2026-09-18T19:34:24Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/67450 2023-07-11 col_2142_5131 col_2142_14798 com_2142_5130 com_2142_686 com_2142_397

Cline, Molly Niedbalski 2014-12-14T04:37:48Z 2014-12-14T04:37:48Z 10000-01-01 1980 1980 Geraniums are largely propagated by cuttings even though new seed strains are now becoming popular. They are available as unrooted, callused redi-root (adventitious root initials just beginning to emerge) or fully rooted cuttings. Blackleg, caused by Pythium species, is a problem in geranium propagation. Cuttings of Pelargonium hortorum 'Yours Truly' were inoculated with an isolate of Pythium ultimum. Extensive basal stem rot occurred on all freshly broken cuttings. A restricted basal stem rot occurred on cuttings that had healed 1 day in soil prior to inoculation. Basal stem rot rarely occurred on cuttings that had healed 2 days or longer prior to inoculation. The wound-healing process in cuttings was studied using histological and histochemical techniques. After 1 day a distinct morphological change occurred in the cell walls of all tissues nearest the wounded surface. The cell walls became thickened due to deposition of substance in a layer around the cell wall. Histochemical tests determined this substance to be suberin. Suberin deposits were also observed in the intercellular spaces. A wound callus developed after 7-10 days. A suberized wound periderm developed after 14-21 days. Disease severity and the length of time after wound healing began were inversely correlated. Made available in DSpace on 2014-12-14T04:37:48Z (GMT). No. of bitstreams: 1 8108470.pdf: 5740724 bytes, checksum: dc9c39e09c13bfb02696dcffdc62258c (MD5) Previous issue date: 1980 Embargo set by: Seth Robbins for item 67628 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 127 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980. http://hdl.handle.net/2142/67450 (UMI)AAI8108470 eng Agriculture, Plant Pathology The Histology and Histochemistry of The Wound-Healing Process in Geranium Cuttings in Relationship to Basal Stem Rot Caused by Pythium Ultimum text Plant Pathology Plant Pathology University of Illinois at Urbana-Champaign Dissertation Ph.D.