Cucurbit Genetics Cooperative Report 17:6-11 (article 2) 1994
J.E. Staub
Vegetable Crops Research, USDA/ARS, Department of Horticulture, University of Wisconsin-Madison, WI 53706
James McCreight and I have recently returned from a plant collection trip to India (McCreight and Staub, 1993). This collection trip increased the number of accessions in each of the U.S. cucumber and melon collections by approximately 20%. These accessions are currently being increased at the Regional plant Introduction Station, Ames, Iowa. After their increase these accessions will be further evaluated for various morphological and biochemical polymorphisms.
Although collection and evaluation efforts such as these are important for maintaining an adequate level of genetic diversity in these crops, the management of the collections will be increasingly difficult given the projected limited resources. It has been the continued desire of the U.S. Plant Introduction System to devise efficient management strategies which enable the use of a wide range of diverse materials in collections. This has led to proposals for the development of core collections. A core collection should not be considered a separate collection, but rather a subset of an existing collection. The purpose of a core collection is to facilitate use and provide efficient access to the potential variation that exists in the whole collection (Brown 1989a,b; Frankel and Brown, 1984).
It has been suggested in discussions at U.S. Cucurbit Crop Advisory Committee meetings and other U.S. National meetings on germplasm diversity (e.g. meetings of the Genetics and Germplasm Working Group, American Society for Horticultural Science) that the cucumber collection is small and not well characterized. This has led to a general consensus that cucumber would not lend itself to the establishment of a core collection. However, based on the fact that the cucumber collection has now been evaluated for various disease resistances, cold. drought and heat tolerance, yield performance, various morphological characteristics, and biochemical variation, I submit that further discussion on this subject is warranted.
In this edition of the Cucurbit Genetics Cooperative Report, I reported the results of a survey intended to ascertain the general feeling among U.S. cucumber researchers regarding the potential need of a cucumber core collection. This survey suggested that there is a desire and need for continued discussion regarding the Core Concept as it might apply to cucumber. In an effort to stimulate such a discussion, in 1993 I requested that the 24 respondents of the original survey provide me with more information regarding their impressions on which cultigens (adapted or unadapted inbreds, hybrids, populations) might be used to construct a core collection in cucumber if it were deemed appropriate. The results of this survey are presented in Table 1.
for a core collection to be effective it must mirror the genetic diversity found in the whole collection of which it is a subset (National Research Council, 1991). Typically, core collections are considered to house no more than 10% of the collection from which they are drawn (Brown, 1989a,b; Frankel and Brown, 1984). I suggest that further discussion as to the potential establishment of a core collection for cucumber be based on these two guiding principles (i.e., potential diversity and size). It is possible that, based on the present genetic information available, cucumber subsets might be constructed which would provide researchers with accessions which, taken collectively, possess genetic diversity for specific characteristics (e.g.,disease resistance and environmental stress tolerance).
Table 1. Cultigen PIs which warrant consideration for possible inclusion in a core collection for cucumber.
Cultigen/PI |
Reason for inclusion |
| 163213 | anthracnose resistance |
| 163217 | anthracnose resistance |
| 164743 | low reducing sugar concentration |
| 165499 | disease resistance |
| 165509 | disease resistance |
| 173889 | disease resistance Bt gene |
| 175120 | multiple tolerance or resistance |
| 175686 | low soluble solids |
| 175697 | fruit pH of 5.9 |
| 179676 | multiple disease resistance, downy mildew, good fruit type |
| 181755 | cold germination |
| 183967 | multiple & sequential fruiting character, hardwickii |
| 188749 | triazine tolerance |
| 188807 | vigor,wilt and multiple disease resistance, triazine tolerance |
| 197085 | multiple disease resistance |
| 197087 | anthracnose, downy, powdery mildew resistance, India |
| 197088 | multiple disease resistance |
| 200815 | wilt resistance |
| 200818 | wilt resistance, bacterial wilt resistance |
| 211983 | cold germination |
| 211984 | ambien tolerance |
| 212233 | powdery mildew resistance |
| 212599 | gold germination |
| 220791 | cold germination |
| 220860 | multiple disease resistance, gynoecious character |
| 222243 | cold germination |
| 227207 | multiple disease resistance |
| 227208 | multiple disease resistance |
| 234517 | powdery mildew resistance |
| 249561 | disease resistance |
| 249562 | disease resistance |
| 257586 | low soluble solids |
| 263079 | cold germination |
| 064688 | ambien tolerance, low soluble solids |
| 267087 | cold germination |
| 267746 | biochemical variation |
| 267747 | Alko bush cucumber |
| 267942 | multiple disease resistance |
