Effect of flooding, pH and high temperature on germination behavior of two common heliotrope (Heliotropium europaeum) populations

To study the response of seed germination and early growth of common heliotrope (Heliotropium europaeum) in different environmental conditions, three separate experiments were conducted. Treatments were the effect of different waterlogging levels 0, 1, 2, 4 and 8 days; acidity levels at seven levels 4, 5, 6, 7, 8, 9 and 100 and high temperature levels at nine levels 60, 80, 100, 120, 140, 160, 180, 200 and 220°C; the percentage and rate of germination, root and shoot length and fresh weight of seedlings was studied in two populations of Karaj and Ahvaz. The results showed that with increasing the duration of waterlogging in Karaj and Ahvaz all traits in both populations declined, so that the 8 days waterlogging H. europaeum growing in both populations completely stopped. With increasing pH from 4 to 7 percentage and germination rate gradually increased. The effect of high temperatures on germination levels in both populations showed an inverse relationship between increasing oven temperature and traits there. So that, by increasing the oven?s temperature the percentage rate of germination, root and shoot length and also seedlings fresh weight of two populations significantly declined.