Rooting response of Prunus wild relative semi-hardwood cuttings to indole-3-butryic acid potassium salt (KIBA)

Authors: JOHNSON, EMILY - University Of California; Preece, John; Aradhya, Mallikarjuna; GRADZIEL, THOMAS - University Of California

Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2019
Publication Date: 12/27/2019
Citation: Johnson, E.P., Preece, J.E., Aradhya, M.K., Gradziel, T. 2019. Rooting response of Prunus wild relative semi-hardwood cuttings to indole-3-butryic acid potassium salt (KIBA). Scientia Horticulturae. 263. https://doi.org/10.1016/j.scienta.2019.109144.
DOI: https://doi.org/10.1016/j.scienta.2019.109144

Interpretive Summary: Wild Prunus germplasm is an important resource for pest and disease resistance traits for the continued improvement of almond and other Prunus rootstocks. Evaluation of resistance in these wild species requires clonal replicates that are traditionally produced by rooting cuttings. Over two consecutive years, leafy cuttings of 20 genotypes of the following wild Prunus species were collected in mid-late May and treated with a 15 s dip in 0, 500, 1000, 2000 or 4000 mg/L of the potassium salt of indole-3-butryic acid (KIBA): P. argentea (one genotype), P. bucharica (two genotypes), P. cerasifera (two genotypes), P. davidiana (two genotypes), P. dulcis (two genotypes), P. kansuensis, P. mira (two genotypes), P. persica (three genotypes including a commercial peach rootstock, ‘Lovell’), P. salicina (two genotypes), and P. tangutica (three genotypes). The cuttings were planted in a perlite-vermiculite medium under intermittent mist and periodically checked for roots. The plum species rooted better than the peach species, and the almond species generally failed to root. The plums rooted best at 2000-4000 mg/L KIBA, although rooting in both P. cerasifera and P. salicina was genotype dependent. The plum cuttings that rooted generally produced from 2 to 14 roots that averaged 0.74 to 1.73 cm long when the cuttings were harvested; one accession produced 60 roots/cutting when treated with 4000 mg/L KIBA. The wild peach species rooted best at 1000-4000 mg/L KIBA, with cuttings of P. kansuensis and P. mira having significantly higher rooting percentages than P. davidiana and P. persica cuttings. All of the wild almond species tested did not root or rooted extremely poorly.

Technical Abstract: Wild Prunus germplasm is an important resource for pest and disease resistance traits for the continued improvement of almond and other Prunus rootstocks. Evaluation of resistance in these wild species requires clonal replicates that are traditionally produced by rooting cuttings. Over two consecutive years, leafy cuttings of 20 genotypes of the following wild Prunus species were collected in mid-late May and treated with a 15 s dip in 0, 500, 1000, 2000 or 4000 mg/L of the potassium salt of indole-3-butryic acid (KIBA): P. argentea (one genotype), P. bucharica (two genotypes), P. cerasifera (two genotypes), P. davidiana (two genotypes), P. dulcis (two genotypes), P. kansuensis, P. mira (two genotypes), P. persica (three genotypes including a commercial peach rootstock, ‘Lovell’), P. salicina (two genotypes), and P. tangutica (three genotypes). The cuttings were planted in a perlite-vermiculite medium under intermittent mist and periodically checked for roots. The plum species rooted better than the peach species, and the almond species generally failed to root. The plums rooted best at 2000-4000 mg/L KIBA, although rooting in both P. cerasifera and P. salicina was genotype dependent. The plum cuttings that rooted generally produced from 2 to 14 roots that averaged 0.74 to 1.73 cm long when the cuttings were harvested; one accession produced 60 roots/cutting when treated with 4000 mg/L KIBA. The wild peach species rooted best at 1000-4000 mg/L KIBA, with cuttings of P. kansuensis and P. mira having significantly higher rooting percentages than P. davidiana and P. persica cuttings. All of the wild almond species tested did not root or rooted extremely poorly.