Effect of Priming on Dormancy Breaking and Seedling Establishment of Caper (Capparis spinosa L.)

Abstract

Caper (Capparis spinosa) has deep roots, drought tolerant species, and produces a satisfactory vegetative cover which protects soils from erosion; it can be highly useful for the prevention of land degradation. Domestication of capers as medicinal, vegetable or soil surface coverage plant is complicated by limited and variable seed germination under artificial conditions. In order to examine the role of different levels of KNO3 (0, 500, 1000, 2000, 4000 and 8000 ppm) and gibberellic acid (GA3) (0, 50,100, 250, 500, 1000 and 2000 ppm) and durations (3, 12, 24 and 48 hr) on germination of Iranian caper seeds. In general 2000 mg/l gibberellic acid treatment resulted in more vigorous seed germination (42%) at any duration compared to any other concentration of the gibberellic acid. The highest seed germination of 26% was achieved when the seeds were treated 24 hour with 4000 ppm KNO3 solution but it was decreased in 8000 mg/l. The highest germination percentage (72%) was observed in seeds placed in filter papers wetted with in 250 ppm gibberellic acid after treatment with 8000 mg/l KNO3 for 24 hour (this duration was the best time span in two previous experiments). It seems that GA3 and KNO3 can replace partly to improve seed germination of caper. The highest seedling dry weight was achieved as seeds were treated in 100 ppm gibberellic acid plus 1000 ppm potassium nitrate. Therefore, it can be concluded that for best germination percentage of caper seeds, 250 ppm GA3 and 8000 ppm KNO3 and for the strongest seedling 100 ppm GA3 plus 1000 ppm KNO3 could be recommended.