Seed germination protocols for Ex situ conservation of some Hypericum species from Turkey

Abstract

The availability of wild plants from different Hypericum species in Turkish flora is strongly limited due to uncontrolled harvesting. Thus, seed germination requirements of the four rare Hypericum species, namely H. orientale, H. perfoliatum, H. pruinatum and H. origanifolium were studied by performing some pre-soaking treatments with the aim of describing suitable germination protocols for use in ex situ conservation. Before placing the seeds in Petri dishes, they were soaked in 50, 100 or 150 mg L-1 GA; 0.5, 1 or 1.5% H2SO4; 150 mg L-1 GA + 0.5% H 2SO4, 0.01 solutions, tap water, 40, 50 or 60°C hot water for 30 min. The study was performed under a photoperiod of 18 h light/8 h darkness in growth chambers. In H. orientale and H. origanifolium, the highest germination was induced by H2SO4 1.5% in both species (81 and 52%, respectively) while GA 100 and 150 mg L-1 treatments produced the highest germination in H. perfoliatum (43%) and H. pruinatum (80%) seeds. The results indicated that propagation from seed is a viable method for the ex situ conservation of these species and germination response of the seeds to the pre-soaking treatments is variable. The changeable germination responses were discussed as a possible result of the dormancy involving partially dormant embryo for H. perfoliatum and H. pruinatum and hard seed coat for H. orientale and H. origanifolium. © 2007 Academic Journals Inc.