Abstract Lychnophora pinaster, known as arnica-mineira, is endemic to campos rupestres, at risk of extinction. The present study aimed to characterize the ecogeography and phenolic constituents of 11 L. pinaster populations collected in the mesoregions North, Jequitinhonha, Metropolitan of Belo Horizonte and Campos das Vertentes in the state of Minas Gerais, Brazil. Phenolic constituents were identified and quantified by Ultra-high performance liquid chromatography- mass spectrometry. Lychnophora pinaster occurs in sites at high altitude (700 and 1498 m), annual rainfall of up to 1455 m, soils with low fertility and predominantly loamy texture. Therefore, it can be considered tolerant to acidic soils, with low availability of nutrient. The most abundant substances in all populations were vitexin (18 – 1345 ng/g) and chlorogenic acid (60 – 767 ng/g). The 11 populations formed four groups in relation to the phenolic constituents, with group 1 consisting of the populations of the North Mesoregion (GM, OD) and Jetiquinhonha (DIMa), group 2, the Metropolitan of Belo Horizonte (SRM, NLSC, SM, RPS, CTRA), group 3, the North Mesoregion (ODMa and DI), and group 4, the Campos das Vertentes (CC). Among the populations, only those from the Metropolitan of Belo Horizonte showed correlation of soil properties with phenolic constituents.

This study aimed to present information about the sarsaparilla sold in establishments in the state of São Paulo, Brazil, assess the genetic diversity of Smilax brasiliensis Spreng., Smilacaceae, and examine the growing conditions and productivity of five species of Smilax. The amount of sarsaparilla sold per month at most pharmacies was 0.4 kg on average. Herbal stores and markets sold averages of 9 kg and 8 kg per month, respectively. The weight of the underground biomass of S. fluminensis (188.3 g) is significantly higher than those of other species (28.3-79.6 g). The study demonstrated that high genetic diversity among the Smilax brasiliensis plants belonging to the CPQBA germplasm bank, which was confirmed by the results of the genotyping study that used a SSR marker on S. brasiliensis. The high consumption of sarsaparilla and the low yield of young plants cultivated from seeds with high genetic variability reinforce the need for further studies on the production of Smilax species.

Coconut palms of the Tall group were introduced to Brazil from the Cape Verde Islands in 1553. The present study sought to evaluate the genetic diversity among and within Brazilian Tall coconut populations. Samples were collected of 195 trees from 10 populations. Genetic diversity was accessed by investigating 13 simple sequence repeats (SSR) loci. This provided a total of 68 alleles, ranging from 2 to 13 alleles per locus, with an average of 5.23. The mean values of gene diversity (He) and observed heterozygosity (Ho) were 0.459 and 0.443, respectively. The genetic differentiation among populations was estimated at θ = 0.1600 and the estimated apparent outcrossing rate was t a = 0.92. Estimates of genetic distances between the populations varied from 0.034 to 0.390. Genetic distance and the corresponding clustering analysis indicate the formation of two groups. The first consists of the Baía Formosa, Georgino Avelino, and São José do Mipibu populations and the second consists of the Japoatã, Pacatuba, and Praia do Forte populations. The correlation matrix between genetic and geographic distances was positive and significant at a 1% probability. Taken together, our results suggest a spatial structuring of the genetic variability among the populations. Geographically closer populations exhibited greater similarities.

Podridão de carvão, causada por Macrophomina phaseolina é uma das mais importantes doenças da soja. Variabilidade genética tem sido observada entre isolados. Entretanto, o efeito de especialização deste fungo, de acordo com a planta hospedeira, não foi ainda relatado. Isolados de soja, milho e girassol foram avaliados, em inoculações cruzadas, quanto à capacidade de formação de microesclerócios em raiz. A maior e menor produção significativa de microesclerócios (P<0.005) foram observadas em raízes de soja (863 microesclerócios/g de raiz) e girassol (578 microesclerócios/g de raiz), respectivamente, independente da origem do isolado. Além disso, estudou-se a variabilidade de isolados do fungo, obtidos de sistemas de rotação de culturas estabelecido há 20 anos utilizando-se RAPD. Oitenta e nove isolados, oriundos de cinco populações foram coletados em amostras de solo de quatro sistemas de rotação e uma amostra de solo virgem. Sete agrupamentos foram observados com 85% de similaridade. As análises indicaram que M. phaseolina é uma espécie com alta variabilidade genética com forte efeito do sistema de rotação. AMOVA foi realizada com os dados de RAPD. Da variabilidade genética total, 21% (P<0.0001) foi explicada pelas diferenças entre populações e, 79% foi explicada por diferenças dentro das populações ( Φst = 0.2110; P<0.0001). A média do coeficiente de diferenciação gênica (G ST) estimada entre as cinco populações foi de 27%, similar aos resultados da AMOVA ( Φst= 0.2110). A diversidade genética total mostrou que as cinco populações têm alto grau de variabilidade (H T =0.3484). Os resultados sugerem que a diferenciação genética de M. phaseolina pode ser alterada pela rotação de culturas.

