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.

Vegetative propagation of mate from shoot cuttings induced by coppicing of selected plants

“…Both mate plants were approximately 18 years old. The stock plants 13SM01 and 13SM05 were previously selected for adventitious rooting competence (Bisognin et al, 2018). They were coppiced to approximately 20 cm from the soil in January 2017.…”

“…After the confection, all cuttings were measured as their diameter in the central portion, using a digital caliper. The cuttings were treated with hydroalcoholic solution (1:1 v/v) of 0 and 3000 mg L -1 IBA, according to the methodology described by Bisognin et al (2018). Cuttings were then cultivated in polyethylene trays with 100 wells, each containing equal proportions of pine barkbased commercial substrate, medium vermiculite, and coarse sand (Pimentel et al 2017).…”

“…Mate presents low multiplication rate due to its recalcitrant behavior of cuttings rooting (Bitencourt, Zuffellato-Ribas, Wendling, & Koehler, 2009), which has restricted the mass production of plantlets of these species. The development of adventitious roots is a complex process which may be affected by multiple factors, including the stock plant (Geiss, Gutierrez, & Bellini, 2009;Bisognin, Lencina, Luz, Fleig, & Gazzana, 2018), collection time of vegetative propagules (Pimentel et al, 2019), phytohormones (Bisognin et al, 2018), and cutting diameter (Stuepp, Wendling, Xavier, & Zuffellato-Ribas, 2018).…”

“…Cuttings of mature shoots do not root or root sporadically, as the hormonal balance of the shoot differs from the hormonal balance during the juvenile state of the plant. In this case, it is necessary to use special techniques to revert to its juvenile state, such as pruning, girdling or coppicing the stock plant, to obtain satisfactory results in vegetative propagation by cuttings (Wendling et al, 2014b;Bisognin et al, 2018).…”

“…Between the phytohormones, the indolebutyric acid (IBA) is the auxin commonly used to promote rhizogenesis, because of its stability and effectiveness compared to other available auxins (Lakehal & Bellini, 2019). Studies with cuttings from shoots induced by coppicing are controversial in terms of IBA application, in one hand showed high cutting mortality (Stuepp et al, 2015a), and in the other hand increased the percentage of rooted cuttings (Bisognin et al, 2018). These different responses to the effect of the phytohormones treatment may be associated with the evaluated genotype (Lakehal & Bellini, 2019), and/or the cutting diameter (Rana & Sood, 2012).…”