Journal of Experimental Botany, Vol. 51, No. 344, pp. 635-643,
March 2000
© 2000 Oxford University Press
A study of water relations in neem (Azadirachta indica) seed that is characterized by complex storage behaviour
1 Centre National de Semences Forestières (CNSF), BP 2682, Ouagadougou, Burkina Faso
2 Department of Plant Sciences, Laboratory of Plant Physiology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands
Neem (Azadirachta indica) seed is reputed to have limited tolerance to desiccation, to be sensitive to chilling and imbibitional stress, and to display intermediate storage behaviour. To understand this behaviour the properties of water in seed tissues were studied. Water sorption isotherms showed that at similar relative humidity (RH), the water content was consistently higher in axes than in cotyledons, mainly due to the elevated lipid content (51%) in the cotyledons. Using differential scanning calorimetry, melting transitions of water were observed at water contents higher than 0.14 g H2O g-1 DW in the cotyledons and 0.23 g H2O g-1 DW in the axes. Beside melting transitions of lipid, as verified by infrared spectroscopy, changes in heat capacity were observed which shifted with water content, indicative of glass-to-liquid transitions. State diagrams are given on the basis of the water content of seed tissues, and also on the basis of the RH at 20 °C. Longevity was considerably improved, and the sensitivity to chilling/subzero temperatures was reduced when axis and cotyledons were dehydrated to moisture contents
of approximately 0.05 g H2O g-1 DW. However, longevity during storage at very low water contents was limited. A possible mechanism for the loss of sensitivity to chilling/subzero temperatures at low water contents is discussed. The results suggest that dry neem seeds in the glassy state have great potential for extended storability, also at subzero temperatures.
Key words: Azadirachta indica, chilling tolerance, desiccation tolerance, glassy state, seed storage.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
F. A. Hoekstra Differential Longevities in Desiccated Anhydrobiotic Plant Systems Integr. Comp. Biol., November 1, 2005; 45(5): 725 - 733. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. L. HOR, Y. J. KIM, A. UGAP, N. CHABRILLANGE, U. R. SINNIAH, F. ENGELMANN, and S. DUSSERT Optimal Hydration Status for Cryopreservation of Intermediate Oily Seeds: Citrus as a Case Study Ann. Bot., June 1, 2005; 95(7): 1153 - 1161. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Sacande, E. A. Golovina, A. C. van Aelst, and F. A. Hoekstra Viability loss of neem (Azadirachta indica) seeds associated with membrane phase behaviour J. Exp. Bot., May 1, 2001; 52(358): 919 - 931. [Abstract] [Full Text] [PDF] |
||||


