Evaluation of the quality of seeds of yerba mate (Ilex paraguariensis A.St.-Hil.) from different mother-plants

Yerba mate seedlings with genetic and physiological quality, high rates of sowing survival and resistance to environmental stresses are necessary for the implantation and establishment of productive plants that will provide quality raw material. However, the production of seedlings, in most cases is carried out from seeds, which are collected from mother-plants with few selection criteria. In this sense, the work aimed to investigate the quality of the seeds of yerba mate after processing by flotation from different mother-plants, by obtaining information about the biometric characterization (longitudinal and transversal measure), water content, a thousand-seed weight, evaluation of the seed integrity and viability through the tetrazolium test. The seeds were collected from 10 mother-plants located in three cities in the yerba-mate region Alto Vale do Taquari - RS state, Brazil. In the integrity assessment, the number of not full (empty and deteriorated) and full (with and without visible embryo) seeds was counted. In the tetrazolium test, the percentage of viable and non-viable seeds was evaluated. The seeds of the different parent plants showed statistical differences for all the variables analyzed. The analysis showed that there are differences related to biometric parameters and water content and, consequently, in the weight of a thousand seeds. Yerba mate shows a varied percentage of empty and deteriorated seeds. The percentage of non-viable seeds is high, which significantly reduces the viability of the seed lot.

Keywords:
Biometry; Thousand seed weight; Tetrazolium test; Seeds viability