Somaclonal variation from Sorghum bicolor (L.) Moench cell culture

Abstract

Sorghum bicolor (L.) Moench, plants were regenerated from 4 to 5 month old callus cultures originally derived from seedling explants. Somaclonal variation was examined in the SC₂ and SC₃ generations of eight different clones plus the non-tissue cultured parent line. Characters examined included the area of the third leaf, height, tiller number, total shoot weight, seed number, grain yield, days to flowering, and chlorophyll content in the SC₂ generation. Some plants were phenotypically different from the parent line in the SC₂ generation. All clones were similar to the parent in third leaf area and chlorophyll content. Three clones had significant height reduction and six had significantly higher total plant matter production. Seven of the clones had significant increases in number of secondary tillers, and all had significant decreases in days to flowering. Only three clones had significant increases in grain yield and seed number; however, all the clones had smaller seeds. In subsequent studies of SC₂ and SC₃ generations of three somaclones, characters examined included height, tiller number, total shoot weight, and days to flower. In one of the somaclones none of the original differences in characters was maintained in two subsequent growing seasons in the SC₂ or SC₃ generation. The other two somaclones maintained the increased tiller number in the next growing season in both the SC₂ and SC₃ generations. In one of the somaclones plant height reduction occurred in the SC₂ and SC₃ generations. All other traits were not maintained.