Effect of seed priming on germination and seedling growth of Chamomile under salinity

In‏ ‏order‏ ‏to‏ ‏study‏ ‏chamomile‏ ‏tolerance‏ ‏to‏ ‏salinity‏ ‏and‏ ‏find‏ ‏a way‏ ‏to‏ ‏increase‏ ‏its‏ ‏tolerance‏ ‏afactorial‏ ‏experiment‏ ‏was‏ ‏conducted‏ ‏in‏ ‏acompletely‏ ‏randomized‏ ‏design‏ ‏with‏ ‏three‏ ‏replications‏ ‏in‏ ‏‎2012.‎‏ ‏Seeds‏ ‏primed‏ ‏with‏ ‏salicylic‏ ‏acid‏ ‏and‏ ‏gibberellic‏ ‏acid‏ ‏‎(GA)‎‏ ‏at‏ ‏‎250‎‏ ‏ppm‏ ‏by‏ ‏a‏ ‏combination‏ ‏of‏ ‏the treatments‏ ‏at‏ ‏‎12‎‏ ‏and‏ ‏or‏ ‏‎24‎‏ ‏hours,‎‏ ‏‎12‎‏ ‏hours‏ ‏with‏ ‏salicylic‏ ‏acid‏ ‏after‏ ‏‎12‎‏ ‏hours‏ ‏in‏ ‏GA,‎‏ ‏and‏ ‏vice versa.‎‏ ‏The‏ ‏second‏ ‏factor‏ ‏included‏ ‏salinity‏ ‏levels‏ ‏‎(zero, 50, 100‎‏ ‏and‏ ‏‎150‎‏ ‏Mm NaCl). Germination percentage, mean germination time, germination rate, mean daily ‎germination time, daily germination rate, plumule or root length, and seed vigor and catalase ‎and peroxidase activity were measured. Results showed that salinity reduces germination ‎percentage, mean daily germination time, length of root and hypocotyl germination rate ‎whereas increased antioxidant enzyme activities. The greatest effect obtained by a ‎combination of salicylic acid-GA. The maximum activity of peroxidase belonged to salicylic ‎acid-GA and catalase activity by priming with salicylic acid at 24 hours.‎