Seasonality and genotype influence on Ilex paraguariensis cuttings rooting and bioactive compounds

Abstract

Yerba mate (Ilex paraguariensis) leaves have many compounds with proven bioactive activity; so, interest and consumption of species' products have increased globally. Here, we used 19 yerba mate genotypes from a provenance and progeny trial, yielding findings that could have significant implications for the species' vegetative propagation and genotype selection, where we indicate some potential genotypes, contributing to yerba mate silviculture and breeding programmes. We evaluated season and genotype effects on rooting of cuttings, contents of bioactive compounds and the influence of these compounds on rhizogenic process. We prepared semi-woody cuttings in four seasons; after 100 days we evaluated rooting variables. Methylxanthines (caffeine and theobromine) and monocaffeoylquinic acids contents were measured using high performance liquid chromatography, from aqueous extract of stock plant mature leaves. There was no correlation between rooting variables and evaluated compounds. Just eight genotypes presented above 70% of rooted cuttings in at least one season. Rooting variables varied between these genotypes and seasons. Caffeine and 5-caffeoylquinic acid (CQA5) significantly contributed to separated genotypes and seasons. CQA5 showed highest levels in spring. Regarding to genotypes, EC22 showed low levels of caffeine in all seasons. The great variation in compounds among genotypes indicates the possibility of breeding for chemical characteristics and raw material production for different products. Our results also indicate the importance of seasons for yerba mate vegetative propagation success and leaf compound contents.