Influence of 2,4-D and Sucrose on Somatic Embryogenesis in Sunflower (Helianthus Annuus L.) from Immature Zygotic Embryo

Abstract

The aim of the present study was to investigate the effect of different concentration of 2, 4-D on successive stages of direct somatic embryogenesis in three different cultivars, LSF-10, DMLT-1Y and GMU-479. In addition to this we studied a combined effect of 2, 4-D and sucrose. The results showed that a low concentration of 2, 4-D (1 mg/lit) stimulates the induction of  the globular stage somatic embryo and the number of correct embryos in direct somatic embryogenesis, while a high 2, 4-D concentration (3.3mg/lit) results in growth inhibition and turgor pressure loss of somatic embryos. Maximum somatic embryo induction was evident from GMU-479 (95.0%) cultivar in MS+0.4mg 2, 4-D (80.0%) was found the highest score. Moreover a high concentration of 2, 4-D changes calli color and decreases its proliferation rate.  2, 4-D was not showed any effect on the development of somatic embryos after proliferation to maturation. Nevertheless, we found a positive effect of increasing sucrose concentration for induction of somatic embryos from 6 to 12 % and no embryogenesis was observed at 3% sucrose.