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The role of the sheath tube in the development of expanding leaves in perennial ryegrass
Author(s) -
WILSON RUTH E.,
LAIDLAW A. S.
Publication year - 1985
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1985.tb03128.x
Subject(s) - biology , lamina , tube (container) , anatomy , perennial plant , lolium perenne , apex (geometry) , botany , materials science , composite material
SUMMARY A possible morphogenic effect of leaf sheaths on subsequent leaf development was investigated by varying sheath tube (pseudostem) length in plants of perennial ryegrass ( Lolium perenne ) cv. Talbot by either incising longitudinally or excising the distal portion of the sheath tube, while leaving the basal length of the tube intact. The tube was maintained at predetermined lengths by incising and excising new growth daily. The youngest rapidly expanding leaf was allowed to grow through the tube and was measured when fully expanded. Reducing tube length by excision or by incision from 60 mm to just above the cowl leaf on the apex reduced lamina length by 87% and 77% respectively. Over all tube lengths, laminae in incised treatments were almost twice as long as those in excised treatments. Sheath length followed a similar pattern. The effect on developing leaves of artificially extending sheath tubes (previously excised to 15 mm) to 30 or 45 mm with foil was similar to that of initially excising sheath tubes to 30 or 45 mm. The shorter the sheath tube (reduced by incision) through which the leaves had to grow, the shorter the cells, especially in the laminae. The estimated cell number per row along the length of the laminae ranged from 190 in tillers (shoots) with a very short tube (just above the cowl leaf) to 454 in intact control tillers. It is concluded that the sheath tube has a morphogenic influence on the development of subsequent leaves due to the change in environment of the leaf lamina on appearance, affecting both cell elongation and cell division.