Practical Considerations for Increasing Seed Samples of Wild Species

  • Barbara C. HellierEmail author


Wild species and crop wild relative samples whether for a gene bank or restoration need to be increased or replenished if original sample sizes are small, quantities have decreased with distribution and use, or viability has declined. An ideal source for fresh seed of wild species is from the original collection population. If re-collection is not possible, then ex situ increase is needed. The goal for seed increase is to maintain the genetic integrity of the original sample and produce high-quality seed. This is a challenge when growing crop species and even more of a challenge for wild species because of heterogeneity within accessions, increased seed dormancy, increased seed shattering, low seed production, indeterminant flowering and seed set, and little information on pollination biology or cultural needs. Preventing genetic drift and natural selection are two key components to maintaining genetic diversity during seed increase. A large effective population in increase plots, balanced sampling, and breaking seed dormancy are important for limiting genetic drift. Providing appropriate pollination and cultural conditions for wild species is important to impede natural selection. Seed growers can glean clues to breaking seed dormancy and the cultural needs of a species from accession passport data. Diligent attention to detail must be taken to prevent contamination between and among accessions being increased and to prevent physical damage to the seed produced through all the steps of seed production.


Seed dormancy Genetic drift Elymus Seed production Ex situ Wild species 



The author would like to thank Annette Miller, USDA ARS National Laboratory for Genetic Resources Preservation, Plant Germplasm Resources Preservation Program, Fort Collins, CO, for compiling the information in Table 11.1 and Stephanie Greene, Vicki Bradley, Susan Stieve, and Gail Eckwright for their thoughtful reviews of the chapter.


