Evaluation of stand establishment and growth performance of wheat in response to different water potential levels

Early growth of a germinated wheat seed was characterized with changes in vermiculite water potentials (ψw -0.03 to -1.10 mpa) and pots depth (10 to 30 cm). deionized water was added in vermiculite for a desired ψw treatment. germinated seeds of 5-mm radicles were planted in pots and glass boxes. experiments were conducted in controlled condition in a growth chamber. periodic samples were taken on each sampling day to measure roots and shoot of young wheat plant. leaf area was markedly sensitive to decrease in ψw from -0.03 to -0.60 mpa with no leaf visibility at ψw -1.10 mpa in 25 days old seedlings. dry matter (dm) decreased by reducing ψw,but this reduction in dm was associated to both shoot and roots losses. dm of seedhull increased by decrease in ψw. no changes in dm were observed in early 7 days growth at ψw -0.03 and -0.15 mpa. seminal roots number did not differ at higher ψ w but markedly decreased at low ψ w. the root length showed a linear reduction by decrease in ψw from -0.03 to -1.10 mpa. root branch length also shrank markedly at high (ψw -0.03 to -0.06) to moderate (ψw -0.60 to -1.10) decrease inψw. root length to weight ratio was linear but negatively related to decrease in ψw with a linear positive change with time after the seed transplanting. osmotic potential and tissue moisture content declined in a linear fashion by the decrease in ψw for different parts. dm of shoot and roots was observed in exponential fashion to dm of seed-hull and time to the transplanting. a linear but negative relationship was noted for shoot and roots to seed-hull fractional contribution in dm (fcdm). the study suggests marked sensitivity of root and shoot to reduction in ψw in the early development stages of wheat plant. reduction in ψw markedly decreased roots and branch number and their length,which inhibited leaf initiation. © 2015 university of agriculture. all rights reserved.