Charcoal rot, caused by Macrophomina phaseolina, is one of the most important diseases of soybean. Genetic variability among soybean isolates has been observed but the effect of host specialization on genetic variability has not been reported. In this work, isolates from soybean, corn and sunflower were evaluated based on cross inoculations and number of microsclerotia/g of roots. The highest and lowest significant (P<0.005) production of microsclerotia was obtained in soybean (863 microsclerotia/g of roots) and sunflower (578 microsclerotia/g of roots), respectively, regardless of the origin of the isolate. Additionally, the effect of a 20-year crop rotation on genetic variability based on RAPD was studied. Eighty-nine isolates from five populations were obtained from soil samples under four crop rotation systems and an uncropped soil. Seven clusters were obtained considering a similarity level of 85%. Analysis indicated that M. phaseolina is a highly diverse species and also revealed a strong effect of the rotation system on genetic diversity. AMOVA was conducted for the RAPD data. From the total genetic variability, 21% (P<0.0001) could be explained by the differences between populations while 79% could be explained by differences within populations ( Φst = 0.2110; P<0.0001). The mean coefficient of gene differentiation (G ST) estimated among the five populations indicated 27% of differentiation between populations similar to the AMOVA results where Φst= 0.2110. Total gene diversity estimated indicated high levels of variability (H T =0.3484). Results suggest that genetic differentiation of M. phaseolina can be altered by crop rotation.

A mutagênese tem sido tradicionalmente usada para gerar variabilidade genética em plantas ornamentais. Recentemente, tornou-se uma ferramenta poderosa na descoberta e análise da função gênica em genética reversa. Este trabalho objetivou comparar a eficiência da mutagênese física e química na geração de populações mutantes de petúnia. O dano genômico foi avaliado indiretamente por características de desenvolvimento de plântulas após o tratamento com doses de radiação gama de 0, 20, 40, 60, 80 e 100 Gy e do agente alquilante etil-metanossulfonato (EMS) de 0; 0,05; 0,1; 0,15; 0,2 e 0,25% (v/v). Radiação gama e EMS causaram danos ao desenvolvimento e reduziram a viabilidade das plântulas derivadas das sementes tratadas. As maiores doses de mutagênico diminuíram o número de plantas com folhas primárias aos 15 dias após a semeadura (DAS) em aproximadamente 44% e reduziram as taxas de sobrevivência a 55% (gama) e 28% (EMS) em relação aos controles. A redução na altura das plântulas foi proporcional ao aumento das dosagens de EMS, enquanto 40 e 60 Gy de radiação gama provocaram a redução mais significativa na altura de plantas. Abordagens de genética reversa requerem danos genômicos moderados, que permitam alta saturação de alelos mutantes com pequena redução no número de plantas viáveis, relacionados ao parâmetro biológico DL50, dosagem de mutagênico necessária para eliminar metade da população. Este valor correspondeu a 100 Gy de radiação gama e 0,1% de EMS. Os tratamentos foram empregados para a geração de populações mutantes de petúnia (M1 e M2) e novos mutantes morfológicos foram isolados.

Traditionally, mutagenesis has been used to introduce novel genetic variability in ornamental crops. More recently, it has become a powerful tool in gene discovery and functional analyses in reverse genetics approaches. The present work aimed to compare the efficiency of physical and chemical agents in generating mutant populations of petunia. We have indirectly evaluated the genomic damage by analyzing developmental characteristics of the plantlets derived from treated seeds employing gamma radiation at 0, 20, 40, 60, 80 and 100 Gy and the alkylating agent ethyl-methanesulfonate (EMS) at 0, 0.05, 0.1, 0.15, 0.2 and 0.25% (v/v). Gamma rays and EMS caused developmental defects and decreased seedling viability in plants obtained from the mutagenized seeds. High mutagen doses reduced in approximately 44% the number of plants with primary leaves at 15 days after sowing (DAS) and decreased seedling survival rates to 55% (gamma) and 28% (EMS), in comparison to untreated controls. Seedling height decrease was proportional to increasing EMS dosage, whereas 40 and 60 Gy of gamma irradiation caused the most significant reduction in height. Moderate DNA damage allowing a high saturation of mutant alleles in the genome and the generation of viable plants for reverse genetics studies was correlated to the biological parameter LD50, the dose required to kill half of the tested population. It corresponded to 100 Gy for gamma radiation and 0.1% for EMS treatment. The optimized mutagen treatments were used to develop petunia mutant populations (M1 and M2) and novel morphological mutants were identified.