| 269480 | biochemical variation |
| 275411 | fruit pH of 6.9 |
| 279465 | disease resistance, angular leaf spot,. ‘Natsufushinari’ |
| 283902 | low soluble solids |
| 285603 | low reducint sugar concentration |
| 288238 | powdery mildew resistance; comes from ‘Yomahi’ |
| 306179 | cold germination |
| 308915 | dwarf (short internode) |
| 308916 | dwarf (short internode) |
| 321006 | disease resistance |
| 321007 | disease resistance |
| 321008 | disease resistance |
| 321011 | ‘Taichung Mou Gua’, virus resistance |
| 351139 | hermaphroditic |
| 351140 | hermaphroditic |
| 355052 | best alpar from Israel |
| 356809 | hermaphroditic |
| 360939 | ‘kora’, European pickle, prolific |
| 369717 | androeious |
| 372893 | bitterfree |
| 390244 | atrazine tolerance390258 |
| 390258 | powdery mildew resistance |
| 390260 | triazine tolerance |
| 400270 | ‘Kyoto Three Feet’ |
| 418962 | powdery mildew resistance, downy mildew resistance |
| 418964 | powdery mildew resistance, downy mildew resistance |
| 418989 | cold tolerant |
| 419009 | cold tolerant |
| 419017 | heat resistant |
| 426169 | powdery mildew resistance |
| 426170 | powdery mildew resistance |
| 432860 | biochemical variation |
| 432895 | powdery mildew resistance |
| 451975 | powdery mildew resistance, downy mildew resistance |
| 451976 | powdery mildew resistance, downy mildew resistance |
| 458845 | biochemical |
| Addis | disease resistance, long pickle |
| Arkansas Little Leaf | sequential fruiting, multiple branching |
| ASHE | |
| Ashley | classic variety, old slicer |
| Chinese Long | CMV, PRV, WMV, ZYMV resistance |
| Chipper | disease resistance, fruit quality, fruit shape, old pickle |
| Clinton | pickle, dark green fruit, small seed cavity, disease resistance |
| Coolgreen | Beit Alpha |
| Delcrow | late slicer |
| Dual | long pickle |
| Delikatess | Germany |
| Galaxy | old pickle |
| Germin | Clemson University |
| Gy 54/57 | disease resistance, gynoecious slicing hybrid parent, GCA* |
| Gyn 3 | disease resistance, gynoecious |
| Gyn 14 | disease resistance, gynoecious character, GCA |
| Gyn 4 | disease resistance, high yielding |
| Gyn 5 | disease resistance |
| Gyn 57u | gynoecious slicer |
| Hokus | |
| Homegreen #2 | GSB resistant ** |
| Lemon | genes m, l, and yg |
| M21 | disease resistance, determinate gene, fruit quality, GCA, dwarf |
| M27 | disease resistance, dwarf |
| Marketmore | slicer, non-bitter, uniform color, classic for type & disease resistance |
| Marketmore 76 | classic for type & disease resistance, northern slicer |
| Marketmore 76F | disease resistance |
| Marketmore 80F | disease resistance, gynoecious slicer |
| Marketmore 83 | slicer representative |
| Marketmore 85 | dwarf slicer |
| Marketmore 87 | disease resistance |
| Marketmore 88 | disease resistance, slicer |
| Marketer | Important sw check; induced resistance, classic variety |
| Minn. Dwarf XII | de |
| Model | classic variety |
| MSU 713-5 | disease resistance |
| National pickling | historically important |
| Ohio MR 17 | historically important |
| Palmetto | Clemson University |
| Pixie | Clemson University, bloater susceptible |
| Poinsett | dm resistance; classic for type & disease resistance |
| Poinsett 76 | classic for type & disease resistance, southern slicer |
| Poinsett 83F | gynoecious slicer |
| Poinsett 87 | disease resistance & scab, CMV and TLS*** |
| Poinsett 88 | disease resistance, slicer |
| Polaris | dm resistance, Clemson Univ. |
| Regal | high yield, long pickle type |
| Slice | GSB resistance |
| SMR 18 | classic variety, disease resistance, vigor, cold tolerance, GCA |
| Spacemaster | slicer, determinate vine, dwarf slicer |
| Spartan Salad | PMR and some DMR and CMV |
| Straight 8 | old susceptible slicer |
| Stono | Clemson University |
| Summit | old southern pickle |
| Sumter | old southern pickle |
| Supergreen-butalpha | Beit Alpha type |
| Tablegreen 65 | mosaic resistance |
| Tablegreen 72 | old slicer |
| Telegraph | parthenocarpic |
| Tiny dill | dwarf pickle |
| TMG-1 | CMV and virus resistance |
| Tokyo Long Green | virus resistance |
| W1082HP | hermaphrodite, parthenocarpic, pickle |
| W2757 | multiple disease resistance pick;e; combining PMR with TLS |
| Wautoma | northern pickle |
| White wonder | white slicer |
| Yomaki | homozygous F/F |
| Zeppelin | schalgurken |
* GCA – General combining ability for yield as measured by F1 performance.
** GSB = Gummy stem blight resistance
*** TLS = Target leaf spot resistance
Literature Cited
- Brown, A.H.D. 1989a. The case for core collections. p. 136-156. In: A.H.D. Brown, O.H. Frankel, D.R. Marshall, and J.T. Williams (ed.). The Uses of Plant Genetic Resources. Cambridge University Press, New York.
- Brown, A.H.D. 1989b. Core collections: A practical approach to genetic resources management. Genome 31:818-824.
- Frankel, O.H., and A.H.D. Brown. 1984. Plant genetic resources today: a critical appraisal. P. 249-257. IOn: J.W. Holden and J.T. Williams (ed.). Crop Genetic Resources: Conservation and Evaluation. Allen and Unwin, London.
- McCreight H.D. and J.E. Staub. 1993. Indo-US Cucumis germplasm expedition. HortScience 28:467. (Abstract)
- National REsearch Council. 1991. Prescription for effectiveness. p. 124-126. In: Board on Agriculture, National Academy of Sciences. Managing Global Genetic Resources: The U.S. National Plant Germplasm System. National Academy Press, Washington, DC.