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The Urochloa spp. breeding program at EMBRAPA‐Brazil targets the development of apomictic hybrids to improve animal performance, while reducing the environmental impact of livestock. In summary, breeders perform multiple crosses between apomictic and sexual parents, and screen progeny to perform selections for agronomic and nutritional traits across several harvests, years and locations. Thus, choosing the right parents and the cross combinations is crucial for the success of the breeding program. The objectives of this study were to: (i) estimate the general (GCA) and specific (SCA) combining ability, and contribution of additive and nonadditive effects, from a partial diallel cross design between three apomictic and ten sexual parents, for agronomical and nutritional traits in Urochloa spp.; (ii) assess genetic gain for all traits by selecting for yield of high nutritional value leaf mass (NLM); (iii) characterize the genotype profiles using genotype by yield*trait (GYT) biplot analysis. A total of 1380 interspecific hybrids from 29 full‐sib progenies were evaluated and then the hybrid selection was performed based on studentized best linear unbiased prediction of NLM. The 10% top‐performing hybrids were used in the GYT analysis using NLM as the basic variable. There was a predominance of nonadditive effects on the phenotypic expression of agronomic and nutritional value traits. The GCA was observed only for some traits in sexual parents, whereas SCA was observed in all traits. The selection based on NLM provided favorable gains for most of the agronomic traits and GYT biplot analysis was efficient to characterize genotype profiles. [ABSTRACT FROM AUTHOR]

Forage peanut (Arachis pintoi) is considered a legume ideotype for use in mixed pastures in humid tropical regions, but its adoption has been hindered by low availability and high prices of commercial seeds. However, there is a concern if breeding of high seed‐yielding cultivars could result in loss of compatibility with grasses. This study compared the competitive ability and spreading ability of 12 forage peanut genotypes with contrasting seed‐yielding potential in mixtures with Brachiaria humidicola in northern Brazil. These genotypes were previously selected for high performance under clipping in pure stands. Twenty‐five rooted stolons of forage peanut were transplanted to the central area (1 × 1 m) of each plot (5 × 5 m) seeded 35 days before with B. humidicola. The experiment used a randomized complete block design with five replicates per genotype and was evaluated under grazing from 6 to 30 months after pasture establishment using the intermittent stocking method. All genotypes persisted and increased their proportion in botanical composition over time. Spread of forage peanut stolons into surrounding B. humidicola sward varied from 0.56 to 1.46 m/year. Cultivar BRS Mandobi had the greatest competitive ability and cultivar Belomonte the greatest spreading ability. Two genotypes (cv. BRS Mandobi and accession BRA‐00064752‐9) were selected combining high seed‐yielding and high compatibility with B. humidicola. This is evidence that both traits (compatibility with grasses and seed yield) can be simultaneously improved in this legume. The results are discussed in terms of the ecology of grass‐legume mixtures and breeding of forage peanut. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the resistance of B. ruziziensis clones to the spittlebug species Deois schach and Mahanarva spectabilis. Together with the cultivar Marandu (B. brizantha) and the progenies 77s, 85s and 106s as controls, 71 B. ruziziensis clones were evaluated in a randomized block design. Six spittlebug eggs about to hatch were artificially infested and 40 days later evaluated for the percentage of surviving nymphs and plant damage based on a rating scale. Analysis of variance identified significant differences for nymph survival and plant damage of both spittlebug species. Since nymph survival and damage scores of the clones 100, 95, 19, 42, 93, 4, 92, 47, 26, 63, and 58 were similar to Marandu, these can be considered resistant to insect pests. These results, besides demonstrating the existence of genetic variability for a possible selection, offer hope for an identification of B. ruziziensis spittlebug-resistant genotypes. [ABSTRACT FROM AUTHOR]