Effects of some pretreatments on germination of bladder-senna (Colutea armena Boiss. and Huet.) and smoke-tree (Cotinus coggygria Scop.) seeds.

This study was carried out to determine effects of pre-treatments including floating in hot water(100 degrees C) followed by continual cooling for 24 hr in the same water floating in tap water for 24 hr submersion in concentrate (98%) sulphuric acid (H2SO4) and cold stratification for different durations (20, 40 and 60 days) and their combinations on seed germination and to investigate how to overcome dormancy of seeds of Colutea armena Boiss. and Huet. and Cotinus coggygria Scop. The seeds were sown in polyethylene pots in the greenhouse and on seedbeds under open field conditions. The statistical design was a randomized complete block design with three replications. The highest germination percentage (77.19%), the best germination rate (16 days) and the highest growth rate (69.01%) were obtained from Colutea armena seeds that were submersed in sulphuric acid for 30 min and sown in the greenhouse. The pre-treatment of submersion in sulphuric acid for 20 min with cold stratification for 60 days gave the highest germination percentage (82.77%) and the highest growth rate (79.37%) in the greenhouse for Cotinus coggygria seeds. On the other hand, the best germination rate (9 days) was obtained from smoketree seeds that were cold stratified 60 days and sown under open field conditions. It can be stated that there is an affirmative effect of the greenhouse condition on germination percentage and growth rate values of the seeds used in this study

Effect of cold stratification treatments on germination of drought tolerant shrubs seeds.

This study was carried out to determine effects of different durations (20, 40, 60 days and control) of cold stratification treatments on seed germination and to overcome dormancy in seeds of twelve different drought tolerant plants. The species used in this study were Arbutus andrachne L., Cistus creticus L., Colutea armena Bois. Huet., Cotinus coggygria Scop., Cotoneaster numullaria Fisch. and Mey, Elaeagnus angustifolia L., Jasminum fruticans L., Paliurus spina-christii Mill., Punica granatum L., Pyracantha coccinea Roem., Rhus coriaria L., and Ziziphus jujuba Mill. The seeds were sown in polyethylene pots under greenhouse and on seedbeds under open field conditions. Statistical design was a randomized complete block design with three replications. Germinated seeds were counted and observed periodically for 90 days after sowing to determine germination percentages (GP) and germination rates (GR). While the highest GP were determined according to duration of cold stratification under greenhouse conditions for each species were 44.2% for 60 days, 2.5% for 20 days, 85.6% for 60 days, 13.5% for 20 and 60 days, 64.3% for 20 days, 11.2% for 60 days, 8.2% for 20 days and 14.1% for 20 days for Cotinus coggygria, Cotoneaster numullaria, Jasminum fruticans, Paliurus spina-christii, Pyracantha coccinea, Punica granatum, Rhus coriaria and Ziziphus jujuba respectively The highest GP were 16.5% forArbutus andrachne and 91.3% for Colutea armena for 20 days cold stratified seeds and sown under open field conditions. Furthermore, the highest GP were obtained from seeds of Cistus creticus (27.5%) and Elaeagnus angustifolia (56.2%) in control sowing.

Effects of cold stratification on germination rate and percentage of caper (Capparis ovata Desf.) seeds.

Caper is an important plant because of its high adaptability to marginal agriculture fields that are not suitable for agricultural crops. Different parts of caper such as roots, fruits, flowers and buds can be used to increase the inhabitant's income. The goal of this research is to determine germination rate and percentage of caper according to different duration of cold stratification (10, 20, 30, 40, 50 and 60 days) treatments. Cold stratification procedures under greenhouse condition were applied for eliminating seed dormancy to find the most suitable germination conditions because the presence of seed dormancy causes difficulties in seedling production. The seed germination started and stopped 21 and 57 days after sowing, respectively. While the highest germination percentage (46.6%) was obtained in seeds that were cold stratified for 60 days, the lowest germination percentage (3.6 7%) was determined in control seeds.