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Background: Plant genomes are rich in repetitive sequences, and transposable elements (TEs) are the most accumulated of them. This mobile fraction can be distinguished as Class I (retrotransposons) and Class II (transposons). Retrotransposons that are transposed using an intermediate RNA and that accumulate in a "copy-and-paste" manner were screened in three genomes of peppers (Solanaceae). The present study aimed to understand the genome relationships among Capsicum annuum, C. chinense, and C. baccatum, based on a comparative analysis of the function, diversity and chromosome distribution of TE lineages in the Capsicum karyotypes. Due to the great commercial importance of pepper in natura, as a spice or as an ornamental plant, these genomes have been widely sequenced, and all of the assemblies are available in the SolGenomics group. These sequences were used to compare all repetitive fractions from a cytogenomic point of view. Results: The qualification and quantification of LTR-retrotransposons (LTR-RT) families were contrasted with molecular cytogenetic data, and the results showed a strong genome similarity between C. annuum and C. chinense as compared to C. baccatum. The Gypsy superfamily is more abundant than Copia, especially for Tekay/Del lineage members, including a high representation in C. annuum and C. chinense. On the other hand, C. baccatum accumulates more Athila/Tat sequences. The FISH results showed retrotransposons differentially scattered along chromosomes, except for CRM lineage sequences, which mainly have a proximal accumulation associated with heterochromatin bands. Conclusions: The results confirm a close genomic relationship between C. annuum and C. chinense in comparison to C. baccatum. Centromeric GC-rich bands may be associated with the accumulation regions of CRM elements, whereas terminal and subterminal AT-and GC-rich bands do not correspond to the accumulation of the retrotransposons in the three Capsicum species tested.

Estimating the genetic variability in germplasm collections is important not only for conserving genetic resources, but also for plant breeding purposes. However, generating a large number of different categories data (qualitative and quantitative) often complicate the analysis and results interpretation, resulting in an incomplete distinction of accessions. This study reports the characterization and evaluation of 14 pumpkin (Cucurbita moschata) accessions collected from farms in the northern region of Rio de Janeiro state. Genetic diversity among accessions was also estimated using qualitative and quantitative variables considering joint analysis. The plants were grown under field conditions in a randomized block design with three replications and six plants per plot. Eight qualitative traits (leaf size; seed shape; seed color; color of the fruit pulp; hollow; fruit shape; skin color, and fruit skin texture) and eight quantitative traits (fruit weight; fruit length; fruit diameter; soluble solids, 100 seed weight, and wall thickness measured in the middle and in the lower stem) were evaluated. The data were analyzed considering the Gower distance, and cluster analysis was performed using unweighted pair group method with arithmetic mean (UPGMA). Variability among accessions was observed considering morphoagronomic data. The Gower distance together with UPGMA cluster allowed for good discrimination between accessions in the groups, demonstrating that the simultaneous analysis of qualitative and quantitative data is feasible and may increase the understanding of the variation among accessions. Key words: Cucurbita moschata. Gower distance. Morphoagronomic descriptors. Multivariate analyses. ResumoA estimativa da variabilidade genética em banco de germoplasma é importante não só para conservação dos recursos genéticos, mas também para sua utilização no melhoramento de plantas. Entretanto, a geração de um grande número de variáveis de diferentes categorias (qualitativas e quantitativas) pode dificultar a análise e a interpretação dos resultados, muitas vezes resultando na incompleta distinção dos acessos. Este trabalho objetivou caracterizar 14 acessos de Cucurbita moschata coletados no Norte do Estado do Rio de Janeiro e estimar a divergência genotípica entre esses acessos, utilizando a análise conjunta de variáveis qualitativas e quantitativas. As plantas foram cultivadas a campo, no delineamento de blocos ao acaso, com três repetições e seis plantas por parcela. oito variáveis qualitativas (tamanho da folha; formato da semente; cor da semente; cor da polpa do fruto; reentrância; formato do fruto; cor predominante da casca e textura da superfície da casca) e oito variáveis quantitativas (massa do fruto; comprimento e diâmetro do fruto; teor de sólidos solúveis totais; massa de 100 sementes, e espessura da polpa no pedúnculo, mediana e inferior). Os dados foram analisados considerando a distância de Gower e o agrupamento dos acessos foi realizado pelo método UPGMA. Verificou-se variabilidade entre os aces...

Anthracnose, caused by Colletotrichum spp., is one of the most common diseases affecting sweet pepper and chilli pepper production worldwide, especially in tropical and subtropical zones. This disease results in severe fruit damage both pre‐ and postharvest. The development of resistant cultivars is the most effective strategy for disease control, which requires knowing the genetic basis of resistance. In this study, we analysed the inheritance of resistance of Capsicum annuum to Colletotrichum scovillei at two fruit development stages. The ripe and unripe fruits were inoculated by conidia suspension, and anthracnose severity was evaluated for 8 days using a score scale. It was found that the inheritance of resistance has independent expression in ripe and unripe fruits. In both cases, two main genes are responsible for resistance with polygenic effects. Genetic control, with a quantitative aspect, is more affected by dominance than the additive effects, in both fruit development stages of C. annuum.