Evaluation data ready to be loaded includes downy mildew of melon (Claude Thomas) and GSB in melon and squash (Molly Kyle). GRIN passport information continues to be updated from old reports and seed packets. The Committee voted to have the three Bryona accessions transferred to Griffin. Charles Block (Ames) reported that original seeds of melon and squash are being tested by ELISA for squash mosaic virus. Accessions sent directly to NSSL may not be included in active collections, and the accessions at NSSL are available in multiple sets. Grow-outs need to be made to identify which accession is the most appropriate to include of the duplicate sets.

Jack Staub learned on a visit to India in September that many of the seeds that were collected in 1992 (Staub and McCreight, Cucumis expedition) had been misplaced or had a reduced level of germination. Thus, some of the accessions collected that year are only available 9n the USA.

Germplasm, Evaluation. Dave Wolff is completing his Monosporacus resistance evaluation in melon. Don Hopkins is working on fruit blotch resistance in watermelon. Mark Bohning is developing procedures for tracking entry of evaluations into GRIN.

Germplasm collection. Bob Jarret would like to make a list of collection sites to visit in priority order. Allan Stoner would like to see planned exploration proposals so prioritize system,-wide crops. Ten proposals were forwarded for review. Collection in India is now easier, and should be pursued.

Germplasm exchange. Exchange are requested and often are sent. The Vavilov Institute in Russia is on the web, and accessible through the GRIN web site. The Vavilov Institute is being supported by Russia, but additional support has been requested from other countries, including the USA. Their records are being computerized, and seeds are being increased. IPGRI is involved. Other exchanges needed are: Beijing, Poland, Czech Republic. Although Russia and eastern Europe are exchanging, some countries have restrictions on germplasm use.

Gene Stocks. Although tomato gene stocks are maintained formally by USDA through the Charles Rick Tomato Gene Stock Center, (University of California, Davis), proposals by Dick Robinson and Todd Wehner for a cucurbit gene stock center have not been funded. Gene mutants are difficult to maintain, and need to be done separately from RPIS increases. A gene stock center proposal could be developed for submission in 1998.

The cucumber and watermelon subcommittee reports were updated, but the squash and melon reports were not.

18th Annual Meeting of the Watermelon Research and Development Group

Ray D. Martin, Past Chairman

The Watermelon Research and Development Group (WMRG) met in Little Rock, AR, on Sunday, 1 February, 1998, for its 18th annual meeting. The meeting was held at the Robinson Center in conjunction with The Southern Association of Agricultural Scientists (S.A.A.S.), the Southern Region; American Society for Horticultural Sciences, (SR:ASHS) and the Southern Division: American Phytopathological Society (SD:APS). This was one of the best attended meetings in a long time with a lot of discussion. In addition, Mr. William Watson, Executive Director of the National Watermelon Promotion Board was present and gave an update on the activities of the Board and their research support program. And lastly, Dr. Benny Bruton, was elected as the new Chairman for WMRG. Benny is a plant pathologist with the ARS-USDA Laboratory in Lane, OK.

I. Research Updates. A number of research presentations were made by the scientists present. George Boyhan, University of Georgia, Statesboro, GA, [] talked about developing YMV resistant watermelon cultivars. George has been evaluating different Eqisi and Egun types for resistance to ZYMV and WMV. One of the most promising lines has been an AU-Producer x Egun cross. Several back crosses have been made with good results. The fruit is not yet uniform in color but it does have good resistance to both ZYMV and WMV. They are still several years from the finished product. Charlie Main and Gerald Holmes, North Carolina State University, Raleigh, NC, talked about long distance movement of downy mildew spores. Charlie and Gerald presented the computer model forecast system for tobacco blue mold (downy mildew) as a potential model for use in cucurbit diseases. The model is based point source of inoculum, wind speed and directions, and rain events. A network of spotters in various states report when the disease occurs in their area, From there, the model will predict when and where the next outbreak will occur. A good discussion took place about the potential for developing a similar model for DM of cucurbits. For more information see the Blue Mold Home page at

Don Maynard, University of Florida, Bradenton, FL, [], discussed watermelon fruit defects. Don addressed the topic of fruit maladies of unknown cause. The first was a ring spot symptom on fruit nd it was a consensus of the group that it was probably caused by papaya ring spot virus. The second symptom was a rind necrosis. There appeared to be varietal differences. It appeared similar to the bacterial rind necrosis but there was not a group consensus. The last major malady was hollow heart. Don asked the questions "When does it first begin to develop in the fruit? Is there a genetic basis for it occurring? Are seedless more prone than seeded varieties? Is it environmentally induced?". It was noted that a fluorescent microscopy technique can detect hollow heart when it is only 2-3 mm in size. Dan Egel, Purdue University, SW Purdue Agricultural Center, Vincennes, IN, [egel@purdue.,edu] talked about fungicide application technology for melons. Dan reported on a series of tests in which he evaluated spray pressure and nozzle type for efficacy in spraying melons for Alternaria blight. His data indicated that there were no difference in effectiveness between flat fan and hollow cone nozzles at either 30, 60, or 90 psi. At lighter pressures, differences may be evident.

