Transport rates and concentration gradients during grain filling in wheat

Conference · Tue Apr 01 04:00:00 EST 1986 · Plant Physiol., Suppl.; (United States)

OSTI ID:5004733

Fisher, D B; Gifford, R M

Short-term mass transport rates into wheat ears were calculated at mid grain fill from /sup 32/PO/sub 4/ translocation velocities and sieve tube sap concentrations in the peduncle. Over a wide range of velocities (8.5 to 170 cm/hr), sieve tube sap concentrations (514 to 1050 milliosmolal) and grains per ear (20 to 54 in intact ears, as few as 7 in partially degrained ears), there were no evident differences in the rate of mass transport per grain through the peduncle. Increased sieve tube sap concentration was accompanied in the endosperm cavity sap by increased sucrose concentration, but amino acid concentration and total osmolality remained essentially constant. Thus the rate of transport into the grains appeared to remain constant in spite of altered concentration gradients across the crease tissues of the grain and changing sucrose concentration in the endosperm cavity. The constancy of endosperm cavity sap osmolality suggests that osmoregulatory processes in the grain may play a role in regulating transport rate into the grain.

• Research Organization: Washington State Univ., Pullman
• OSTI ID: 5004733
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 80:4
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL LOCALIZATION
CARBOHYDRATES
CEREALS
DAYS LIVING RADIOISOTOPES
DISACCHARIDES
GRASS
ISOTOPES
LABELLING
LIGHT NUCLEI
NUCLEI
ODD-ODD NUCLEI
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS 32
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
PLANTS
RADIOISOTOPES
RADIONUCLIDE KINETICS
RIPENING
SACCHARIDES
SACCHAROSE
SEEDS
WHEAT