Vegetative propagation of Grindelia chiloensis (Asteraceae)

WASSNER,D; RAVETTA, D.A.

Industrial Crops and Products

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2000 vol. 11 p. 7 - 10

0926-6690

Grindelia chiloensis (Asteraceae) is a shrub native to Patagonia, Argentina, in the process of domestication as asource of resin to complement rosin production by pines. Vegetative propagation to multiply selected genotypes hasproduced breakthroughs in the cultivation of new crops like jojoba (Simmondsia chinesis). The only available way topropagate Grindelia is by transplanting seedlings or direct seeding. Both alternatives rely on selected varieties, aprocess that takes several years in an open-pollinated, self-incompatible species. The objective of this study was togenerate a protocol for the vegetative propagation of G. chiloensis. Two experiments were carried out to evaluate theeffect of the mother plant, the source of the cutting (apical or basal), and the concentration of indole butyric acid(IBA) on rooting success and root and above-ground biomass accumulation. A third study was conducted to evaluatethe field survival of the propagated plants. Stems (15 cm) were cut from several mother plants growing in the fieldand stored in plastic containers with ice for about 4 h. Two types of cuttings were prepared from each stem: apical(upper 6–8 nodes) and basal (lower 6–8 nodes). A commercially available IBA source (Hormex, rooting powder,Brooker Chemical, Hollywood, CA) was used at six concentrations (0.1, 0.3, 0.8, 1.6, 3.0, and 4.5%). The cuttingswere dipped in water and in the plant regulator and planted into speedlings filled with peat moss, vermiculite andsand (1:1:1, v:v:v). The speedlings were placed under a mist system in a greenhouse at 25°C. Rooting success and rootweight were evaluated 30 days after the experiments were started. The position of the cutting, the IBA concentration,and the mother plant affected rooting success. None of the basal cuttings rooted even with IBA treatment. For theapical cuttings, IBA concentrations between 0.1 and 1.6% resulted in more than 64% rooting and the largest rootmass (PB0.01). The control cuttings (0% IBA) did not produce adventitious roots. Accessions differed on rootingsuccess. Transplanting survival varied between 25 and 100% depending on the clone. Vegetative propagation willallow the multiplication of Grindelia clones selected for their productive superiority. Traits such as resin content andcomposition, and regrowth after harvest are important characteristics to select for. © 2000 Elsevier Science B.V. Allrights reserved.Keywords: Crop establishment; New crops; Arid lands; Resin; Shrubs