Bruce Carle, University of Florida, Central Florida AREC, Leesburg, FL [], discussed new directions in watermelon breeding in Florida. Bruce is a new faculty member specializing in cucurbit breeding. His main research thrust is on improving disease resistance in diploid watermelons (Fusarium wilt race 2, ZYMV, WMV 2, fruit blotch, and anthracnose). He is working toward pyramiding resistance genes. A second emphasis is improving in vitro tetraploidy in seedless varieties. Bruce also announced that the watermelon breeding program will move to the Apopka Station as the Leesburg Station will be closing down. Dr. Todd Wehner, North Carolina State University, Raleigh, North Carolina [todd_wehner@ncsu,edu], gave an overview of the watermelon breeding program at N.C. State. Todd has renewed Warren Henderson's program on studying the inheritance of the inhibitor gene for yellow flesh. He is also working on disease resistance to gummy stem blight. He has identified a high level os resistance to this disease in PI 189225. He is trying to correlate results of seedling disease assays with mature plants in the field. Thus far, seedlings that appear resistant in the greenhouse are susceptible in the field. Todd is screening a number of accessions from the germplasm collection including 51 Citrullus accessions from China and 25 from South Africa.

Joe Norton, Auburn University, Auburn, AL, reported on the work of Dr. Fenny Dane in investigating molecular tagging for identifying resistance genes to Fusarium wilt and gummy stem blight and also the use of AFLPs and PCR for variety identification. Joe also reported that much of the honey bee population has been destroyed by the predatory mite infestation. Tony Keinath, Clemson University, Clemson, SC [], discussed PCR detection of Didymella byroniae. Tony has developed specific PCR RAPD primers that can distinguish between D. bryoniae and Phoma, P. exuda, produces a 450 bp band that can be used for identification. Thus farm thus species has only been found in New York.

Benny Bruton, USDA-ARS, Lane, OK, [] gave an update on yellow vine disease Using primers for the 16S RBA of prokaryotes, they have identified a 640 bp fragment that is amplified from symptomatic plant tissue but is not amplified from healthy tissue. PCR has been able to detect this fragment from all parts of the plant. Also, transmission electron microscopy shows bacteria-like organisms in the phloem tissue of symptomatic plant tissue, but not in healthy tissue. There is also a distinct phloem necrosis associated with this malady.

II. News From the National Watermelon Promotion Board. William Watson, Executive Director, NWPB, Orlando, Fl, [], announced that the research program sponsored by the NWPB had an increase in funding this year,. IN 1997 there was $12,500 available to support research. This year, there was $40,000. This is a big increase and shows the support that NWPB has for watermelon research. Twenty-one proposal were received this year as opposed to 12 proposals last year. THe NWPB's web site won a first place national award from the National Agriculture Marketing Association (NAMA). This is a nation-wide competition. They also won several other awards for marketing, as well as "best of show" for their Media Kit. Congratulations.

III. New Business. George Boyhan, University of Georgia, agreed to take the lead in setting up a web site for our group. Items that could be included on the site would be meeting summaries, dates, etc.; mailing addresses and e-mail lists; upcoming events; research notes, and links to many other watermelon related topics. Please send your comments to George. Also, we were asked by the Southern Region: American Society for Horticulture Sciences to consider changing our meeting time from Sunday afternoon to something different because of perceived conflicts with other events. A vote was taken and it was agreed that a Sunday afternoon time was good and we would not change at this time. The meeting time for the WMRG will remain Sunday at 1 p.m.

IV. New WMRG Chairman, Benny Bruton, Plant Pathologist with the USDA-ARS in Lane, OK, was duly elected the new chairman of the Watermelon Research Group. Benny is a long-time participant of the group and conducts research on soilborne disease of melons and watermelons. Benny officially took over the chairmanship at the close of this meeting.

V. Upcoming Meetings. The 19th Annual Meeting of the Watermelon Research and Development Group will be 30 January 1999 in Memphis, TN.

Upcoming Meetings of Interest to Cucurbit Researchers


Pickle Packers Fall Business Conference
14-16 October 1998
Sheridan Center, Toronto, Ontario, Canada

Pickle Packers Intl.
(630) 584-8950

Cucurbitaceae '98
30 November - 4 December 1998
Asilomar Conference Center, Pacific Grove, California

James D. McCreight
(831) 755-2684

Note: the following groups will also meet at this conference: Cucurbit Crop Germplasm Committee, National Melon Research Group, Cucurbit Genetics Cooperative, Watermelon Research & Development Group, Squash Breeders, National Cucumber Conference, Pickling Cucumber Improvement Committee

Watermelon Research and Development Group
30 January 1999
Memphis, Tennesse

Benny D. Bruton
(404) 889-7395

Cucurbit Genetics Cooperative
July 1999
Minneapolis, Minnesota

Timothy J. Ng
(301) 405-4345

Pickling Cucumber Improvement Committee
27-29 October 1999
Opryland Hotel, Nashville, Tennessee

Jack E. Staub
(608) 262-0028

Home About Membership Reports Gene Lists Conferences Links Search NCSU
Department of Horticultural Science Box 7609North Carolina State UniversityRaleigh, NC 27695-7609919-515-5363
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