Harvest season and seed physiological potential of ‘dedo-de-moça BRS Mari’ hot peppers

The cultivation of chili peppers (Capsicum spp.) plays a key role in the fresh vegetable, condiment, and preserve markets. The determination of the harvest season suitable for seed production is crucial to obtain high-quality seeds and ensure production success. Therefore, this study aimed to determine the harvest season of ‘dedo-de-moça BRS Mari’ hot peppers that provides the maximum seed physiological potential. The flowers in anthesis were labeled daily and the fruits were harvested 25, 40, 55, 70, 85, and 100 days after anthesis (DAA) and classified as green, yellowish green, orange, red, extreme red, and intense red, respectively. The seed physiological potential was determined by using the water content, dry matter, germination, first germination count, germination rate index, and accelerated aging tests. The seed dry matter increased steadily until 55 DAA (3.95 mg per seed), then increased slightly to 70 DAA (4.05 mg per seed), and stabilized from 85 to 100 DAA. The harvested seeds began to germinate at 55 DAA with approximately 40% germination, which peaked at 70 DAA with 87% germination; this value was maintained until 100 DAA. The highest values of the germination rate index were found at 70, 85, and 100 DAA. An increase in seed vigor was observed, based on the accelerated aging test, which peaked at 85 DAA and subsequently decreased. The peppers were harvested between 70 and 85 DAA and red to extreme red were found to be the most recommended colors to obtain ‘dedo-de-moça BRS Mari’ hot pepper seeds with high physiological potential

Citrus tristeza disease severity and agronomiC performanCe of 'pÊra' sweet orange CuLtivars and seLeCtions in the north and northwest regions of the state of paraná, BraziL 1

aBstraCt -'Pêra' sweet orange is the most important citrus cultivar in Brazil, but it is highly susceptible to Citrus tristeza virus (CTV), the causal agent of citrus tristeza disease. In this study, we evaluated the severity of citrus tristeza disease and its relation with the agronomic performance of seven cultivars and six selections of 'Pêra' sweet orange under field conditions in the North and Northwest regions of the State of Paraná, Brazil. The citrus tristeza disease severity was determined based on symptoms of stem pitting. The vegetative growth assessed in trees of all four locations for the 2012 season, and in two field plots for the 2011, 2012 and 2013 harvests, respectively. The cultivar 'IPR 153' (Bianchi) had the best performance concerning stem pitting severity, while Selection 27 was among the ones with the highest rate of vegetative growth. Further, Selections 27 and 12, and the cultivar 'Vimusa' had the largest fruit yields. Based on correlation analysis, stem pitting symptoms severity was negatively correlated with vegetative growth and fruit yield. Furthermore, environmental conditions may have played an important role in the severity of citrus tristeza disease and consequently on the agronomic performance of the cultivars and selections of 'Pêra' sweet orange in the North an

Citrus tristeza disease severity and agronomic performance of ‘Pêra’ sweet orange cultivars and selections in the North and Northwest regions of the State of Paraná, Brazil

ABSTRACT ‘Pêra’ sweet orange is the most important citrus cultivar in Brazil, but it is highly susceptible to Citrus tristeza virus (CTV), the causal agent of citrus tristeza disease. In this study, we evaluated the severity of citrus tristeza disease and its relation with the agronomic performance of seven cultivars and six selections of ‘Pêra’ sweet orange under field conditions in the North and Northwest regions of the State of Paraná, Brazil. The citrus tristeza disease severity was determined based on symptoms of stem pitting. The vegetative growth assessed in trees of all four locations for the 2012 season, and in two field plots for the 2011, 2012 and 2013 harvests, respectively. The cultivar ‘IPR 153’ (Bianchi) had the best performance concerning stem pitting severity, while Selection 27 was among the ones with the highest rate of vegetative growth. Further, Selections 27 and 12, and the cultivar ‘Vimusa’ had the largest fruit yields. Based on correlation analysis, stem pitting symptoms severity was negatively correlated with vegetative growth and fruit yield. Furthermore, environmental conditions may have played an important role in the severity of citrus tristeza disease and consequently on the agronomic performance of the cultivars and selections of ‘Pêra’ sweet orange in the North and Northwest regions of the State of Paraná

Genetic divergence among pumpkin landraces

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

An integrated analysis of mRNA and sRNA transcriptional profiles in Coffea arabica L. roots: insights on nitrogen starvation responses

International audienceCoffea arabica L. is an important agricultural commodity, accounting for 60% of traded coffee worldwide. Nitrogen (N) is a macronutrient that is usually limiting to plant yield; however, molecular mechanisms of plant acclimation to N limitation remain largely unknown in tropical woody crops. In this study, we investigated the transcriptome of coffee roots under N starvation, analyzing poly-A+ libraries and small RNAs. We also evaluated the concentration of selected amino acids and N-source preferences in roots. Ammonium was preferentially taken up over nitrate, and asparagine and glutamate were the most abundant amino acids observed in coffee roots. We obtained 34,654 assembled contigs by mRNA sequencing, and validated the transcriptional profile of 12 genes by RT-qPCR. Illumina small RNA sequencing yielded 8,524,332 non-redundant reads, resulting in the identification of 86 microRNA families targeting 253 genes. The transcriptional pattern of eight miRNA families was also validated. To our knowledge, this is the first catalog of differentially regulated amino acids, N sources, mRNAs, and sRNAs in Arabica coffee roots