  1. Allen PS, Meyer SE (1998) Ecological aspects of seed dormancy loss. Seed Sci Res 8:183–192. CrossRefGoogle Scholar
  2. Anderson J (1999) Bringing native grasses into commercial production the responsibilities of the seed producers. California Native Grass Association, pp 21–22.
  3. AOSA (2016) 2016 AOSA rules for testing seed, vol 1–4. Association of Official Seed Analysts, Washington, DCGoogle Scholar
  4. Avendaño López AN, de Jesús Sánchez González J, Ruíz Corral JA, De La Cruz LL, Santacruz-Ruvalcaba F, Sánchez Hernández CV, Holland JB (2011) Seed dormancy in Mexican teosinte. Crop Sci 51(5):2056–2066Google Scholar
  5. Bartow A (2015) Native seed production manual for the Pacific Northwest. USDA-NRCS Corvallis Plant Materials Center, Corvallis, OR Google Scholar
  6. Baskin CC, Baskin JM (2001) Seeds: ecology, biogeography, and evolution of dormancy and germination. Academic Press, San DiegoGoogle Scholar
  7. Baskin CC, Baskin JM (2003) When breaking seed dormancy is a problem try a move-along experiment. Native Plants J 4(1):17–21CrossRefGoogle Scholar
  8. Bower AD, Clair J, Erickson V (2014) Generalized provisional seed zones for native plants. Ecol Appl 24(5):913–919CrossRefGoogle Scholar
  9. Breese EL (1989) Regeneration and multiplication of germplasm resources in seed genebanks: the scientific background. IBPGR, Rome, Italy Google Scholar
  10. Brenner DM (2005) Methods for Melilotus germplasm regeneration. Plant Genet Resour Newsl 141:51–55Google Scholar
  11. Brenner DM, Widriechner MP (1998) Amaranthus seed regeneration in plastic tents in greenhouses. Plant Genet Resour Newsl 116:1–4Google Scholar
  12. Brown AHD, Brubaker CL, Grace JP (1997) Regeneration of germplasm samples: wild versus cultivated plant species. Crop Sci 37:7–13CrossRefGoogle Scholar
  13. Burton CM, Burton PJ (2003) A manual for growing and using seed from herbaceous plants native to the northern interior of British Columbia. Symbios Research and Restoration, Smithers, BCGoogle Scholar
  14. Cane JH (1997) Ground-nesting bees: the neglected pollinator resource for agriculture. In: VII International Symposium on Pollination.
  15. Chandler JM, Jan CC (1985) Comparison of germination techniques for wild Helianthus seeds. Crop Sci 25:356–358. CrossRefGoogle Scholar
  16. Clement SL, Griswold TL, Rust RW, Hellier BC, Stout DM (2006) Bee associates of flowering Astragalus and Onobrychis genebank accessions at a Snake River site in Eastern Washington. J Kansas Entomol Soc 79(3):254–260CrossRefGoogle Scholar
  17. Clement SL, Hellier BC, Elberson LR, Staska RT, Evans MA (2007) Flies (Diptera: Muscidae: Calliphoridae) are efficient pollinators of Allium ampeloprasum L.(Alliaceae) in field cages. J Econ Entomol 100(1):131–135CrossRefGoogle Scholar
  18. Crossa J, Hernandez CM, Bretting P, Eberhart SA, Taba S (1993) Statistical genetic considerations for maintaining germ plasm collections. Theor Appl Genet 86(6):673–678CrossRefGoogle Scholar
  19. Currah L, Ockendon DJ (1984) Pollination activity by blowflies and honeybees on onions in breeders’ cages. Ann Appl Biol 105(1):167–176CrossRefGoogle Scholar
  20. Davies R, Di Sacco A, Newton R (2015) Germination testing: environmental factors and dormancy-breaking treatments. Technical information sheet 13b, Board of Trustees of the Royal Botanic Gardens, Kew, West Sussex, UKGoogle Scholar
  21. Dulloo ME, Hanson J, Jorge MA, Thormann I (2008) Regeneration guidelines: general guiding principles. In: Dulloo ME, Thormann I, Jorge MA, Hanson J (eds) Crop specific regeneration guidelines. CGIAR System-wide Genetic Resource Program, Rome, ItalyGoogle Scholar
  22. Finch-Savage WE, Leubner-Metzger G (2006) Seed dormancy and the control of germination. New Phytol 171:501–523. CrossRefPubMedGoogle Scholar
  23. Genebank Standards (1994) Food and agriculture organization of the United Nations, Rome, International Plant Genetic Resources Institute, RomeGoogle Scholar
  24. Gerling HS, Willoughby MG, Schoepf A, Tannas KE, Tannas CA (1996) A guide to using native plants on disturbed lands, Alberta Agriculture. Food and Rural Development, Edmonton, ABGoogle Scholar
  25. Ghazoul J (2006) Floral diversity and the facilitation of pollination. J Ecol 94(2):295–304CrossRefGoogle Scholar
  26. Gladis T (1996) Bees versus flies?-Rearing methods and effectiveness of pollinators in crop germplasm regeneration. In: VII International Symposium on Pollination, vol 437, pp 235–238Google Scholar
  27. Godin R (2007) Native seed production for crop diversification. Sustainable Agriculture Research and Education.
  28. Great Basin Restoration Initiative (1999). Accessed 23 Sept 2016
  29. Greene SL, Bell AB (2007) Alternatives to honeybees for pollinating clover (Trifolium L.) germplasm accessions. In: Proceedings 9th international pollination symposium on plant-pollinator relationships – diversity in action. Agriculture Research Services Publication, Washington, DC, pp 64–65Google Scholar
