In breeding of sweet sorghum hybrids, non-additive genetic effects are important in phenotypic expression of the traits of interest. The aim of this study was to evaluate the general combining ability (GCA) of sweet sorghum lines and the specific combining ability (SCA) of the hybrids for agronomic and technological traits. Five fertility restorer lines, four male-sterile lines, and their hybrids from partial diallel crosses were evaluated in experiments laid out in a 5 x 6 triple rectangular lattice design in the municipalities of Lavras, MG and Sete Lagoas, MG, Brazil. Diallel analysis was performed using the Griffing model adapted to partial diallel crosses. There was a significant effect of GCA and SCA for most of the traits evaluated, indicating the participation of additive or dominant genes in inheritance. The restorer lines CMSX508, BRS 511, CMSXS643, and CMSXS646 show potential for use as parents in sorghum breeding programs.

The biomass sorghum [Sorghum bicolor (L.) Moench], is an interesting crop considering the necessity to invest in alternative sources to generate renewable energy. The objective of this experiment was to identify sorghum biomass genotypes with greatest agronomic and energetic potential, and verify if there is phenotypic association between agronomic and technological properties in the hybrids. The study was conducted in three cities of the Minas Gerais State, Brazil (Lavras, Uberlândia and Sete Lagoas). We evaluated 16 genotypes of sorghum biomass, being 14 of them sensitive hybrids to photoperiod and two cultivars, as control, insensitive to photoperiod. The experimental design was a triple lattice 4 × 4, with plots formed by four linear rows of 5.0 m. The morphoagronomic traits evaluated for the three environments were: days to flowering (FLOW), plant height (PH), number of stalks (NS) and green mass production (GMP). In the experiment conducted in Lavras, we also evaluated the agronomic traits: stalk diameter (SD) and dry mass production (DMP) besides the technological traits: higher heating value (HHV), crude fiber (CF), neutral detergent fiber (NDF) and acid detergent fiber (ADF). The genotype × environment interaction was significant for all traits. The hybrids had superior performance compared to the control genotypes. Biomass sorghum hybrids, sensitive to photoperiod, when compared with commercial hybrids of forage sorghum, insensitive to photoperiod, had an average production of 34 t ha −1 dry mass with 62% humidity and higher heating value of 4.400 Kcal/Kg. There was no phenotypic correlation between agronomic and technological traits evaluated.

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The objective of this work was to evaluate the potential per se of male-sterile and fertility-restorer lines of sweet sorghum (Sorghum bicolor), as well as to detail the heterosis manifested for some traits directly or indirectly related to ethanol production, accumulation rate, and predictability. Evaluations were performed for 20 genotypes, of which 4 are fertility-restorer lines (R), 3 are male-sterile lines (A), and 12 are experimental hybrids (H) resulting from the partial diallel cross between lines A and R, besides a commercial hybrid CV198 used as a check, in four harvest seasons. The experiments were carried out in the municipalities of Lavras and Sete Lagoas, in the state of Minas Gerais, Brazil. The measured traits were plant height, green mass production, juice extraction, total soluble solids content, and megagrams of Brix per hectare. The male-sterile A1 and the fertility-restorer R1 and R3 lines show the best potential per se, considering all traits and their accumulation rate and predictability over harvest times. Heterosis is significant for all traits. The H11, H13, H14, H21, H22, and H33 hybrids are promising because of their better performance per se and higher heterosis.

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