Investigating the type of seed explant and carbon source on optimization of in vitro production of Festuca araundinacea callus

Tall fescue is an open pollinated cool season turf grass. Micropropagation and genetic transformation of monocot species have always experienced low genetic transformation efficiency. Therefore, evaluation of explant types and carbon source in media, likely through callus optimization would lead to the genetic transformation improvement which is the goal of this experiment. After surface sterilization of tall fescue seeds, different seed explants with or without embryo, have used to evaluate callus induction ability. Normal sugar, maltose and equal amount of sugar and maltose were also used as a different source of carbon in a completely randomized design with three replications. Finally, embryogenic calli, induced to produce shoots in MS media supplemented with 10 mg/L 2,4-D and 0.05 mg/L BA. The presence of embryo on explant is a necessity for callus induction. Explant without embryos which were cut differently failed to produce callus. The assessment of three carbon source during the course of multiplication under in vitro culture indicated that sucrose and maltose significantly improved total chlorophyll and carotenoid content in regenerated shoots while MS media with equal amount of both aforesaid carbon sources were not effective. The results gained in the present experiment indicated that embryo-contained cross section of seeds and using maltose was the best explant and the best carbon source for callus induction and shoot proliferation respectively.