|Statement||A.S. Ouedraogo, K. Poulsen & F. Stubsgaard, editors.|
|Contributions||Ouedraogo, A. S., Poulsen, K., Stubsgaard, F., International Plant Genetic Resources Institute., DANIDA Forest Seed Centre.|
Intermediate recalcitrant tropical forest tree seeds The workshop was organized jointly with DANIDA Forest Seeds Centre, Humlebaek, Denmark. The workshop was held in recognition of the problems of handling and especially storing the seeds of many tropical tree species. Recalcitrant seeds must be stored at a moisture level similar to the level present when they were dropped from their tree, and oxygen must be available. Seeds with intermediate seed storage behavior can withstand some drying, though the amount of drying tolerated before viability is lost is dependent upon moisture content requirements of species. Since , the Danida Forest Seed Centre (DFSC) and IPGRI have cooperated in enhancing ex situ conservation methods for recalcitrant tropical forest trees. Project activities have focused on determining whether seeds are recalcitrant, intermediate or orthodox, and have included seed development research to assess optimal conditions for seed. Since the proportion of recalcitrant seeds is habitat dependent, recalcitrance becomes more relevant in particular habitats, such as tropical evergreen rain forests. Here it has been suggested that ca. 19% of the indigenous flora may produce recalcitrant seeds, a proportion that increases to c. 47% when looking at trees and shrubs.
Flores EM. Recalcitrant tree seed species of socioeconomic importance in Costa Rica: state of knowledge of physiology. In: Quédraogo AS, Poulsen K, Stubsgaard F, editors. Intermediate/ recalcitrant tropical forest tree seeds. Rome Humleback, Denmark: IPGRI DANIDA Forest Seed Centre; pp. – Challenges and opportunities for the enhanced use of recalcitrant and intermediate tropical forest tree seeds through improved handling and storage. In: IUFRO Seed Symposium "Recalcitrant Seeds": Proceedings of the conference (Ed. by M. Marzalina, K.C. Khoo, N. Jayanthi, F.Y. Tsan, and B. Krishnapillay), pp. The types are: 1. Orthodox Seeds and 2. Recalcitrant Seeds (Unorthodox Seeds). Seeds Type # 1. Orthodox Seeds: Orthodox seeds are long-lived seeds and can be successfully dried to moisture contents as low as 5% without injury and are able to tolerate freezing. Orthodox seeds are therefore, also termed as desiccation tolerant seeds. Intermediate and Recalcitrant Tropical Forest Tree Seeds. IPGRI-DFSC. Proceedings of a workshop on ‘Improved methods for handling and storage of intermediate and recalcitrant tropical forest tree seeds.’ June , Humlebaek, Denmark. IPGRI, Rome, Italy and Danida Forest Seed Centre, Humlebaek, Denmark.
IPGRI/DFSC Project on Handling and Storage of Recalcitrant and Intermediate Forest Tree Seed DFSC and the International Plant Genetic Resources Institute (IPGRI) (now Bioversity International) initiated a project, in , funded by Danida, on handling and storage of such seeds, involving many national institutes in the tropics. The project on handling and storage of recalcitrant and intermediate tropical forest tree seeds. DANIDA Forest Seed Centre Newsletter No. 4(April): Seed Moisture: Recalcitrant vs. Orthodox Seeds. Seeds of neem (Azadirachta indica A. Juss.), a multipurpose tropical tree, have limited desiccation r their intermediate storage behaviour might be caused by an elevated percentage of 4C nuclei in the embryo at maturity was investigated. Recalcitrant morphological traits and intermediate storage behaviour in seeds of Mesua ferrea, a tropical evergreen species Article (PDF Available) in Seed .