Effects of pretreatments on seed dormancy and germination in endemic uluda flax ( linum olympicum boiss.) (linaceae)

Abstract

Linum olympicum Boiss. (Linaceae) is an endemic species to Turkey, and has both medicinal and ornamental properties. In this study, we investigated the effects of GA(3) and cold stratification (1 or 4months) on the germination and mean germination time in relation to breaking dormancy in this species under darkness (20 degrees C) and light (20/10 degrees C, 12/12h) conditions. Seeds were collected from specimens that spread on limestone or granite screes, ledges of rocky or turfy slopes, and hilltops of the alpine belt from Uluda Mt. (Bursa, Turkey, 2200-2300m). We show that a combination of hormone and cold stratification treatments promoted seed germination under darkness and light conditions. Non-stratified seeds germinated to 73% following 1000mgL(-1) GA(3) treatment and also it was 83% after 1month cold stratification. After 4months of cold stratification treatment, 10% and 53.3% of seeds successfully germinated after incubation in light and dark conditions, respectively. Hormone and cold stratification treatments also reduced mean germination time. Our results revealed that seeds of L. olympicum have physiological dormancy and require prolonged time for cold stratification and darkness for germination, rather than responding to the photoperiod. Germination requirements of L. olympicum have not been studied previously, and the data obtained could be used for the ex situ protection of this alpine species.