ALBERT

Description:    Poor seed germination is a significant problem for propagation of teak and it particularly hampers the deployment of genetically improved material into plantations. Seed dormancy is the putative cause for delayed and sporadic germination of teak seed but specific dormancy mechanisms have not been proven. In this paper we investigate whether physical or mechanical dormancy could affect teak germination. Physical dormancy was disproved when we observed water in every examined locule of fruit which had been immersed for 12–24 h ( n  = 1,700 fruits from six diverse sources). Mechanical dormancy was found to affect teak seed germination by means of valve structures which must open for the radicle to emerge. All 1,450 germinating seeds in 16 samples emerged from the endocarp via the detachment of a valve. Germination over 16 days was compared between extracted seeds (ex situ) and seeds within their endocarp (in situ) to determine the effect of mechanical dormancy on germination. Significantly greater germination of the ex situ seeds (62 ± 2% SE; n  = 486) than of the in situ seeds (32 ± 2% SE; n  = 564) indicated that mechanical dormancy is an important factor in the poor germination of teak. Content Type Journal Article Pages 1-11 DOI 10.1007/s11056-011-9298-0 Authors Nigel J. Slator, School of Environmental Science and Management, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia Andrew N. Callister, Department of Forest and Ecosystem Science, The University of Melbourne, Water Street, Creswick, 3363 Australia J. Doland Nichols, School of Environmental Science and Management, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia Journal New Forests Online ISSN 1573-5095 Print ISSN 0169-4286