Divergência genética em tomate estimada por marcadores RAPD em comparação com descritores multicategóricos Genetic divergence among tomato accessions using RAPD markers and its comparison with multicategoric descriptors

A estimativa da variabilidade genética existente em um banco de germoplasma é importante não só para a conservação dos recursos genéticos, mas também para aplicações no melhoramento de plantas. O presente trabalho teve como objetivo estudar a divergência genética entre 78 acessos de uma coleção de germoplasma de tomateiro, com base em 74 marcadores RAPD e correlacionar esses resultados àqueles da caracterização morfoagronômica realizada para 27 descritores. Foi utilizado o agrupamento hierárquico UPGMA para analisar os dados, observando-se a formação de 13 grupos. Esses grupos foram correlacionados a cinco descritores (hábito de crescimento, tipo de folha, cor do fruto, número de lóculos e formato do fruto). Alguns grupos apresentaram peculiaridades, a exemplo do grupo IV, que reuniu acessos com frutos no formato de pêra; o grupo VII com acessos resistentes a murcha-bacteriana e o grupo IX, que englobou acessos com folhas do tipo batata. As análises por bootstrap revelaram poucos agrupamentos consistentes. Houve correlação positiva e altamente significativa entre as matrizes geradas pelos 27 descritores qualitativos e pelos marcadores RAPD (t = 14,02). A correlação de Mantel (r = 0,39) foi altamente significativa, porém de baixa magnitude. O baixo valor verificado para esta correlação sugere que ambas as etapas de caracterização (morfoagronômica e molecular) são importantes para um conhecimento mais amplo e melhor discriminação entre os acessos de tomate.<br>The estimation of genetic variability in a germplasm bank is important not only for the conservation of the genetic resources, but also for applications in plant breeding. The genetic divergence among 78 tomato accessions was studied, based on 74 RAPD markers. Also, a correlation between the molecular profile and 27 morphological and agronomic data was performed. Cluster analysis (UPGMA), used to study the data, resulted in 13 groups that were correlated with five descriptors (growth habit, leaf type, fruit color, locule number, and fruit shape). Some groups had particularities, such as group IV that assembled accessions with pear shape fruits; group VII, that clustered accessions with bacterial wilt resistance, and group IX, that gathered accessions with potato leaf type. Bootstrap analysis revealed few consistent clusters. The results showed a positive and significant correlation between the matrixes generated out of qualitative and molecular data (t = 14.02). Mantel's correlation was highly significant, but with a low value (r = 0.39), which suggests that for a wise use of the germplasm bank accessions, both characterization, molecular and morphoagronomic, should be carried out

Ambient Ultrafine Particle Ingestion Alters Gut Microbiota in Association with Increased Atherogenic Lipid Metabolites

Ambient particulate matter (PM) exposure is associated with atherosclerosis and inflammatory bowel disease. Ultrafine particles (UFP, d(p) < 0.1–0.2 μm) are redox active components of PM. We hypothesized that orally ingested UFP promoted atherogenic lipid metabolites in both the intestine and plasma via altered gut microbiota composition. Low density lipoprotein receptor-null (Ldlr(−/−)) mice on a high-fat diet were orally administered with vehicle control or UFP (40 μg/mouse/day) for 3 days a week. After 10 weeks, UFP ingested mice developed macrophage and neutrophil infiltration in the intestinal villi, accompanied by elevated cholesterol but reduced coprostanol levels in the cecum, as well as elevated atherogenic lysophosphatidylcholine (LPC 18:1) and lysophosphatidic acids (LPAs) in the intestine and plasma. At the phylum level, Principle Component Analysis revealed significant segregation of microbiota compositions which was validated by Beta diversity analysis. UFP-exposed mice developed increased abundance in Verrocomicrobia but decreased Actinobacteria, Cyanobacteria, and Firmicutes as well as a reduced diversity in microbiome. Spearman’s analysis negatively correlated Actinobacteria with cecal cholesterol, intestinal and plasma LPC18:1, and Firmicutes and Cyanobacteria with plasma LPC 18:1. Thus, ultrafine particles ingestion alters gut microbiota composition, accompanied by increased atherogenic lipid metabolites. These findings implicate the gut-vascular axis in a atherosclerosis model