|Da. Silva, Amaral|
Submitted to: Brazilian Journal of Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2006
Publication Date: 3/31/2006
Citation: Eira, M.T.S., E.A. da Silva, R.D. de Castro, S. Dussert, C. Walters, J.D. Bewley and H.W.M. Hilhorst. 2006. Coffee seed physiology. Brazilian Journal of Plant Physiology 18:149-163. Interpretive Summary: Considerable advances in our understanding of coffee seed physiology have been made in recent years. However, despite intense research efforts, there are many aspects that remain unclear. This paper gives an overview of the current understanding of the more important features concerning coffee seed physiology, and provides information on recent findings on seed development, germination, storage and longevity.
Technical Abstract: There are more than 70 species of Coffea (Rubiaceae), but only C. arabica and C. canephora are used commercially. Better understanding of seed physiology within Coffea will facilitate the incorporation of genetic traits for resistance to biotic and abiotic stresses from wild relatives into commercial varieties. During seed maturation, a 90 to 360 day period depending on species, complex carbohydrates are accumulated in the endosperm and triacylglycerols are deposited in the embryo. Embryos acquire the ability to germinate in vitro early in the embryogenic program and acquire partial tolerance of desiccation when fruits mature past the green stage and become yellowish green. Seeds of many Coffea species are considered to have ‘intermediate’ storage physiologies because they do not survive complete desiccation or subzero temperatures. Seeds of a few Coffea species (e.g. C. liberica) have classically recalcitrant storage physiologies. Ongoing research focuses on cryopreservation protocols for Coffea germplasm to ensure conservation of valuable genetic resources. Germination, which is slow under field conditions, is marked by fluctuations in turgor potential, increased endo-mannanase activity, and loosening of endosperm and cell wall structure. Numerous laboratories world-wide are cooperating in research to improve Coffea seed quality, longevity and germination efficiency.