Temperature Sensitivity of the Low-moisture-content Limit to Negative Seed Longevity–Moisture Content Relationships in Hermetic Storage

Autor: Richard Ellis, T. D. Hong
Rok vydání: 2006
Předmět:
Zdroj: Annals of Botany. 97:785-791
ISSN: 1095-8290
0305-7364
DOI: 10.1093/aob/mcl035
Popis: BACKGROUND AND AIMS The negative logarithmic relationship between orthodox seed longevity and moisture content in hermetic storage is subject to a low-moisture-content limit (m(c)), but is m(c) affected by temperature?Red clover (Trifolium pratense) and alfalfa (Medicago sativa) seeds were stored hermetically at 12 moisture contents (2-15 %) and five temperatures (-20, 30, 40, 50 and 65 degrees C) for up to 14.5 years, and loss in viability was estimated.Viability did not change during 14.5 years hermetic storage at -20 degrees C with moisture contents from 2.2 to 14.9 % for red clover, or 2.0 to 12.0 % for alfalfa. Negative logarithmic relationships between longevity and moisture contentsm(c) were detected at 30-65 degrees C, with discontinuities at low moisture contents; m(c) varied between 4.0 and 5.4 % (red clover) or 4.2 and 5.5 % (alfalfa), depending upon storage temperature. Within the ranges investigated, a reduction in moisture content below m(c) at any one temperature had no effect on longevity. Estimates of m(c) were greater the cooler the temperature, the relationship (P0.01) being curvilinear. Above m(c), the estimates of C(H) and C(Q) (i.e. the temperature term of the seed viability equation) did not differ (P0.10) between species, whereas those of K(E) and C(W) did (P0.001).The low-moisture-content limit to negative logarithmic relationships between seed longevity and moisture content in hermetic storage increased the cooler the storage temperature, by approx. 1.5 % over 35 degrees C (4.0-4.2 % at 65 degrees C to 5.4-5.5 % at 30-40 degrees C) in these species. Further reduction in moisture content was not damaging. The variation in m(c) implies greater sensitivity of longevity to temperature above, compared with below, m(c). This was confirmed (P0.005).
Databáze: OpenAIRE