© 2000 Heron Publishing—Victoria, Canada
Seed germination of six mature neotropical rain forest species in response to dehydration
María Del Carmen Rodríguez (1), Alma Orozco-Segovia (1, 2), María Esther Sánchez-Coronado (1) and Carlos Vázquez-Yanes Sánchez-Coronado (1)
1. Instituto de Ecología, UNAM. Apartado Postal 70-275, Ciudad Universitaria, 04510 México, D. F. Mexico / 2. Author to whom correspondence should be addressed (cvazquez@miranda.ecologia.unam.mx) / Received December 16, 1998
Summary
We studied effects of dehydration and rehydration on germination of seeds of six mature tropical rain forest species—Cupania glabra Swartz, Cymbopetalum baillonii Fries, Poulsenia armata (Miq.) Standl., Stemmadenia donnell-smithii (Rose) Woodson, Rheedia edulis Triana & Planch. and an understory palm Chamaedorea alternans H. Wendl.—from Veracruz, México. Before the seeds were sown, their water content was reduced by 0 (control), 30, 54 and 72%
of their original water content. Dehydration affects the ability of seeds to rehydrate, as well as the rate and final percentage
of germination when seeds are subsequently rehydrated. Seed survival and germination behavior showed three patterns: (1) C. baillonii, P. armata and S. donnell-smithii had greater tolerance to seed dehydration than C. glabra, C. alternans and R. edulis; (2) partial dehydration enhanced germinability of C. glabra and C. baillonii seeds; and (3) partial dehydration of C. alternans and R. edulis seeds resulted in delayed or sporadic germination. A relationship was found between the effects of dehydration on germination
and the seasonality of seed production.
Keywords:
tropical seed germination, seed tolerance to dehydration, recalcitrant seeds, germination patterns.
