THE EFFECT OF SALICYLIC ACID ON GERMINATION , GROWTH AND CHEMICAL CONTENTS OF BARLEY PLANT ( HORDEUM VULGARE L. )

Abstract

A laboratory study was conducted in Petri dishes to know the effect of different concentration ( 0 , 25 , 50 , 75 and 100 ) mg / l of salicylic acid on seed germination of barley plant .Another study in plastic pots to know the effect of salicylic acid at the same concentration on growth as measured on the length of the shoot and root system and the dry weights of them and the mean of leaves number and the leaves area . The results of the study were revealed that , the increase of salicylic acid causes an increase in seed germination percentage that was reached (%100) , at the treatments (75 and 100) mg / l , there was no significant difference between them , but a significant difference were noticed between them and other treatments . It was noticed an increase on lengths of shoot and root systems at all treatments , the high increase at the treatment (100) mg /l that reached ( 18 and 30) cm , and the percentage of dry matter ( 39.52 and 30.90 ) , respectively , also the increases of salicylic acid concentration causes an increase on the concentration of carbohydrates and proteins the high concentration of carbohydrates was ( 48.3) µg / gm at the treatment ( 100 ) mg / l , whereas the low concentration (27.3) µg / gm at the control treatment, the high concentration of protein (6.91) µg / gm on the same treatment , it was found a significant differences on the concentration of carbohydrates and proteins between the different treatments .The high concentration of total chlorophyll and carotene are at the treatment (100) mg / l that reached (1.30 and 0.30) mg / 100 gm fresh weight , respectively , whereas the low concentration in the control it was reached ( 0.62 and 0.20) mg / 100 gm fresh weight , respectively.