COMPARATIVE LEAF EPIDERMAL ANATOMY OF MUTANTS OF BARLEY (HORDEUM-VULGARE L HIMALAYA) WHICH DIFFER IN LEAF LENGTH

We wished to determine the nature of differences in epidermal cell num bers and dimensions between leaves of different length in mutants of b arley (Hordeum vulgare L. 'Himalaya'). Three comparisons were made: le af one (L1) vs. leaf four (L4); wild type us. nine dwarf mutants and w ild type us. a slender mutant. L1 was shorter than L4, and for most li nes 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 a nd fewer cells in both blade and sheath. The blade of slender plants w as the same length (L1) or longer (L4) than wild type, while the sheat h 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 (LI) or fewer (L4) cells than did the wild type. For L1, variation in blade width amongst the barley lines was a ssociated with a change in file width and file number. For L4, blade w idth varied only with file number, except for slender plants where nar row 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 t he leaf (L1 vs. L4), leaf part (blade us. sheath), and the nature of t he mutation (dwarf vs. slender). (C) 1997 Annals of Botany Company