IN VITRO CULTURE OF WHEAT TISSUES. I. CALLUS FORMATION, ORGAN REDIFFERENTIATION AND SINGLE CELL CULTURE

Abstract

Callus induction, organ formation from callus and single callus cell culture have been tried in wheat. Though kinetin showed no effects, supplements of 2,4-D (1~10mg/1) or IAA (50mg/1) to the basal media induced calluses from seedling roots of einkorn, emmer and common wheats, and from stem pieces of common wheat. The best callus growth was obtained when casein hydrolysate (1g/1) or coconut milk (1%) was added to the basal media. Callus growth was also vigorous when 2,4-D (0.5~2.0mg/1) was added. Root formation from callus took place in all kinds of tested media, except those containing no growth factors or supplemented with 2,4-D at high concentrations (1~5mg/1). Shoot formation occurred in six cases and no growth factors were found to be specifically effective on shoot differentiation. Two plants were restored and reached maturity. Calluses of common wheat consisted of eudiploid and aneuploid cells at almost the same frequencies. The great majority of aneuploid cells had 42 ± 3 chromosomes. The restored plants showed normal chromosome constitution. Single callus-cell suspensions were obtained by the liquid culture of seeds in a shaker. A filtrate of the single cell suspension was plated on a solid agar medium, and some colonies were formed. However, plating efficiency was very low and colony growth was slow.