Does radial growth of the lichen Parmelia conspersa depend exclusively on growth processes at the lobe tip?

Richard A. Armstrong*, S.N. Smith

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

The objective of this study was to test the hypothesis that the radial growth of lobes of the lichen Parmelia conspersa depends largely on growth processes which occur at the lobe tip. First, individual lobes were removed from thalli and portions of the lobe removed to within various distances from the tip. Radial growth of the lobe was unaffected until less than 2 mm of the lobe tip remained. Second, the surfaces of individual lobes were painted with acrylic paint leaving different portions of the lobe exposed. Painting lobes to within 0.5 mm and 1 mm of the tip substantially reduced radial growth. Third, the levels of ribitol, arabitol and mannitol were measured in different regions behind the lobe tip on four occasions during 1994. The concentration of the three carbohydrates was greatest at the lobe tip and the levels declined linearly with distance from the tip. Fourth, painting one vertical half of the lobe tip did not affect radial growth but artificially bisecting the lobe tip with a scalpel reduced radial growth. Although transport of carbohydrate from other regions of the lobe cannot be ruled out, the results support the hypothesis that radial growth in P. conspersa depends largely on processes within a region approximately 2 mm behind the lobe tip.

Original languageEnglish
Pages (from-to)263-269
Number of pages7
JournalEnvironmental and Experimental Botany
Volume39
Issue number3
DOIs
Publication statusPublished - Jun 1998

Keywords

  • carbohydrate
  • lichen
  • lobe growth
  • parmelia conspersa
  • translocation

Fingerprint Dive into the research topics of 'Does radial growth of the lichen Parmelia conspersa depend exclusively on growth processes at the lobe tip?'. Together they form a unique fingerprint.

Cite this