0023-6152

AA00697606

4523

Unrefereed

0023-6152

AA00697606

Dwarfism in pea (Pisum sativum L.) manifests itself more conspiciously in the light, and light-induced epicotyl growth inhibition in relation to water status studied. NMR spin-lattice relaxation times (T[1])s of epicotyls of no-elongation zone were markedly longer than those of elongation zone of the seedlings of both cultivars, tall type cv. Alaska and dwarf type, cv. Progress No.9. T[1] of GA[1]-dose resopnse in dwarf pea, whichgrows normally, decreased in elogation zone while T[1]s in no-elongation zone increased. The changes in T[1] of light- and dark-grown pea epicotyls were not simply attribute to a change in water content. Water of dwarf control and no-elongation of GA[1]-treated cv. Progress No.9 grown under light condition was more sustained during three-hours air drying compared to those of cv. Alaska. Osmotic concentrationis in elngation zones were higher than those of no-elongation zone. In addion, there was no relationship between osmotic concentration and cell length. It seems that the epicatyl tissues of dwarf pea phenotype were high T[1] values accompanied by low osmotic values while water uptake was not changed. In conclusion, T[1] of the pea seedlings will be useful for an evaluation of the dwarfism and GA[1] dose-response to drought stress.