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Variabilidade genética e de compostos voláteis e semi-voláteis em populações nativas de llex paraguariensis (St. Hil.) do Brasil, visando a conservação da espécie
(Universidade Federal de São Carlos, 2003-04-29) Cansian, Rogério Luis; Echeverrigaray, Sergio; https://lattes.cnpq.br/5630031784004533
Ilex paraguariensis, known as mate tea, is processed in many ways and commercialized as tea, soluble powder, essences, and processed leaves for preparation of mate tea without sugar ( chimarrão and tererê ). Aiming the conservation of this species, this work studied the intra- and interpopulational genetic variabilities of I. paraguariensis and its volatiles and semi-volatiles composition in 20 populations inside the area of incidence of this species in Brazil. Paternity tests were also performed to identify a favorable crossing for obtaining lineages with the characteristics of interest, reducing then the impact of extractive harvest on the native plants. Genetic variability of I. paraguariensis analyzed by RAPD markers (Random Amplified Polymorphic DNA) is lower to the reported variability in other dioic arboreal species. Intrapopulational variability is higher than interpopulational in this species. In intra and interpopulational studies alleles with the same allele sequence were identified, as well as alleles with very different sequences, what evidences the incidence of genetic flux among populations that are close geographically, but with alleles specific of each population. The environmental differences taken into account were not enough to explain genetic and chemical differences found among the populations. These results show the possibility of influences of microenvironmental factors and non-analyzed genes in the analyzed chemical composition of mate tea leaves. The population of Ponta Porã, geographically separated from the others, proved to be genetically distinct. Species-specific fragments were obtained for I. paraguariensis, I. dumosa and I. theezans. However, more studies for confirmation and utilization of such fragments must be carried out. The differences in the volatiles and semivolatiles composition among the populations turned their separation possible, and may be useful for identification and inclusion of genotypes, superior in specific compounds, in germoplasm collections. For conservation of this species in germoplasm collections ex situ, material collecting must be based on genetic analysis, as well as on geographical distribution, due to the higher intrapopulational variability and occurrence of rare alleles in the species. The RAPD technique may be used for paternity identification, mainly in arboreal species, making possible to obtain genetic improvement by performing controlled crossings. Based on these results, it was possible the discussion concerning the conservation aspects of this species.
Variabilidade genética e de compostos voláteis e semi-voláteis em Maytenus ilicifolia Mart. ex Reiss
(Universidade Federal de São Carlos, 2003-04-29) Mossi, Altemir José; Echeverrigaray, Sergio; https://lattes.cnpq.br/5630031784004533
Genetic and chemical variability of Maytenus ilicifolia Maytenus ilicifolia is a native plant of Southern Brazil commonly used as a popular medicine for indigestion, gastritis and ulcers. The large use of this plant has increased the degradation of the species, and thus it is presently included in FAO´s list for priority species for studying and conservation in South America. In this context, this work aimed to contribute with studies that help the conservation of this species. Initially, a survey in herbaria and in the field was performed to identify the incidence and distribution of the genus Maytenus in the State of Rio Grande do Sul. Three new species (M. glaucenscens Reiss, M. gonoclada Mart. and M. robusta Reiss) were found in this State. The genetic variability study of three populations showed that the intrapopulational variation (variance from 0.102 to 0.140) is higher than the interpopulational (variance between 0.076 and 0.099%). The three populations analyzed grouped themselves with low significance level and 7.6% of the present alleles are rare. The genetic variability study involving 18 native populations of Maytenus ilicifolia, Maytenus aquifolia and Maytenus evonymoidis demonstrated that the species may be separated with 100% of confidence, and that M. ilicifolia and M. aquifolia are genetically more similar. The populations of Maytenus ilicifolia analyzed formed three groups with low confidence levels. Group I included the populations of Ponta Porã, group II the populations of Santana do Livramento, Vale Verde, Canguçu and Unistalda, and group III was formed by the other 13 populations. A similarity in the genetic and environmental grouping of such species was observed. The chemical characterization was performed by gas chromatography of the extracts obtained with high pressure CO2. An increase in the yield of extract was obtained when the temperature of extraction as well as the solvent density were increased. The compounds that presented higher yield in the first fractions were dodecanoic acid, geranyl acetone, phytol, squalene, vitamin E and stigmast-5-enol. The compounds friedelan-3-ol and friedelin were extracted in higher yields in the following fractions. The chemical variability study of the volatile and semi-volatile compounds of populations of M. ilicifolia showed a yield of extract (0,488 a 0,976 %) significantly different between the populations. In addition no relation between the chemical and environmental or between the chemical and genetic grouping could be established.