Longevity of seeds

Haageana asteraceae lesquerella palmeri brassicaeae e

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: torage time (in years) in which the greatest proportion of seeds germinated. Results and discussion The average initial germination percentage for species within the NPGS collection ranged from 76 to 99% [excluding A. graveolens (Apiaceae), Rheum spp. (Polygonaceae), Z. haageana (Asteraceae), Lesquerella palmeri (Brassicaeae), E. drobovii and E. hystix (Poaceae), which had low initial germination percentages] (Fig. 1A, Table 1). The average storage time was 38 years, and ranged from 81 [Lycopersicon esculentum (Solanaceae)] to 16 years [Senna obtusifolia (Fabaceae) and Eragrostis tef (Poaceae)] (Fig. 1B). The average final germination was 58%, and ranged from 100% [Hibiscus micranthus (Malvaceae), stored for 40 years] C. Walters et al. 4 Table 1. Storage performance of seeds in the USDA National Plant Germplasm System (NPGS) collection. The study includes accessions that were harvested between 1934 and 1975 and had initial germination percentages greater than 75% (except where indicated). Seeds were initially stored at 58C, but were transferred to 2 188C in 1978. Data for most species reflect storage for 24– 26 years at 2 188C. Initial and final germination values are averages calculated within 1 year of harvest and after the indicated storage time, respectively. Time courses were drawn for each species as shown in Fig. 2. Coefficients calculated from the Avramicurve fitting routine (see Methods section) were used to calculate the time for germination to decrease from the initial value to 50%, or to half of the initial germination for species with initial germination , 70%. Symbols by family names are used in Figs 5– 8. Letters in the family column adjacent to Gossypium species indicate the genome type Family Genus Species Apiaceae* Anethum Apium Carum Daucus Pastinaca Petroselinum Pimpinella Carthamus Cichorium Cichorium Cosmos Guizotia Helianthus Lactuca Lactuca Lactuca Lactuca Scorzonera Tagetes Tagetes Tagetes Tragopogon Zinnia Zinnia Zinnia Brassica graveolens graveolens carvi carota sativa crispum anisum tinctorius endive intybus sp. abyssinica annuus altaica sativa serriola virosa hispanica erecta patula sp. porrifolius haageana sp. violacea hirta (Sinapis alba) juncea napus oleracea abyssinica matronalis tinctoria sativum fendleri gordonii grandiflora palmeri officinale sativus vulgaris quinoa oleracea lanatus melo sativus argyrosperma (mixta) maxima moschata Asteraceae W Brassicaceae O Brassica Brassica Brassica Crambe Hesperis Isatis Lepidium Lesquerella Lesquerella Lesquerella Lesquerella Nasturtium Raphanus Chenopodiaceae V Beta Chenopodium Spinacia Cucurbitaceae B Citrullus Cucumis Cucumis Cucurbita Cucurbita Cucurbita Germination (%) No. of Final accessions Initial Avrami parameters Years stored Slope Intercept f P50 (years) 15 111 1 100 11 22 1 1049 17 4 1 1 36 1 499 5 1 1 5 11 38 5 2 7 12 4 39 87 76 85 85 85 95 87 91 87 81 76 92 99 97 99 99 88 91 93 90 95 74 89 86 94 15 33 40 9 22 11 24 69 63 56 72 38 42 9 2 8 78 67 83...
View Full Document

Ask a homework question - tutors are online