Anatomical characterization of reduced culm length mutants in barley (Hordeum vulgare L.)

Six true breeding reduced height mutants of barley were subjected to morphological and anatomical characterization for determining the causes for decrease in culm length. Data were collected on cell number (both in vertical and horizontal directions), cell length, cell width and cell volume from anatomical sections of upper and middle internodes of culm of all mutants and parental control. In all these mutants (except lax spike mutant) the shoot system was altered in one way or other with significant reduction in plant height mainly because of decrease in upper and middle internode length. Cell length in the mutants decreased significantly in both the upper and middle internodes of culm though the extent of reduction was much more in the cells of upper internode. Cell width, on the other hand, exhibited a marked increase in the mutants. Cell number recorded an increase in vertical direction in majority of mutants while there was marked decrease for the same trait in horizontal direction. The data suggests that decrease in cell length (due to failure of normal cell elongation) was the main cause of height reduction in dwarf mutants of barley studied here.