[Induction of embryogenic calli from caryopses of common bermudagrass and ultrastructure of embryogenic cells as well as plant regeneration].

A tissue culture system for embryogenic callus (EC) induction and plant regeneration of common bermudagrass using mature caryopsis (embryos) as explants was developed. The results showed that embryogenic calli could be induced from caryopsis with high frequency, in MS medium with 2,4-D 2.0-6.0 mg/L, and the best concentration of 2,4-D was 4.0 mg/L. The best method for maintaining EC and tissue differentiation was to subculture EC in MS+2,4-D 4.0 mg/L 1-2 times, follwed by subculturing in 1/2 MS+2,4-D 2.0 mg/L for 1-2 times, then to transfer EC to 1/2 MS without hormone for a 10-d-preregeneration in light, followed by transferring to MS+6-BA 3.0 mg/L for regeneration, with regeneration frequency 31.7%. Morphological and micro-structural differences between EC and non-embryogenic callus (NEC) were observed by electron microscope. Ultrastructrual characteristics of the EC cells are described in this paper.