Genetic parameters for six quantitative traits in the early generation of segregating populations of common beans (Phaseolus vulgaris L.) were evaluated. A Bayesian approach was used for estimating the variance components, breeding values and broad sense heritability of the quantitative traits under analysis. The Markov Chain Monte Carlo method was utilized to analyze the contribution of genes affecting complex traits. Twenty-four F 3 families were evaluated in the field during 2005 in Santa Catarina, southern Brazil. With regard to the grain yield and yield components, the additive variances were relatively similar to the dominance variances. This result is confirmed by the 95% credible set from the posterior distribution. The mean estimates of broad-sense heritability (H 2 ) varied from 11.5% to 64.2%. The heritability estimates of yield and yield components were higher than the estimates for the number of days until flowering and reproductive period. However, for grain yield, the 95% heritability credible set included the heritability estimates from point of crop duration. The predicted genetic gain reached the highest value for the number of pods per plant (10.95%). Days to flowering and reproductive period had the lowest values of genetic advance. One hundred seed-weight, grain yield and seeds per pod exhibited a similar predictable level of genetic gain: GA = 5.73%, 5.81% and 4.77%, respectively. The Bayesian framework provided information that is useful for a breeding program, since it contributes to the understanding of how quantitative traits are genetically controlled.

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ABSTRACT. Diallel analysis was used to obtain information on combining ability, heterosis, estimates of genetic distances by random amplified polymorphic DNA (RAPD) and on their correlations with heterosis, for the popcorn varieties RS 20, UNB2, CMS 43, CMS 42, Zélia, UEM J1, UEM M2, Beija-Flor, and Viçosa, which were crossed to obtain all possible combinations, without reciprocals. The genitors and the 36 F 1 hybrids were evaluated in field trials in Maringá during two growing seasons in a randomized complete block design with three replications. Based on the results, strategies for further studies were developed, including the construction of composites by joining varieties with high general combining ability for grain yield (UNB2 and CMS 42) with those with high general combining ability for popping expansion (Zélia, RS 20 and UEM M2). Based on the RAPD markers, UEM J1 and Zélia were the most genetically distant and RS 20 and UNB2 were the most similar. The low correlation between heterosis and genetic distances may be explained by the random dispersion of the RAPD markers, which were insufficient for the exploitation of the popcorn genome. We concluded that an association between genetic dissimilarity and heterosis based only on genetic distance is not expected without considering the effect of dominant loci.

ABSTRACT. Brazil has only one public genetic pool of Bombyx mori strains, which was established in 2005 at Universidade Estadual de Maringá, Maringá, Paraná State. This genetic bank has been maintained, and the strains have been characterized using genetic and morphological tools. The quantitative and qualitative traits, directly or indirectly related to productivity, were evaluated in 14 silkworm strains. In addition to biological and productivity analyses, DNA markers related to susceptibility to the B. mori nucleopolyhedrovirus (BmNPV) were analyzed. BmNPV is a major cause of production loss and is a serious problem for Paraná sericulture. The silkworm strains from diverse geographic origins were found to have different characteristics, including body weight, larval stage duration, cocoon weight, and other biological traits. In terms of productivity, the raw silk percentages were almost uniform, with an overall average of 16.28%. Overall, the Chinese strain C37 gave the best performance in many of the quantitative traits, and it surpassed the other strains in productivity Genetic characterization of Brazilian B. mori germplasm bank traits. Therefore, it can be used as one of the strains that compose the elite germplasm for silkworm breeding programs. Additionally, genetic molecular markers were efficient in discriminating between B. mori strains that had been identified based on their geographical origin. We found that all Japanese strains produced a 400-bp molecular marker that has been associated with susceptibility to BmNPV.

The small noncoding group of RNAs called stem-bulge RNAs (sbRNAs), first reported in Caenorhabditis elegans, is described as molecules homologous to the Y RNAs, a specific class of noncoding RNAs that is present in vertebrates. This homology indicates the possibility of the existence of sbRNAs in other invertebrate organisms. In this work, we used bioinformatic tools and conserved sequences of sbRNAs from C. Elegans and Y RNAs to search for homologous sbRNA sequences in the Bombyx mori genome. This analysis led to the discovery of one noncoding gene, which was translated into RNA segments and comparatively analysed with segments from human and hamster Y RNAs and C. elegans sbRNAs in molecular dynamic simulations. This gene represents the first evidence for a new sbRNA-like noncoding RNA, the BmsbRNA gene, in this Lepidoptera genome.