Phosphorus uptake capacity of 14-year-old loblolly pine as indicated by a sup 32 P root bioassay

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Forest Science; (USA)

OSTI ID:6071913

Pennell, K D; Allen, H L; Jackson, W A ^[1]

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1. Univ. of Florida, Gainesville (USA) North Carolina State Univ., Raleigh (USA)

Excised loblolly pine roots were exposed to a {sup 32}P-labelled solution for 20 minutes to measure their capacity for P uptake. On five dates from March 1985 to March 1986, root samples were collected from 14-year-old loblolly pine which had received 101 kg P {center dot} ha{sup {minus}1} and 0 kg P {center dot} ha{sup {minus}1} when they were planted, Phosphorus uptake by roots of nonfertilized loblolly pine (1.10 {mu}mol P {center dot} g {sup {minus}1} {center dot} hr{sup {minus}1}) was significantly greater than that by roots of fertilized loblolly pine (0.72 {mu}mol P {center dot} g{sup {minus}1} {center dot} hr{sup {minus}1}) when sampled between June and October, but no difference was detected when sampled in March. Phosphorus uptake was decreased by approximately 50% at 7{degree}C compared to 25{degree}C, and in the presence of metabolic inhibitors. Phosphorus concentrations, measured after the bioassay, of roots from fertilized trees (0.93 g P {center dot} kg{sup {minus}1}) were significantly greater than those of roots from nonfertilized trees (0.45 g P {center dot} kg{sup {minus}1}) on all five sampling dates. Capacity for root P uptake did not have an advantage over root or foliar P concentrations as an indicator of P stress, and does not appear to be a practical diagnostic tool for semimature loblolly pine.

• OSTI ID: 6071913
• Journal Information: Forest Science; (USA), Journal Name: Forest Science; (USA) Vol. 36:2; ISSN FOSCA; ISSN 0015-749X
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CONIFERS
DAYS LIVING RADIOISOTOPES
ELEMENTS
FERTILIZERS
GROWTH
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
NONMETALS
NUCLEI
ODD-ODD NUCLEI
PHOSPHORUS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PINES
PINOPHYTA
PLANT GROWTH
PLANTS
RADIOISOTOPES
ROOT ABSORPTION
TRACER TECHNIQUES
TREES
UPTAKE