EFFECT OF GA3 ON GERMINATION CHARACTERISTICS AND SEEDLING GROWTH UNDER SALT STRESS IN MAIZE

Abstract

A factorial experiment was carried out in the pots during fall 2012 and spring seasons 2013 with two factors in order to study the effect of seeds soaking with gibberellic acid to improve attributes of germination and seedling growth under effect of salt stress in maize (cv. 5018). First treatment was soaking seeds with gibberllic acid GA3 300 ppm for 24 h and non soaked. Planting media were distilled water only, 1000, 2000, 3000, 4000 ppm NaCl. The results showed superiority seeds soaked with gibberellic acid in giving least averages for faster start of germination, the ratio of sodium to potassium , the highest averages for the percentage of germination in the first and final count and chlorophyll content , but for the concentrations of NaCl the planting media of distilled water only(Control) gave lowest averages for faster start and ratio of Na+: K+, and the highest averages for the first and the final count, but noted increase average of faster start of germination and the ratio of sodium to potassium and low germination percentage in the first count and the final when increase the concentrations of NaCl increased. The results showed significant effect of intraction between soaking treatment or non with gibberellic acid and NaCl concentration in most of the studied attributes in most circumstances. We conclude that stimulate seed with gibberellic acid led to improved germination and its properties, also gibberellic acid had role in improving chemical indicators associated with plant tolerance to salinity such as increased chlorophyll content and low ratio of sodium to potassium seedling for seedling of stimulated seed with gibberellic acid compared with non stimulated seed. We recommend to soak maize seeds with gibberellic acid (300 ppm) for 24 h before planting, especially in the salt affected soil, also carry out further studies on influence of soaking seeds or seeds stimulated with gibberellic acid on growth and yield attributes of maize under the influence of saline stress.