Abstract The aim of this study was to evaluate the genetic variability and performance of the agronomic traits of wheat cultivars in the southern region of Minas Gerais for the purpose of choosing parents for a rainfed wheat breeding program. We evaluated 78 wheat cultivars in two locations in Minas Gerais regarding different agronomic traits. The statistical analyses were carried out using Henderson’s mixed-model approach. The genetic values of the cultivars were predicted, and the heritabilities and accuracies were estimated for selection of cultivars. The cultivar × location interaction was decomposed into its simple and complex fractions. The genetic and environmental correlations between the traits were estimated, and selection was made for multiple traits using the sum of the standardized variables (Z-index). The genetic variance was significant for all the traits, and the cultivar × location interaction was significant. By the Z-index, 15 wheat cultivars more adapted were identified.

Abstract We aimed to measure the efficiency of visual selection of plant vigor for green biomass production of U. ruziziensis using single- and multitrait approaches to maximize the predictive accuracy of the genetic value. The green biomass production and plant vigor of 254 U. ruziziensis clones were measured over nine evaluation cuttings to determine the efficiency of these approaches for production improvement. Individual and multicutting analyses were performed under single-trait and multitrait approaches using mixed models. The efficiency of visual selection was assessed by measuring plant vigor based on direct and indirect genetic gains. Plant vigor showed a high genetic association with green biomass and could be selected for production, especially in the initial phases of breeding programs. The multitrait approach was superior to the single-trait approach in predicting the genetic value of the clones, and it can be used in U. ruziziensis breeding programs.

Abstract The objective of this study was to evaluate the performance of hybrids and the heterosis in crosses of sweet sorghum using juicy sweet male-sterile lines and fertility-restoring lines with and without sensitivity to photoperiod. Thirty hybrids and six controls were evaluated in experiments laid out in a 6 × 6 triple lattice design. The genotypes differed for all traits. The general combining ability (GCA) of the R lines affected all traits, while the GCA of the A lines only affected juice extraction, total soluble solids, and tons of Brix per hectare (TBH). The photosensitive-restoring line CMSXS5022 had the highest positive GCA estimates for the fresh mass production and TBH traits. Heterosis was significant only for days to flowering and plant height. Overall, the photoperiod-sensitive hybrids stood out. The development of male-sterile lines requires better complementarity from restoring lines to reap the benefits of heterosis.

O conhecimento da diversidade genética entre acessos em bancos de germoplasma é importante para fins de conservação de recursos genéticos e uso em programas de melhoramento genético. Neste estudo, objetivou-se avaliar a divergência genética entre 23 acessos de pimentas do gênero Capsicum, a partir de sete descritores quantitativos e 19 qualitativos multicategóricos, com auxílio de técnicas multivariadas. Pela análise de variância, evidenciaram-se diferenças significativas entre os acessos de pimentas para todos os descritores quantitativos. Os coeficientes de variação (CV) do experimento variaram de 8,97 (LF) a 30,91% (NFA). O Método de agrupamento de otimização via Tocher detectou a formação de oito grupos, tanto para descritores quantitativos, quanto para os qualitativos multicategóricos. Pelo Método UPGMA, formaram-se três grupos baseando-se nos descritores quantitativos e quatro grupos com base nos qualitativos. Há diversidade genética inter e intraespecífica no Banco de Germoplasma de Capsicum spp. da Universidade Federal do Piauí, com evidências de que não existem duplicatas entre os acessos estudados.

The knowledge of the genetic diversity among the accessions in germplasm banks it is important for the conservation of genetic resources and the use in breeding programs. This study aimed to evaluate the genetic divergence of 23 accessions of the genus Capsicum, and was based in seven quantitative and nineteen qualitative multicategorical descriptors and using multivariate techniques. The analyses of variance revealed significant difference (P<0.05) among the accessions of peppers for all quantitative descriptors. The coefficient variation ranged from 8,97% (LF) to 30,91% (NFA). The Tocher optimization method detected eight clusters for quantitative descriptors and also in as well as qualitative multicategoric descriptors. The UPGMA method detected three clusters for quantitative descriptors and four clusters within qualitative multicategoricdescriptors. There is genetic diversity inter and intraspecific in germplasm bank of Capsicum coming from The Federal University of Piauí, and these results indicate that there are not duplicated accessions.