Abstract

In order to better understand the physiological and technical aspects of yerba mate vegetative propagation, the present study sought to evaluate the rhizogenic capacity of apical and basal mini-cuttings from different genotypes (named A3, A7, F1 and F2) and the possible relationships between rooting and specific biochemical and anatomical aspects of the species. After 90 days under greenhouse conditions, the following variables were assessed: mini-cuttings rooting percentage, number of roots, roots length, callogenesis, mortality, sprouting and leaf retention. Mini-cuttings samples were collected at the time of planting and after 90 days in the rooting environment in order to investigate the aspects related to stem and roots anatomy as well as the levels of phenolic compounds (PC) and the activities of peroxidade (POD) and polyphenol oxidase (PPO) enzymes. Genotype A3 presented the best rooting performance (65.6% rooting) while F2 had the lower rooting rates (24.5%). Apical and basal mini-cuttings did not differ regarding rooting associated variables. Both mini-cuttings types and the four genotypes showed identical anatomical features, with no evident mechanical barriers to roots emission. Despite specific differences on POD, PPO and PC activities/contents as influenced by topophysis, genotype and/or their interaction, no direct relationship could be stated between the biochemical features at the time of planting or 90 days after and the overall rooting performance of yerba mate the mini-cuttings. The present study not only provides valuable information on technical aspects of yerba mate propagation but also presents insights in the physiological and anatomical traits of adventitious rhizogenesis in this species.

Graphic abstract

中文翻译：

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巴拉圭冬青顶端和基部小型扦插不定根发生的生化和解剖学特征

摘要

为了更好地了解马黛茶营养繁殖的生理和技术方面，本研究试图评估来自不同基因型（命名为 A3、A7、F1 和 F2）的顶端和基部微型扦插的生根能力以及它们之间可能的关系。该物种的生根和特定的生化和解剖学方面。在温室条件下 90 天后，评估以下变量：小插条生根百分比、根数、根长度、愈伤组织、死亡率、发芽和叶片保留。在种植时和在生根环境中 90 天后收集小插条样品，以研究与茎和根解剖相关的方面以及酚类化合物 (PC) 的水平和过氧化物 (POD) 的活性和多酚氧化酶 (PPO) 酶。基因型 A3 表现出最好的生根性能（65.6% 生根），而 F2 具有较低的生根率（24.5%）。根尖和基部小插条在生根相关变量方面没有差异。微型插条类型和四种基因型都显示出相同的解剖特征，对根部发射没有明显的机械障碍。尽管受地形、基因型和/或其相互作用的影响，POD、PPO 和 PC 活性/内容存在特定差异，种植时或 90 天后的生化特征与马黛茶迷你插条的整体生根性能之间没有直接关系。本研究不仅提供了马黛茶繁殖技术方面的宝贵信息，而且还提供了对该物种不定根发生的生理和解剖特征的见解。

图形摘要