  30. Harper CA, Bates GE, Hansbrough MP, Gudlin MJ, Gruchy JP, Keyser PD (2007) Native warm-season grasses: identification, establishment and management for wildlife and forage production in the mid-South. University of Tennessee Extension, Knoxville, TN ISBN 978-0-9795165-0-4Google Scholar
  31. Hay FR, Probert RJ (2013) Advances in seed conservation of wild plant species: a review of recent research. Conserv Physiol 1(1):cot030. CrossRefPubMedPubMedCentralGoogle Scholar
  32. Horton H, Asay KH, Glover TF, Young SA, Haws BA, Dewey SA, Evans JO (1990) Grass seed production guide for Utah. Utah State University, Cooperative Extension AG 437, Logan, UTGoogle Scholar
  33. Houseal GA (2007) Tallgrass Prairie Center’s native seed production manual. Tallgrass Prairie Center, University of Iowa, USDA-NRCS Elsberry PMC, Iowa Crop Improvement AssociationGoogle Scholar
  34. Howlett BG (2012) Hybrid carrot seed crop pollination by the fly Calliphora vicina (Diptera: Calliphoridae). J Appl Entomol 136(6):421–430CrossRefGoogle Scholar
  35. Ison JL, Wagenius S, Reitz D, Ashley MV (2014) Mating between Echinacea angustifolia (Asteraceae) individuals increases with their flowering synchrony and spatial proximity. Am J Bot 101(1):180–189CrossRefGoogle Scholar
  36. ISTA (2017) International rules for seed testing. International Seed Testing Association, Zurich, SwitzerlandGoogle Scholar
  37. Jarlan A, De Oliveira D, Gingras J (1997) Pollination by Eristalis tenax (Diptera: Syrphidae) and seed set of greenhouse sweet pepper. J Econ Entomol 90(6):1646–1649CrossRefGoogle Scholar
  38. Jauker F, Wolters V (2008) Hover flies are efficient pollinators of oilseed rape. Oecologia 156(4):819–823CrossRefGoogle Scholar
  39. Johnson RC, Bradley VL, Evans MA (2002) Effective population size during grass germplasm seed regeneration. Crop Sci 42(1):286–290CrossRefGoogle Scholar
  40. Johnson RC, Bradley VL, Evans MA (2004) Inflorescence sampling improves effective population size of grasses. Crop Sci 44(4):1450–1455CrossRefGoogle Scholar
  41. Johnson RC, Bradley VL, Knowles RP (1996) Genetic contamination by windborne pollen in germplasm-regeneration plots of smooth bromegrass. Plant Genet Resour Newsl 106:30–34Google Scholar
  42. Johnson RC, Cashman MJ, Vance-Borland K (2012) Genecology and seed zones for Indian ricegrass collected in the southwestern United States. Rangel Ecol Manag 65(5):523–532CrossRefGoogle Scholar
  43. Johnson RC, Erickson VJ, Mandel NL, St Clair JB, Vance-Borland KW (2010) Mapping genetic variation and seed zones for Bromus carinatus in the Blue Mountains of eastern Oregon, USA. Botany 88(8):725–736CrossRefGoogle Scholar
  44. Johnson RC, Hellier BC, Vance-Borland KW (2013) Genecology and seed zones for tapertip onion in the US Great Basin. Botany 91(10):686–694CrossRefGoogle Scholar
  45. Kew Royal Botanic Garden, Millennium Seed Bank Partnership, Seed Information Database. Accessed 15 Nov 2016
  46. Klein AM, Vaissiere BE, Cane JH, Steffan-Dewenter I, Cunningham SA, Kremen C, Tscharntke T (2007) Importance of pollinators in changing landscapes for world crops. Proc R Soc Lond B Biol Sci 274(1608):303–313CrossRefGoogle Scholar
  47. Lawrence MJ (2002) A comprehensive collection and regeneration strategy for ex situ conservation. Genet Resour Crop Evol 49(2):199–209CrossRefGoogle Scholar
  48. Le Clerc V, Briard M, Granger J, Delettre J (2003) Genebank biodiversity assessments regarding optimal sample size and seed harvesting techniques for the regeneration of carrot accessions. Biodivers Conserv 12(11):2227–2236CrossRefGoogle Scholar
  49. Luna V, Figueroa M, Baltazar M, Gomez L, Townsend R, Schoper JB (2001) Maize pollen longevity and distance isolation requirements for effective pollen control. Crop Sci 41(5):1551–1557Google Scholar
  50. Lu Y, Waller DM, David P (2005) Genetic variability is correlated with population size and reproduction in American wild-rice (Zizania palustris var. palustris, Poaceae) populations. Am J Bot 92(6):990–997CrossRefGoogle Scholar
  51. Meyer SE (1992) Habitat-correlated variation in firecracker penstemon (Penstemon eatonii Scrophulariaceae) seed germination response. Bull Torrey Bot Club 119(3):268–279CrossRefGoogle Scholar
  52. Mueller I, Schmid B, Weiner J (2000) The effect of nutrient availability on biomass allocation patterns in 27 species of herbaceous plants. Perspect Plant Ecol Evol Syst 3(2):115–127CrossRefGoogle Scholar
  53. National Oceanic and Atmospheric Administration, National Centers for Environmental Information. Accessed 15 Aug 2017
  54. Native Plant Network. Accessed 15 Nov 2016
  55. Negri V, Tiranti B (2010) Effectiveness of in situ and ex situ conservation of crop diversity. What a Phaseolus vulgaris L. landrace case study can tell us. Genetica 138(9–10):985–998CrossRefGoogle Scholar
  56. Pfaff S, Gonter MA, Maura C (2002) Florida native seed production guide. USDA-NRCS Plant Materials Center, Brooksville, FLGoogle Scholar
  57. Potts SG, Biesmeijer JC, Kremen C, Neumann P, Schweiger O, Kunin WE (2010) Global pollinator declines: trends, impacts and drivers. Trends Ecol Evol 25(6):345–353CrossRefGoogle Scholar
