Diversidade química e genética de populações naturais de Lychnophora pinaster Mart.
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Data
2020-02-27
Autores
Marques, Ana Paula da Silva [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Lychnophora pinaster Mart. (Asteraceae) é uma espécie de ocorrência restrita ao Estado de Minas Gerais e utilizada pela população local por suas propriedades anti-inflamatória e analgésica. O uso indiscriminado pela população e destruição de seu habitat contribuíram para que a espécie entrasse em risco de extinção. Estudos de populações de L.pinaster oriundas do sul e do norte do estado de Minas Gerais reportam diferentes composições de seus óleos essenciais e níveis de diversidade genética, sendo necessários estudos de maior abrangência geográfica que permitam sua caracterização em diversas regiões do estado. Diante disso, este estudo objetivou avaliar a composição química dos óleos essenciais e diversidade genética de populações de Lychnophora pinaster Mart. coletadas em diferentes regiões de Minas Gerais. As populações avaliadas nos estudos químicos são oriundas de duas regiões: Diamantina (DIMa), Olhos D’Àgua (OD) e Grão Mogol (GM), da região Norte de Minas Gerais; e três da Região Metropolitana de Belo Horizonte, Caeté/Rio Acima (CTRA), Nova Lima/Serra da Calçada (NLSC) e Serra da Moeda (SM). Os óleos essenciais foram extraídos por hidrodestilação, a composição química analisada por CG-EM e CGxCG-EM e os resultados avaliados por métodos quimiométricos. Análises de solos revelaram diferenças entre os solos das populações. DIMa e SM apresentaram os maiores rendimentos dos óleos essenciais (ambas 0,12%), enquanto o menor foi o de NLSC (0,04%). Não foi detectada diferença de rendimento em função da região. Os óleos essenciais apresentarm divergência na composição química em função da população. Para a região norte, dentre as substâncias majoritárias estão o α-pineno (12%) GM; 14-acetoxi-α-humuleno, (21,9%) para DIMa e 14-hidroxi-4,5-dehidro-cariofileno e esquamulosona (9,13% e 8,30%, respectivamente) para OD. Para a Região Metropolitana de Belo Horizonte as substâncias com maior abundância foram; 1,7-diepi-α-cedrenal (6,46%), (Z)-nerolidol (12,60%) em CTRA. Entre regiões, o 14-hidroxi-α-humuleno também foi majoritário para GM (35,95%), DIMa (13,39%) e NLSC (56,33%). DIMa, OD e NLSC se mostraram próximas quimicamente, apesar de pertencerem a diferentes regiões do estado, distantes em 273km. As populações GM, SM e CTRA não demonstraram similaridade química entre si ou com as demais. Estes resultados, em conjunto com os da literatura, sugerem a ocorrência de quimiotipos em função da região e entre populações. As análises genéticas demonstram que as populações de L.pinaster apresentaram déficit de heterozigotos, com exceção de AB, para qual as heterozigosidades esperada e observada foram iguais. As análises de componentes 2 principais e discriminante resultaram em um agrupamento genético das populações em função da região. A distância geográfica e a endogamia nas populações apresentaram efeito sobre as distâncias genéticas encontradas, contribuindo para seu aumento. As populações não exibiram um padrão de agrupamento em função da região e se mostraram estruturadas, com Campos das Vertentes formando um único grupo e exibindo compartilhamento dos SNPs somente entre si. A região metropolitana de Belo Horizonte não apresentou agrupamento das populações, permanecendo isoladas entre si, enquanto na região norte formaram-se dois grupos, um de GM e OD e outro de DIMa. Os resultados encontrados para as análises genéticas vão ao encontro das características químicas dos óleos essenciais das populações.
