Effect of warm and cold stratification, and ethanol treatment on germination of Corylopsis seeds

Abstract

Seed germination experiments with Corylopsis coreana, C. sinensis var. calvescens, and Corylopsis gotoana were conducted. Corylopsis coreana seeds were treated at 5, 7.5, 10, 12.5 and 20°C to study the upper temperature limit to break dormancy. Seeds of C. sinensis var. calvescens were treated 1 month with warm stratification (WS) at 10, 15, 20, and 25°C followed by cold stratification (CS) at 5°C for 0, 1, 2, and 3 months to understand the requirements of WS and CS to effectively break dormancy. Germination of Corylopsis seeds at 15-20°C without CS suggests that dormancy is considered shallow and the upper temperature limit to break is 12.5°C. Immersing seeds in water or ethanol induced seed germination which may result from leaching of inhibitors from the seed. Observation of seed coats following treatment with water and ethanol by means of low temperature scanning electron microscopy (LT-SEM) revealed elongated and rectangular/hexagonal shaped cells in C. coreana and irregular jigsaw puzzle-piece shapes in C. gotoana. In conclusion, dormancy in Corylopsis is considered shallow and the optimum CS is suggested to be 7.5°C, while the optimum WS is ranging from 12.5 to 20°C.

Germination of Hemerocallis Seeds as Influenced by Seed Development and Temperature Treatments

“…Mature Corylopsis coreana seeds with fully developed endosperm and cotyledons sink when immersed in water, as verified by X-ray images (Kim et al, 2016), with germination percentages higher than 85 -90%. However, the presence of air space in mature dry seeds between the seed coat and endosperm or embryo may prevent seeds from sinking when immersed in water.…”

The influence of ethanol as a solvent on the gibberellic acid-induced germination of Brachyscome and Allittia (Asteraceae) seeds

“…Other evidence has suggested that ethanol may break dormancy by acting as a substrate for respiration thereby stimulating glycolysis (Adkins et al 1984b;Corbineau et al 1991). One recent study postulated that soaking seeds in an ethanol solution may alter the morphology of the seed coat, thus causing inhibitory chemicals such as abscisic acid to be leached from seeds, resulting in increased germination (Kim et al 2016).…”

“…Miyoshi and Sato (1997) showed that concentrations of 1-5% ethanol over 10 days produced maximum germination of Oryza sativa L. Lycopersicon esculentum L. primed for 24 h with 2-4% ethanol improved germination (Afzal et al 2013). Higher concentrations of 25% ethanol for 15 min, or 25-75% ethanol for 10-120 min were used to overcome dormancy of Helianthus (Nasreen et al 2015) and Corylopsis (Kim et al 2016) species respectively.…”