The aim of this work was to estimate the general and specific combining ability of peppers by measuring fruit quality and yield traits. This experiment was carried out on the garden field from Universidade Federal de Viçosa (UFV), Minas Gerais State-Brazil. Eight lines of Capsicum baccatum belonging to the UFV Horticultural Germplasm Bank were chosen based on their broad genetic and phenotypical background variation and then they were crossed in a complete diallel way. The F 1 seeds of the 56 hybrids and eight parents were planted in the field in a randomized complete block design. The data were submitted to ANOVA and the means were grouped by Scott-Knott test (P B 0.01). Significant variation for fruit quality and yield components was observed among parents and F 1 generation. Analysis of variance for the combining ability showed that GCA effects exhibited significant difference and SCA effects of the crosses were significant, except for the height of first bifurcation. For almost all characters both additive and non-additive effects influenced the performance of hybrids.

The melt rheological properties of both linear and branched polyethylene were investigated by use of narrow molecular weight distribution fractions and experimentally polymerized samples. Studies carried out in steady shear and in oscillatory shear yielded information concerning both the melt viscosity and the melt elasticity as a function of molecular structure, where the latter was characterized by various solution property techniques. The 3.4–3.5 power dependence of the low shear limiting viscosity on molecular weight was confirmed for linear polyethylene. The effect of long‐chain branching on rheological properties was defined both at constant molecular weight and at constant molecular weight distribution and coupled with variation of molecular weight.

The hot peppers belonging to the species C. baccatum are completely restricted to Latin America and comprise the most popular hot pepper consumed as fresh or as processed paprika in Andean countries. The objective of this study was to characterize the phenotypic diversity among 40 landrace accessions of C. baccatum based on morphological fruit quality traits and yield components, and to determine the correlation between these characters and their contribution for the genetic variability. The accessions were analyzed for 14 fruit and plant descriptors. Plants were arranged as randomized complete block with three replicates. Collected data were initially subjected to analysis of variance and if the F-test was significant at P B 0.01, the averages were grouped by Scott-Knott criteria. The heritability in a broad sense and phenotypic correlation were calculated. The phenotypic divergence and relative importance were estimated by multivariate analysis. Significant differences for all traits were observed by F-test (P B 0.01). The range of heritability values were between 83.2 and 99.1. The landraces were grouped in seven different clusters. Major fruit width, fruit weight and fruit dry matter were the only fruit traits with positive correlation with yield. Plant width, height, first bifurcation height and fruit set were positive correlated between them and with yield. Based on the data, the most divergent accessions were 4 and 24, which could result in higher heterotic effect in eventual hybridizations between them. The results of this study showed that spice and vegetable type specific varieties can be developed from C. baccatum.

On the basis of the biological compounds that they metabolize, plant peroxidases have long been implicated in plant growth, cell wall biogenesis, lignification, and host defenses. Transgenic tobacco (Nicotiana tabacum L.) plants that underexpress anionic peroxidase were generated using antisense RNA. The antisense RNA was found to be specific for the anionic isoenzyme and highly effective, reducing endogenous transcript levels and total peroxidase activity by as much as 1600-fold. Antisense-transformed plants appeared normal at initial observation; however, growth studies showed that plants with reduced peroxidase activity grow taller and flower sooner than control plants. In contrast, previously transformed plants overproducing anionic peroxidase were shorter and flowered later than controls. Axillary buds were more developed in antisensetransformed plants and less developed in plants overproducing this enzyme. It was found that the lignin content in leaf, stem, and root was unchanged in antisense-transformed plants, which does not support a role for anionic peroxidase in the lignification of secondary xylem vessels. However, studies of wounded tissue show some reduction in wound-induced deposition of lignin-like polymers. The data support a possible role for tobacco anionic peroxidase in host defenses but not without a reduction in growth potential.

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