Comparative Leaf Epidermal Anatomy of Mutants of Barley (Hordeum vulgareL. 'Himalaya') which Differ in Leaf Length

Abstract

Abstract We wished to determine the nature of differences in epidermal cell numbers and dimensions between leaves of different length in mutants of barley ( Hordeum vulgare L. ‘Himalaya’). Three comparisons were made: leaf one (L1) vs. leaf four (L4); wild type vs. nine dwarf mutants and wild type vs. a slender mutant. L1 was shorter than L4, and for most lines this was associated with a change in epidermal cell number for the blade, and in both cell number and length for the sheath. Compared to wild type, the smaller leaves of dwarf plants generally had shorter and fewer cells in both blade and sheath. The blade of slender plants was the same length (L1) or longer (L4) than wild type, while the sheath was longer than that of wild type for both L1 and L4. Slender plants had longer but fewer cells than the wild type along the blade of L1, and shorter but more cells for the blade of L4. In the sheath, slender plants had longer and more (L1) or fewer (L4) cells than did the wild type. For L1, variation in blade width amongst the barley lines was associated with a change in file width and file number. For L4, blade width varied only with file number, except for slender plants where narrow blades were associated with reduced file width. Hence there was no consistent correlation between changes in cell size or cell (or file) number with changes in leaf length or width. Differences depended on the leaf (L1 vs. L4), leaf part (blade vs. sheath), and the nature of the mutation (dwarf vs. slender).