Effect of explants and concentrations of plant growth regulators on callus induction in Stipagrostis pennata

Stipagrostis pennata is one of the most important desert species to cover desert areas as well as to bind the sand which unfortunately cannot produce the best quality seed for its survival. This research was conducted to callus induction and experimental treatments included two types of explants (stem and seed), four various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) consists of 1, 2, 3 and 4 mg /L and five levels of 6-benzylaminopurine (BAP) consists of 0, 0.05, 0.1, 0.2 and 0.4 mg /L were applied to the Murashing and Skoog basal media. This study was conducted as a factorial experiment based on completely randomized design with three replications. Results showed a significant interaction effect among explants, auxin and cytokinin on the traits related to callus induction. Seed explant showed the maximum of callus induction percentage (100%) in medium containing 3 mg/l 2,4-D with both 0.4 or 0.2 mg/l of BAP. The highest percentage of callus induction in stem node explant (60%) was obtained in 3 mg/l 2,4-D with 0.4 mg/l BAP treatment. For the surface and fresh weight of callus in both explants and the volume of callus in seed explant, 3 mg/l 2,4-D with 0.4 mg/l BAP was recognized as the best treatments. Stem node explant in the of 2 mg/l 2,4-D with 0.1 mg/l BAP treatment showed the highest volume of callus. In general, the use of seed explant in mg/l 2,4-D and 0.4 mg/l BAP treatment can be introduced as an optimized protocol.