Lychnophora pinaster Mart. (Asteraceae) is a species restricted to the State of Minas Gerais and used by the local population for its anti-inflammatory and analgesic properties. The indiscriminate use by the population and the destruction of its habitat contributed to the species becoming at risk of extinction. Studies of L. pinaster populations from the south and north of the state report different compositions of their essential oils and levels of genetic diversity, requiring studies of greater geographic scope that allow their characterization in several regions of the state. Given this scenario, this study aimed to evaluate the chemical composition of essential oils and genetic diversity of populations of Lychnophora pinaster Mart. collected in different regions of Minas Gerais. The populations evaluated in the chemical studies come from two regions: Diamantina (DIMa), Olhos D’Àgua (OD) and Grão Mogol (GM), from the northern region of Minas Gerais; and three from the Metropolitan Region of Belo Horizonte, Caeté/Rio Acima (CTRA), Nova Lima/Serra da Calçada (NLSC) and Serra da Moeda (SM). The essential oils were extracted by hydrodistillation, the chemical composition analyzed by CG-EM and CGxCG-EM and the results evaluated by chemometric methods. Soil analyzes revealed differences between the populations' soils. DIMa and SM showed the highest yields of essential oils (both 0.12%), while the lowest was that of NLSC (0.04%). No difference in yield was detected depending on the region. Essential oils differ in chemical composition depending on the population. For the northern region, major substances include α-pinene (12%) GM; 14-acetoxyα-humulene, (21.9%) for DIMa and 14-hydroxy-4,5-dehydro-karyophylene and squamulosone (9.13% and 8.30%, respectively) for OD. For the Metropolitan Region of Belo Horizonte, the most abundant substances were; 1,7-diepi-α-cedrenal (6.46%), (Z) -nerolidol (12.60%) in CTRA. Among regions, 14- hydroxy-α-humulene was also the majority for GM (35.95%), DIMa (13.39%) and NLSC (56.33%). DIMa, OD and NLSC were shown to be chemically close, despite belonging to different regions of the state, 273km apart. The GM, SM and CTRA populations did not show chemical similarity to each other or to the others. These results, together with those in the literature, suggest the occurrence of chemotypes depending on the region and between populations. Genetic analyzes demonstrates that L. pinaster populations showed a deficit of heterozygotes, with the exception of AB, for which the expected and observed heterozygosities were equal. The principal component and discriminant analyzes resulted in a genetic grouping of populations according to the region. Geographic distance 4 and inbreeding in populations had an effect on the genetic distances found, contributing to its increase. The populations did not exhibit a pattern of grouping according to the region and were shown to be structured, with Campos das Vertentes forming a single group and exhibiting SNPs sharing only among themselves. The metropolitan region of Belo Horizonte did not present a group of populations, remaining isolated from each other, while in the northern region two groups were formed, one of GM and OD and the other of DIMa. The results found for the genetic analyzes are in agreement with the chemical characteristics of the essential oils of the populations.
Lychnophora pinaster Mart. (Asteraceae) is a species restricted to the State of Minas Gerais and used by the local population for its anti-inflammatory and analgesic properties. The indiscriminate use by the population and the destruction of its habitat contributed to the species becoming at risk of extinction. Studies of L. pinaster populations from the south and north of the state report different compositions of their essential oils and levels of genetic diversity, requiring studies of greater geographic scope that allow their characterization in several regions of the state. Given this scenario, this study aimed to evaluate the chemical composition of essential oils and genetic diversity of populations of Lychnophora pinaster Mart. collected in different regions of Minas Gerais. The populations evaluated in the chemical studies come from two regions: Diamantina (DIMa), Olhos D’Àgua (OD) and Grão Mogol (GM), from the northern region of Minas Gerais; and three from the Metropolitan Region of Belo Horizonte, Caeté/Rio Acima (CTRA), Nova Lima/Serra da Calçada (NLSC) and Serra da Moeda (SM). The essential oils were extracted by hydrodistillation, the chemical composition analyzed by CG-EM and CGxCG-EM and the results evaluated by chemometric methods. Soil analyzes revealed differences between the populations' soils. DIMa and SM showed the highest yields of essential oils (both 0.12%), while the lowest was that of NLSC (0.04%). No difference in yield was detected depending on the region. Essential oils differ in chemical composition depending on the population. For the northern region, major substances include α-pinene (12%) GM; 14-acetoxyα-humulene, (21.9%) for DIMa and 14-hydroxy-4,5-dehydro-karyophylene and squamulosone (9.13% and 8.30%, respectively) for OD. For the Metropolitan Region of Belo Horizonte, the most abundant substances were; 1,7-diepi-α-cedrenal (6.46%), (Z) -nerolidol (12.60%) in CTRA. Among regions, 14- hydroxy-α-humulene was also the majority for GM (35.95%), DIMa (13.39%) and NLSC (56.33%). DIMa, OD and NLSC were shown to be chemically close, despite belonging to different regions of the state, 273km apart. The GM, SM and CTRA populations did not show chemical similarity to each other or to the others. These results, together with those in the literature, suggest the occurrence of chemotypes depending on the region and between populations. Genetic analyzes demonstrates that L. pinaster populations showed a deficit of heterozygotes, with the exception of AB, for which the expected and observed heterozygosities were equal. The principal component and discriminant analyzes resulted in a genetic grouping of populations according to the region. Geographic distance 4 and inbreeding in populations had an effect on the genetic distances found, contributing to its increase. The populations did not exhibit a pattern of grouping according to the region and were shown to be structured, with Campos das Vertentes forming a single group and exhibiting SNPs sharing only among themselves. The metropolitan region of Belo Horizonte did not present a group of populations, remaining isolated from each other, while in the northern region two groups were formed, one of GM and OD and the other of DIMa. The results found for the genetic analyzes are in agreement with the chemical characteristics of the essential oils of the populations.
Descrição
Palavras-chave
Óleos essenciais, Genética de populações, Plantas medicinais, Metabólitos especializados, Essential oils, Population genetics, Medicinal plants, Specialized metabolites