Due to its economic, social, and ecological potential, Ilex paraguariensis A. St. Hil is considered one of the most important native forestry species in southern Brazil, needing high production of quality plants to supply consumption. Therefore, vegetative propagation is a key technique since it enables plants production with higher standard and genetic quality. Several studies have focused on defining appropriate methods for rooting yerba mate cuttings, even though the overall rooting indexes are not yet considered appropriate. Thus, the objective of this study was to evaluate the rooting, root and aerial vigor of yerba mate cuttings and determine the best cuttings length for formation of clonal plants. Twenty parent trees were pruned and after five months epimoric sprouts were collected to prepare stem cuttings with lengths of 2 ± 0.2 cm, 4 ± 0.2 cm, 6 ± 0.2 cm, 8 ± 0.2 cm, 10 ± 0.2 cm and 12 ± 0.2 cm and diameter of 0.5 ± 0.2 cm. We planted cuttings in plastic boxes filled with substrate based on carbonized yerba mate matchsticks and vermiculite. After 120 days we evaluated the percentage of rooting, number of roots per cutting, average length of the 3 largest roots per cutting, cuttings with callus, cuttings with roots and callus, mortality, sprouts emission, and leaf maintenance. Our results show that rooting and vigor of roots in yerba mate stem cuttings are influenced by cuttings length, being 10 cm cuttings the most efficient for clonal propagation of the species.

No abstract

A germinação de erva-mate tem sido apontada como baixa, irregular e lenta, com diferentes graus de dormência, tornando a produção de mudas um grande desafio. Estudos destinados a esclarecer os principais mecanismos de dormência presentes em sementes de erva-mate são de grande importância, porém, escassos. Diante disso, objetivou-se avaliar os efeitos da secagem na viabilidade e no desenvolvimento embrionário de sementes da espécie. A avaliação do efeito da secagem foi realizada mediante determinação do teor de água, teste de tetrazólio e desenvolvimento embrionário. Para avaliar a tolerância à dessecação, as sementes foram acondicionadas em uma bandeja plástica sem tampa, colocada em prateleira de câmara fria e seca (CFS), regulada com 25 ± 3% de umidade relativa do ar e temperatura de 10 ± 1°C, por 70 dias. A cada sete dias, as sementes foram retiradas da CFS e submetidas ao teste de tetrazólio e à avaliação do teor de água. O desenvolvimento embrionário foi avaliado a partir dos embriões excisados, oriundos do teste de tetrazólio. O teste de germinação foi conduzido no substrato areia, em caixas gerbox, acondicionadas em câmara de germinação regulada a 25°C e fotoperíodo de 12 horas. Das sementes que não foram submetidas à secagem, apenas 8% germinaram, resultado da imaturidade embrionária das sementes recém-colhidas. A secagem por 70 dias promoveu o desenvolvimento embrionário, mas afetou a viabilidade das sementes, sendo recomendada, portanto, sua secagem por até 49 dias para melhorar a germinação e posterior produção de mudas.

Ficus enormis is a native species with great ecological potential, especially for ecosystems restoration. The present study aimed to evaluate the rooting, root and vegetative vigor of Ficus enormis mini-cuttings and to determine its best length for the formation of seedlings. Mini-cuttings were collected from clonal mini-garden, prepared with 2 ± 0.2 cm, 4 ± 0.2 cm, 6 ± 0.2 cm, 8 ± 0.2 cm and 10 ± 0.2 cm of length and diameter of 0.5 ± 0.2 cm. The planting was carried out in plastic boxes filled with commercial substrate based on carbonized rice hulls and coconut fiber, conditioned in a greenhouse. After 45 days, were avaluated the rooting percentage, original leaf maintenance, mini-cuttings with roots and callus percentage, length of the three largest roots/mini-cutting, shoot emission percentage, number of root/mini-cutting and mortality percentage. The results showed that the mini-cuting length did not influenced the rooting percentage, callus and root formation, and root length mean. However, shoot emission, number of root and mortality were influenced by the mini-cutting length.

Due to its economic, social, and ecological potentials, yerba mate can be a source of employment and income in the southern region of Brazil. The objectives of the present study was to (1) quantify the total polyphenols in fresh yerba mate seeds (FS), seeds dehydrated for 70 d (SD), and seeds stratified in sand for 180 d (SS); (2) evaluate the potential germination and growth inhibitory effects of water, ethanol + water (1:1), and ethanol (99%) extracts of yerba seeds (FS, SD, and SS) using lettuce seedlings; and (3) verify the presence of polyphenols in fresh seeds of yerba mate through histochemical methods. In the bioassay, extracts of yerba mate seeds were used in the germination of lettuce seeds. For the histochemical analysis, sections of yerba mate seeds were stained with specific dyes. The results revealed that yerba mate fresh seeds contain higher concentration of phenolic compounds, which decreased in dehydrated seeds, and almost no phenolic compound was observed in stratified seeds. The bioassay results showed that the polyphenols present in the extracts of yerba mate seeds resulted in phytotoxic effect on the roots of lettuce seedlings. The histochemical observations revealed the presence of “lignified rough barrier” and phenolic compounds between the endocarp and endosperm of the yerba mate seeds