ABSTRACT Collema leptosporum was originally included in Collemataceae as part of the Collema fasciculare group, an informal group that also included C. fasciculare, C. papuanorum, and C. uviforme. However, molecular data from C. fasciculare showed that this species belongs to Arctomiaceae, and all species in this informal group were relocated to Arctomia, although no molecular data were generated and analyzed for C. leptosporum, C. papuanorum and C. uviforme. To investigate the phylogenetic relationships of Collema leptosporum, currently Arctomia leptospora, we analyzed three DNA loci and examined morphological and anatomical features of specimens collected near the type locality. Genetic data suggest that this species is not included in Arctomiaceae and should be treated as a new genus in Collemataceae. Hondaria gen. nov. is characterized by having the longest transversely-septate ascospores in the family ((100-)120-175(-200) × 2-4(-5) µm). This study also suggests that the structures characterizing the C. fasciculare group are a result of convergent evolution, since this group includes species from different distantly related species.
ABSTRACT Understanding the genetic structure and diversity of plants is fundamental to their conservation and permits their sustainable use by local communities. The genus Maytenus (Celastraceae) is composed of plants possessing pharmacological and antioxidant properties. However, the genetic and economic properties of the species M. dasyclada, a typical species of Araucaria forests in Brazil and Uruguay, have been little studied. In this work, the genetic structure and diversity of natural populations of M. dasyclada located in unprotected and preserved forest remnants were investigated using RAPD and isozymes markers. The results demonstrated that in areas of preservation, populations of M. dasyclada possess a relatively high degree of polymorphism and high values for Na, Ne, Shannon index, He and Ho, indicating high genetic variability. Moreover, these protected populations are very close to each other and potentially experience significant gene flow. The results presented here highlight the relevance of preservation areas for the conservation of M. dasyclada, and that populations inhabiting these areas could serve as a genetic source for the recovery of populations in regions where genetic diversity has been lost.
Ilex paraguariensis is a native species to South America. Its economic importance is in the use of its leaves and twigs in the processing of a product popularly known as "chimarrão". The aim of this study was to evaluate the correlations between some physico-chemical process parameters in the oxidation of I. paraguariensis leaves oxidation. The leaves of Maté with age 1.0, 6.5 and 12.0 months were subjected to an oxidation process for 3 h under different relative humidity conditions (80, 90 and 99%) at 26°C. The extracts were evaluated using the experimental design techniques to maximize the oxidation conditions for the total polyphenols, antioxidant capacity, water activity and color. The condition of 90% humidity and leaf age 6.5 months resulted in lower lightness and yellow color of the product. Green color was not significantly influenced by the studied parameters. The highest levels of total phenols and antioxidant potential were found when the leaf age was one month and humidity was 90%. Thus, it could be concluded that the air humidity of the chamber and leaf age influenced the oxidation process of the leaves of Maté as well as the antioxidant capacity of the extract obtained.
In Brazil, yerba mate is consumed after processing; however, in Chile and Uruguay, the consumers prefer the cured product, which acquires a yellow color. For that yerba-mate is stored for a period of six months to one year, which increases the cost of the final product for the overseas market. This study evaluated the effect of humidity and temperature in maturation chamber on the time required for the product to get this characteristic. The changes in the color, pH, moisture and water activity were evaluated during the time of storage in different conditions of temperature and humidity. Yerba-mate subjected to higher temperature and humidity showed nearest color of the product submitted to natural storage. The loss of green color was related to the reduction in pH and increase in the moisture of the samples. The higher humidity allowed the mate to reach conditions near to market requirements abroad in approximately 60 days of maturation.