Rooting competence of mini-cuttings of Cabralea canjerana clones in different seasons

ABSTRACT: The objectives of this research were to evaluate the rooting competence of mini-cuttings throughout the four seasons and to estimate the adventitious rooting time of canjerana clones. A clonal mini-garden was established with 11 clones in a closed hydroponic system. Evaluations were performed throughout the four seasons for the number of mini-cuttings produced per mini-stump, percentage of survival and rooting of mini-cuttings, number of roots, average root length, and number of rooted mini-cuttings per mini-stump. Data were submitted to analysis of variance and means were compared. A rooting curve was estimated for clones 10SM05, 12SMI25, and 12SMI43 that exhibited high competence for adventitious rooting. Our results indicated that canjerana clones can be selected for adventitious rooting competence of mini-cuttings during different seasons, and that canjerana mini-cuttings should be cultivated for 63 days in a rooting chamber.

ADVENTITIOUS ROOTING COMPETENCE AND RESCUE OF ADULT MATE PLANTS BY CUTTINGS

ABSTRACT The competence of adult plants of mate (Ilex paraguariensis St. Hil.) to undergo adventitious rooting is essential to their vegetative rescue by cuttings. This study aimed to evaluate the adventitious rooting competence of adult mate plants, and then rescue these plants by making cuttings from epicormic shoots induced in different trunk positions. The percent survival and rooting of cuttings from epicormic shoots induced by girdling in seven adult plants were evaluated. The two stock plants whose cuttings had the highest rooting competence were further pruned and girdled to evaluate the effect of the position of epicormic shoots on their adventitious rooting competence. The potential success of rescuing of the same adult plants was also studied with cuttings of epicormic shoots induced by coppicing. The shoots were sectioned in single-bud cuttings, either treated with 3,000 mg L-1 indolebutyric acid or untreated, and then cultivated in a humid chamber for 60 days, and then the percent survival and rooting of cuttings was evaluated. In conclusion, we found that it is possible to rescue adult mate plants by cuttings from epicormic shoots induced by pruning, girdling, or coppicing. The adventitious rooting competence of cuttings differs among adult mate plants, and depends on the position of the epicormic shoots on the trunk from which epicormic shoots are collected.

Lignification Associated with Decreased Adventitious Rooting Competence of English Ivy Petioles

English ivy (Hedera helix L.) was used to study the relationship between lignin accumulation and adventitious rooting. Juvenile-phase and three chronological ages of mature-phase petioles were collected from clonal stock plants, analyzed for quantity of vascular lignin, and placed in an in vitro rooting assay. Rooting competence was determined by observing the number of roots formed per petiole. The number of roots per petiole differed significantly between juvenile-phase and mature-phase petioles. Lignin accumulation increased during petiole growth and development with chronologically older mature-phase petioles having the greatest amounts of lignin. There was a negative correlation between lignin accumulation and adventitious rooting competence.