Seed Processing

( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

Documentation Documenting viability data is crucial for the efficient management of germplasm collections as it enables genebank staff to make informed decisions regarding the timely regeneration of material (see Chapter 8). Suggested descriptors to document accessionlevel information on viability (germination) testing include the following: • Number of seeds tested per replicate • Number of replicates • Method of germination testing • Date of germination testing • Duration of testing (or days of first and final counts) • Number of germinated seeds at first count Table 5.3. Concentration, temperatures and period of staining with tetrazolium solution (for Annex I crops of the International Treaty on PGRFA). Crop Species Preconditioning Staining Barley Hordeum vulgare Imbibe or soak, 6–18h 0.5%, 3h, 30°C Beans Phaseolus spp. Imbibe 18–24h, then soak, 2–3h 0.5–1%, 6–24h, 30°C Brassica Brassica spp. Imbibe or soak, 16–18h 0.5–1%, 3–6h, 30°C Chickpea Cicer arietinum Imbibe or soak, 18h 1%, 6–24h, 30°C Cowpea Vigna unguiculata Soak, 22h 0.5–1%, ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

16–24h, 30°C Eggplant Solanum melongena Imbibe or soak, 18h 0.5–1%, 6–24h, 30°C Faba bean Vicia faba Soak, 22h 0.5–1%, 16–24h, 30°C Finger millet Eleusine corocana Soak, 18h, 5°C 0.5%, 3h, 30°C Lentil Lens culinaris Imbibe, 18h, then soak, 2–3h 1%, 6–24h, 30°C Maize Zea mays Imbibe or soak, 18h 0.5–1%, 2–6h, 30°C Pea Pisum sativum Imbibe 18–24h, then soak, 2–3h 0.5–1%, 6–24h, 30°C Pearl millet Pennisetum glaucum Imbibe or soak, 6–18h 0.5–1%, 6–24h, 30°C Rice Oryza sativa ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

Imbibe or soak, 18h 0.5%, 3h, 30°C Rye Secale cereale Imbibe or soak, 6–18h 0.5%, 2–3h, 30°C Sorghum Sorghum bicolor Imbibe, 16h, 30°C 0.5–1%, 0.5–1h, 40°C Sugar beet Beta vulgaris Imbibe or soak, 16–18h 1%, 24–48h, 30°C Sunflower Helianthus annuus Imbibe or soak, 18h 0.5–1%, 3–6, 30°C Triticale Triticosecale Imbibe or soak, 6–18h 0.5%, 2–4h, 30°C Wheat Triticum aestivum Imbibe or soak, 6–18h 0.5%, 2–4h, 30°C 76 Handbooks for Genebanks No. 8 • Dormant/hard seeds at first count (%) • Special treatments for dormancy breaking (if any) • Final germination (% normal seedlings) • Abnormal germination (%) • Dead seeds (%) • Tolerance levels for statistical accuracy Further reading Association of Official Seed Analysts. 2005. Rules for testing seeds. Association of ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

Official Seed Analysts, USA. Baskin, C. C. and Baskin, J. M. (1998) Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination. Academic Press, San Diego, USA. Ellis, R.H., Hong, T.D and Roberts, E.H. 1985. Handbook of seed technology for genebanks. Volume 1: Principles and methodology. Handbooks for Genebanks. No. 2. IBPGR, Rome, Italy. FAO/IPGRI, 1994. Genebank standards. FAO and IPGRI, Rome, Italy. ISTA. 2003. ISTA Handbook for Seedling Evaluation. International Seed Testing Association. Bassersdorf, Switzerland. Figure 5.9. Staining pattern after tetrazolium test in dicot seeds. Illustrations depict both sides of seeds. Numbers 1–6 are germinable seeds and numbers 7–15 are nongerminable seeds (adapted from AOSA, 2005). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 77 Manual of Seed Handling ISTA. 2005. International Rules for Seed Testing. Edition 2005. International Seed Testing Association, Bassersdorf, Switzerland. Smith, R.D., Dickie, J.B., Linington, S.H., Pritchard, H.W and Probert, J.R. (eds.). 2003. Seed conservation: Turning science into practice. Royal Botanic Gardens, Kew, UK. 5.2 Seed health testing What is seed health? Seed health refers to the disease status of a seed sample and the presence or absence of disease-causing organisms and pests. What is seed health testing? Seed health tests determine the status of a seed sample, seed lot or accession with regard to diseases affecting that crop or wild species. Figure 5.10. ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )