Genetic diversity of <i>Lippia rotundifolia</i> Cham. in Minas Gerais, Brazil

Abstract

Lippia rotundifolia is an aromatic species, endemic from Campos rupestres and isolated by mountains. We aimed with the research to study the genetic variability of chá-de-pedestre (Lippia rotundifolia Cham.) with natural occurrence in ten places of the State of Minas Gerais, from molecular markers of ISSR type. The places of collection were: Parque Estadual de Serra Nova; Parque Estadual Veredas do Peruaçu; Abóboras community; Gigante community; edge of Rio do Peixe; environmental preservation area of Olhos d´água; private property in Joaquim Felício; Parque Estadual do Rio Preto; São Gonçalo do Rio das Pedras and brook of Rio Tigre. After the establishment of the extraction and amplification of DNA fragments with primers ISSR, an array of genetic distance was built. From this matrix, we analyzed the genetic diversity index as the allelic frequency (Na and Ne), Shannos´s index (H´), polymorphism (PLP), heterozygosity (He) and gene flow (Nm). The result showed higher genetic variability within the population (93%). The genetic diversity index was low (He = 0.132; H´= 0.214; Na = 1.111; Ne = 1.183; PLP = 56.67%). In general the species have low genetic diversity. The greatest diversity in populations occurred with an average temperature of 20°C. The Rio Tigre showed higher genetic distance and isolation.

Growth and essential oil content of accessions of Lippia rotundifolia in Minas Gerais, Brazil

“…The oil yield of the RTI and RPE accessions was similar, being of 0.40 and 0.54%, respectively, while that of the other accessions was above 0.60%, ranging from 0.61 to 0.91% for ODA, GIG, and PRP. This compatibility in oil content is due to the genetic similarity observed through the molecular structure analysis, in which these accessions were gathered in the same group by genetic proximity (Meira et al, 2019b). According to Jannuzzi et al (2011), a yield of 0.5% essential oil is considered satisfactory for L. alba.…”

“…Besides phenology, the diversity among genotypes may also explain the differences found in the evaluated parameters (Hartl & Clark, 2010), especially since the environmental factors were controlled under greenhouse conditions. Likewise, Tavares et al (2005) inferred that the differences between plants are due to the plasticity expressed by the used accessions, since, in a natural environment, the species occurs under different climatic conditions, such as altitude ranging from 690 to 1,020 m, precipitation from 700 to 1,600 mm, and temperature from 18 to 24°C (Table 1) (Meira et al, 2019b). Moreover, considering that the evaluated species has a low nutritional requirement and grows in soil with low to very low levels of physicochemical attributes, high acidity, and clayey texture (Ribeiro et al, 1999), it is believed that the cultural treatments applied in the present work were efficient to obtain the observed results.…”

“…Even though the species is grown mostly under protected cultivation, many factors can still affect its productive performance. Among them are edaphic and climatic conditions, besides the genetic factor, which allows plants to respond differently to the same cultivation conditions, at a same site, due to the phenotypic plasticity caused by changes in gene expression (Kumar et al, 2010;Meira et al, 2019b). This can interfere in the phenology of the species, as well as in the product obtained after harvest (Souza et al, 2007;Hartl & Clark, 2010;Souza et al, 2014).…”