tailieunhanh - Báo cáo lâm nghiệp: "Germination and storage of recalcitrant seeds of tropical forest tree specie"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Germination and storage of recalcitrant seeds of tropical forest tree species. | 89s Ann. Sci. For. 1989 46 supl. 89s-91s Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Germination and storage of recalcitrant seeds of some tropical forest tree species F. Corbineau and D. Come Laboratoire de Physiologie des Organes Végétaux après Récolte CNRS Meudon and Université Pierre-et-Marie-Curie Paris VI Paris France Introduction Seeds have been termed orthodox or recalcitrant by Roberts 1973 to describe their storage behavior. Orthodox seeds tolerate dehydration down to 5-10 dry weight basis without damage. Prepared in this manner these seeds can be stored for long periods and their viability can be prolonged at the lowest temperature and moisture content possible. Recalcitrant seeds are highly hydrated and they cannot withstand intensive desiccation. They originate predominantly from tropical or subtropical tree species. These seeds can only be stored in wet medium to avoid desiccation injury and at relatively warm temperature since most of them are sensitive to chilling King and Roberts 1979 . The aim of the present study was to analyze the germination of some recalcitrant seeds of tropical forest trees and the effects of dry and wet storage on their viability. Materials and Methods Experiments were carried out with seeds of two Dipterocarps collected in Thailand at the Phu Khac Botanical Garden Shorea roxburghii and the Meak Lek Arboretum Hopea odorata and seeds of Simarouba amara Simaroubaceae and Symphonia globulifera Guttiferae collected in the dense forest near Kourou French Guiana. Germination tests were performed in darkness at temperatures between 5 and 35 c on cotton wool saturated with deionized water and placed in plastic rectangular boxes 18 cm long X 12 cm wide X cm deep . 50-100 seeds were used in each test 10-25 seeds per box . To study the effect of dehydration on viability seeds were placed in open air at 20 C and 55 relative air humidity. Samples were periodically removed weighed and placed for germination at 30 C. .