P. Marschner et Dl. Godbold, MYCORRHIZAL INFECTION AND AGING AFFECT ELEMENT LOCALIZATION IN SHORT ROOTS OF NORWAY SPRUCE [PICEA-ABIES (L) KARST], Mycorrhiza, 5(6), 1995, pp. 417-422
Norway spruce [Picea abies (L.) Karst.] seedlings, nonmycorrhizal of m
ycorrhizal with Laccaria laccata or Paxillus involutus were grown in a
quartz sand-nutrient solution system for 6 months and then treated wi
th 5 mu M Pb for 4 days. Element contents of cortex cell wall of young
, medium and old short roots were determined by X-ray microanalysis of
longitudinal thin sections. The Pb content was influenced neither by
age nor by the distance from the root tip (up to 1.7 mm) but was signi
ficantly lower in the P. involutus mycorrhizae than in the L. laccata
mycorrhizae or in nonmycorrhizal short roots. In the P. involutus myco
rrhizae, the P content of the cortex cell walls was twice as high in y
oung mycorrhizae than in old mycorrhizae. In the nonmycorrhizal short
roots and the L. laccata mycorrhizae, P content was influenced neither
by age nor by distance from the root tip. The Ca and Fe contents of t
he cortex cell walls increased with age in the nonmycorrhizal short ro
ots and the mycorrhizae. It is concluded that the element content of t
he cortex cell walls of short roots is strongly influenced by age, whi
le the distance from the root tip seems to be of minor importance.