  58. Rancho Santa Ana Botanic Garden (2016) General seed collection guidelines for California native plant species. Accessed 11 Aug 2016
  59. Real LA (1981) Nectar availability and bee-foraging on Ipomoea (Convolvulaceae). Biotropica Suppl Reprod Bot 13(2):64–69Google Scholar
  60. Richards CM, Lockwood DR, Volk GM, Walters C (2010) Modeling demographics and genetic diversity in ex situ collections during seed storage and regeneration. Crop Sci 50(6):2440–2447CrossRefGoogle Scholar
  61. Rose R, Chachulski CE, Haase DL (1998) Propagation of Pacific Northwest native plants. Oregon State University Press, Corvallis, ORGoogle Scholar
  62. Sackville Hamilton NR, Chorlton KH (1997) Regeneration of accessions in seed collections: a decision guide. Handbook for Genebanks No 5. International Plant Genetic Resources Institute, Rome, ItalyGoogle Scholar
  63. Schittenhelm S, Gladis T, Rao VR (1997) Efficiency of various insects in germplasm regeneration of carrot, onion and turnip rape accessions. Plant Breed 116:369–375CrossRefGoogle Scholar
  64. Shock MP, Shock CC, Feibert EB, Shaw NL, Saunders LD, Sampangi RK (2012) Cultivation and irrigation of fernleaf biscuitroot (Lomatium dissectum) for seed production. Hortscience 47(10):1525–1528Google Scholar
  65. Shuler RE, Roulston TA, Farris GE (2005) Farming practices influence wild pollinator populations on squash and pumpkin. J Econ Entomol 98(3):790–795CrossRefGoogle Scholar
  66. Song ZP, Lu BR, Zhu YG, Chen JK (2003) Gene flow from cultivated rice to the wild species Oryza rufipogon under experimental field conditions. New Phytol 157(3):657–665CrossRefGoogle Scholar
  67. Spicer PB, Dionne LA (1961) Use of gibberellin to hasten germination of Solanum seed. Nature 189:327–328. CrossRefGoogle Scholar
  68. St Clair JB, Kilkenny FF, Johnson RC, Shaw NL, Weaver G (2013) Genetic variation in adaptive traits and seed transfer zones for Pseudoroegneria spicata (bluebunch wheatgrass) in the northwestern United States. Evol Appl 6(6):933–948CrossRefGoogle Scholar
  69. Stephens LC (2008) Self-incompatibility in Echinacea purpurea. Hortscience 43(5):1350–1354Google Scholar
  70. Stevens R, Jorgensen KR, Young SA, Monsen SB (1996) Forb and shrub seed production guide for Utah. Utah State University, Cooperative Extension AG 501, Logan, UT, pp 1–51Google Scholar
  71. Sullivan JR (1984) Pollination biology of Physalis viscosa var. cinerascens (Solanaceae). Am J Bot 71(6):815–820CrossRefGoogle Scholar
  72. Tucson Plant Materials Center (2004) Native seed production. Coronado Resources Conservation and Development Area, Inc, USDA-NRCSGoogle Scholar
  73. USDA, Natural Resources Conservation Service, Plants Database. Accessed 15 Nov 2016
  74. Van Deynze A, Fitzpatrick S, Hammon B, McCaslin M, Putnam DH, Teuber L, Undersander DJ (2008) Gene flow in alfalfa: biology, mitigation, and potential impact on production. Council for Agricultural and Science Technology, Ames, IAGoogle Scholar
  75. van Hintum TJL, Sackville Hamilton NR, Engels JMM, van Treuren R (2002) Accession management strategies: splitting and lumping. In: Engels JMM, Ramanatha Rao V, Brown AHD, Jackson MT (eds) Managing plant genetic diversity. IPGRI, Rome, Italy, pp 113–120Google Scholar
  76. Velthuis HH, Van Doorn A (2006) A century of advances in bumblebee domestication and the economic and environmental aspects of its commercialization for pollination. Apidologie 37(4):421–451 <hal-00892201>CrossRefGoogle Scholar
  77. Von Mark VC, Romano G, Dierig DA (2012) Effects of after-ripening and storage regimens on seed-germination behavior of seven species of Physaria. Ind Crop Prod 35(1):185–191CrossRefGoogle Scholar
  78. Westrich P (1996) Habitat requirements of central European bees and the problems of partial habitats. In: Matheson A, Buchmann SL, O’Toole C, Westrich P, Williams H (eds) The conservation of bees. Linnean Society of London and the International Bee Research Association symposium series, vol 18. Academic Press Limited, London, pp 1–16Google Scholar
  79. Widrlechner MP, Abel CA, Wilson RL (1996) Ornamental seed production in field cages with insect pollinators. Comb Proc Int Plant Propag Soc 46:512–516 University of Washington-International Plant Propagation SocietyGoogle Scholar
  80. Widrlechner MP, Kovach DA (2000) Dormancy-breaking protocols for Cuphea seed. Seed Sci Technol 28(1):11–28Google Scholar
  81. Wilson MF, Price PW (1980) Resource limitation of fruit and seed production in some Asclepias species. Can J Bot 58(20):2229–2233CrossRefGoogle Scholar
  82. WorldClim-Global Climate Data. Accessed 15 Aug 2017

Copyright information

© This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply 2018

Authors and Affiliations

  1. 1.US Department of Agriculture – Agricultural Research Service, Plant Germplasm Introduction and Testing Research UnitWashington State UniversityPullmanUSA

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