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Open access

Franco Tognoni and Roberto Lorenzi

Abstract

Root-stimulating substances have been isolated from tissues of Picea glauca (Moench) Voss. var. albertiana (S. Brown) Sargent cv. Conica. Purification of a methanolic extract by different chromatography systems, concentrated the biological activity mainly in a fraction which upon gas chromatograph–mass spectrographic (GC–MS) analysis indicated the presence of dihydrocholesterol.

Open access

Franco Tognoni and Roberto Lorenzi

Abstract

The acid phase of methanolic extracts of Picea glauca var. albertiana cv. Conica tissue, a difficult-to-root cultivar, had a high content of substances, at Rf 0.9 – 1.0, which inhibited the growth of Avena first internode. Chamaecyparis lawsoniana var. fletcheri, an easy-to-root variety, had a lower content of these substances. The substances stimulated root formation in mung bean cuttings, but no synergistic root-promoting effect was found when they were supplied to mung bean cuttings in the presence of 5 × 10−6M indoleacetic acid (IAA).

The substances at Rf 0.9 – 1.0 showed a dose-response effect over a concn range of 0 to 1.106 g fresh wt. Concn higher than 1.106 g did not further increase the number of roots in either species. An additive effect between extract and IAA was found in Picea at concn below 0.276 g and in Chamaecyparis at concn lower than 0.110 g and higher than 1.106 g fresh wt. The possibility that root initiation may be determined by hormone balance rather than a single substance is discussed.