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Submitted to: Journal of Horticultural Science and Biotechnology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/1/2004 Publication Date: 3/1/2005 Citation: Scagel, C.F. 2005. Isolate-specific rooting responses of leucothoe fontanesiana cuttings to inoculation with ericoid mycorrhizal fungi. Journal of Horticultural Science and Biotechnology. 80:254-262. Interpretive Summary: Hardwood cuttings of Leucothoe fontanesiana 'Rainbow', treated or untreated with rooting hormone, were inoculated with different ericoid mycorrhizal fungus (EMF) isolates during rooting. Cuttings were placed under mist in a greenhouse and harvested 63, 84, and 109 d after sticking. Cuttings inoculated with two of the three EMF isolates showed better rooting than non-inoculated cuttings 63 d after sticking. However by the end of the experiment, there were no differences in rooting between cuttings in the different inoculation treatments. Only cuttings inoculated with one of the EMF isolates had consistently greater root initiation and weight than non-inoculated cuttings at all harvest dates. Root production on cuttings inoculated with the other two EMF isolates was only greater than non-inoculated cuttings when cuttings had been treated with rooting hormone. In general, roots on inoculated cuttings were less branched and longer than roots on non-inoculated cuttings. Root colonization was positively correlated with root initiation, length, and weight 63 d after sticking, while at the later harvest dates root colonization was only positively correlated with the root weight. The ability of EMF to increase rooting during cutting propagation of easy-to root species, may decrease root production time. EMF-induced increases in root initiation during cutting propagation appear related to specific plant-fungus interactions and to interactions with rooting hormone application. Although there were isolate-specific differences in rooting response, EMF-induced changes in root size and anatomy appear to be time dependant and may influence the function of the new root system relative to water use and nutrient uptake, as well as survival during transplanting. Technical Abstract: Hardwood cuttings of Leucothoe fontanesiana 'Rainbow', treated or untreated with rooting hormone, were inoculated with different ericoid mycorrhizal fungus (EMF) isolates during rooting. Cuttings were placed under mist in a greenhouse and harvested 63, 84, and 109 d after sticking. Cuttings inoculated with two of the three EMF isolates showed better rooting than non-inoculated cuttings 63 d after sticking. However by 109 d, there were no differences in rooting between cuttings from different inoculation treatments. Only cuttings inoculated with one of the EMF isolates consistently increased root initiation and weight at all harvest dates. Root growth on cuttings inoculated with the other EMF isolates was only greater than non-inoculated cuttings when cuttings had been treated with rooting hormone. In general, roots on inoculated cuttings were less branched and longer than roots on non-inoculated cuttings. Root colonization was positively correlated with root initiation, length, and weight 63 d after sticking, while at the later harvest dates root colonization was only positively correlated with the root weight. The ability of EMF to increase rooting during cutting propagation of easy-to root species may decrease root production time. EMF-induced increases in root initiation during cutting propagation appear related to specific plant-fungus interactions and to interactions with rooting hormone application. Although there were isolate-specific differences in rooting response, EMF-induced changes in root size and anatomy appear to be time dependant and may influence the function of the new root system relative to water use and nutrient uptake, as well as survival during transplanting. |
