Growth Inhibitors in Xylem Exudates of Persian Walnuts (Juglans regia L.) and their Possible Role in Graft Failure
Year: 1983
Type: article
Abstract: When walnut trees were bark-grafted leaving nurse-limbs, xylem exudation was observed at a few slashes made low on the tree but not at graft junctures. Scions grew equally well on trees with slashes (74%) as those without slashes (86%). When the same treatments were made without nurse-limbs, 83% of the scions grew where exudates did not appear but only 21% grew where xylem sap exuded nearby. No dormant patch-bud placed in August-September grew the following spring if the sap flowed from any side of the patch, whereas 96% grew where no exudation occurred. Analysis of the xylem exudate revealed the presence of substances which inhibited growth of walnut calli and cucumber seedlings. A strong zone of inhibition on paper chromatograms coincided with the Rf of juglone, a powerful toxin which was identified by absorption spectrophotometry.
Authors: A.G. Prataviera, A.H. Kuniyuki, K. Ryugo
Institution: University of California, Davis
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,500
OpenAlex ID: W2476875129